Changeset 1857


Ignore:
Timestamp:
Sep 3, 2012, 2:12:46 PM (7 years ago)
Author:
fielding@…
Message:

(editorial) move header field definitions into categories

Location:
draft-ietf-httpbis/latest
Files:
2 edited

Legend:

Unmodified
Added
Removed

  • draft-ietf-httpbis/latest/p2-semantics.html

    r1856 r1857  
    480480      <link rel="Chapter" title="8 Response Header Fields" href="#rfc.section.8">
    481481      <link rel="Chapter" title="9 Protocol Parameters" href="#rfc.section.9">
    482       <link rel="Chapter" title="10 Header Field Definitions" href="#rfc.section.10">
    483       <link rel="Chapter" title="11 IANA Considerations" href="#rfc.section.11">
    484       <link rel="Chapter" title="12 Security Considerations" href="#rfc.section.12">
    485       <link rel="Chapter" title="13 Acknowledgments" href="#rfc.section.13">
    486       <link rel="Chapter" href="#rfc.section.14" title="14 References">
     482      <link rel="Chapter" title="10 IANA Considerations" href="#rfc.section.10">
     483      <link rel="Chapter" title="11 Security Considerations" href="#rfc.section.11">
     484      <link rel="Chapter" title="12 Acknowledgments" href="#rfc.section.12">
     485      <link rel="Chapter" href="#rfc.section.13" title="13 References">
    487486      <link rel="Appendix" title="A Differences between HTTP and MIME" href="#rfc.section.A">
    488487      <link rel="Appendix" title="B Additional Features" href="#rfc.section.B">
    … …  
    588587         <li><a href="#rfc.section.3">3.</a>&nbsp;&nbsp;&nbsp;<a href="#representation">Representation</a><ul>
    589588               <li><a href="#rfc.section.3.1">3.1</a>&nbsp;&nbsp;&nbsp;<a href="#identifying.response.associated.with.representation">Identifying the Resource Associated with a Representation</a></li>
    590                <li><a href="#rfc.section.3.2">3.2</a>&nbsp;&nbsp;&nbsp;<a href="#representation.header.fields">Representation Header Fields</a></li>
    591                <li><a href="#rfc.section.3.3">3.3</a>&nbsp;&nbsp;&nbsp;<a href="#representation.data">Representation Data</a></li>
    592                <li><a href="#rfc.section.3.4">3.4</a>&nbsp;&nbsp;&nbsp;<a href="#content.negotiation">Content Negotiation</a><ul>
    593                      <li><a href="#rfc.section.3.4.1">3.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#server-driven.negotiation">Server-driven Negotiation</a></li>
    594                      <li><a href="#rfc.section.3.4.2">3.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#agent-driven.negotiation">Agent-driven Negotiation</a></li>
    595                      <li><a href="#rfc.section.3.4.3">3.4.3</a>&nbsp;&nbsp;&nbsp;<a href="#quality.values">Quality Values</a></li>
     589               <li><a href="#rfc.section.3.2">3.2</a>&nbsp;&nbsp;&nbsp;<a href="#representation.header.fields">Representation Header Fields</a><ul>
     590                     <li><a href="#rfc.section.3.2.1">3.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-type">Content-Type</a></li>
     591                     <li><a href="#rfc.section.3.2.2">3.2.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-encoding">Content-Encoding</a></li>
     592                     <li><a href="#rfc.section.3.2.3">3.2.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-language">Content-Language</a></li>
     593                     <li><a href="#rfc.section.3.2.4">3.2.4</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-location">Content-Location</a></li>
     594                  </ul>
     595               </li>
     596               <li><a href="#rfc.section.3.3">3.3</a>&nbsp;&nbsp;&nbsp;<a href="#selected.representation">Selected Representation Header Fields</a></li>
     597               <li><a href="#rfc.section.3.4">3.4</a>&nbsp;&nbsp;&nbsp;<a href="#representation.data">Representation Data</a></li>
     598               <li><a href="#rfc.section.3.5">3.5</a>&nbsp;&nbsp;&nbsp;<a href="#content.negotiation">Content Negotiation</a><ul>
     599                     <li><a href="#rfc.section.3.5.1">3.5.1</a>&nbsp;&nbsp;&nbsp;<a href="#server-driven.negotiation">Server-driven Negotiation</a></li>
     600                     <li><a href="#rfc.section.3.5.2">3.5.2</a>&nbsp;&nbsp;&nbsp;<a href="#agent-driven.negotiation">Agent-driven Negotiation</a></li>
    596601                  </ul>
    597602               </li>
    … …  
    625630         </li>
    626631         <li><a href="#rfc.section.6">6.</a>&nbsp;&nbsp;&nbsp;<a href="#request.header.fields">Request Header Fields</a><ul>
    627                <li><a href="#rfc.section.6.1">6.1</a>&nbsp;&nbsp;&nbsp;<a href="#request.controls">Controls</a></li>
     632               <li><a href="#rfc.section.6.1">6.1</a>&nbsp;&nbsp;&nbsp;<a href="#request.controls">Controls</a><ul>
     633                     <li><a href="#rfc.section.6.1.1">6.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.max-forwards">Max-Forwards</a></li>
     634                     <li><a href="#rfc.section.6.1.2">6.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.expect">Expect</a></li>
     635                  </ul>
     636               </li>
    628637               <li><a href="#rfc.section.6.2">6.2</a>&nbsp;&nbsp;&nbsp;<a href="#request.conditionals">Conditionals</a></li>
    629                <li><a href="#rfc.section.6.3">6.3</a>&nbsp;&nbsp;&nbsp;<a href="#request.conneg">Content Negotiation</a></li>
     638               <li><a href="#rfc.section.6.3">6.3</a>&nbsp;&nbsp;&nbsp;<a href="#request.conneg">Content Negotiation</a><ul>
     639                     <li><a href="#rfc.section.6.3.1">6.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#quality.values">Quality Values</a></li>
     640                     <li><a href="#rfc.section.6.3.2">6.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept">Accept</a></li>
     641                     <li><a href="#rfc.section.6.3.3">6.3.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-charset">Accept-Charset</a></li>
     642                     <li><a href="#rfc.section.6.3.4">6.3.4</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-encoding">Accept-Encoding</a></li>
     643                     <li><a href="#rfc.section.6.3.5">6.3.5</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-language">Accept-Language</a></li>
     644                  </ul>
     645               </li>
    630646               <li><a href="#rfc.section.6.4">6.4</a>&nbsp;&nbsp;&nbsp;<a href="#request.auth">Authentication</a></li>
    631                <li><a href="#rfc.section.6.5">6.5</a>&nbsp;&nbsp;&nbsp;<a href="#request.context">Context</a></li>
     647               <li><a href="#rfc.section.6.5">6.5</a>&nbsp;&nbsp;&nbsp;<a href="#request.context">Context</a><ul>
     648                     <li><a href="#rfc.section.6.5.1">6.5.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.from">From</a></li>
     649                     <li><a href="#rfc.section.6.5.2">6.5.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.referer">Referer</a></li>
     650                     <li><a href="#rfc.section.6.5.3">6.5.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.user-agent">User-Agent</a></li>
     651                  </ul>
     652               </li>
    632653            </ul>
    633654         </li>
    … …  
    688709         </li>
    689710         <li><a href="#rfc.section.8">8.</a>&nbsp;&nbsp;&nbsp;<a href="#response.header.fields">Response Header Fields</a><ul>
    690                <li><a href="#rfc.section.8.1">8.1</a>&nbsp;&nbsp;&nbsp;<a href="#response.control.data">Control Data</a></li>
    691                <li><a href="#rfc.section.8.2">8.2</a>&nbsp;&nbsp;&nbsp;<a href="#response.cache.related">Cache-related</a></li>
     711               <li><a href="#rfc.section.8.1">8.1</a>&nbsp;&nbsp;&nbsp;<a href="#response.control.data">Control Data</a><ul>
     712                     <li><a href="#rfc.section.8.1.1">8.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.location">Location</a></li>
     713                     <li><a href="#rfc.section.8.1.2">8.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.retry-after">Retry-After</a></li>
     714                  </ul>
     715               </li>
     716               <li><a href="#rfc.section.8.2">8.2</a>&nbsp;&nbsp;&nbsp;<a href="#response.cache.related">Cache-related</a><ul>
     717                     <li><a href="#rfc.section.8.2.1">8.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.date">Date</a></li>
     718                  </ul>
     719               </li>
    692720               <li><a href="#rfc.section.8.3">8.3</a>&nbsp;&nbsp;&nbsp;<a href="#response.auth">Authentication Challenges</a></li>
    693                <li><a href="#rfc.section.8.4">8.4</a>&nbsp;&nbsp;&nbsp;<a href="#response.inform">Informative</a></li>
     721               <li><a href="#rfc.section.8.4">8.4</a>&nbsp;&nbsp;&nbsp;<a href="#response.inform">Informative</a><ul>
     722                     <li><a href="#rfc.section.8.4.1">8.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.allow">Allow</a></li>
     723                     <li><a href="#rfc.section.8.4.2">8.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.server">Server</a></li>
     724                  </ul>
     725               </li>
    694726            </ul>
    695727         </li>
    … …  
    707739            </ul>
    708740         </li>
    709          <li><a href="#rfc.section.10">10.</a>&nbsp;&nbsp;&nbsp;<a href="#header.field.definitions">Header Field Definitions</a><ul>
    710                <li><a href="#rfc.section.10.1">10.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept">Accept</a></li>
    711                <li><a href="#rfc.section.10.2">10.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-charset">Accept-Charset</a></li>
    712                <li><a href="#rfc.section.10.3">10.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-encoding">Accept-Encoding</a></li>
    713                <li><a href="#rfc.section.10.4">10.4</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-language">Accept-Language</a></li>
    714                <li><a href="#rfc.section.10.5">10.5</a>&nbsp;&nbsp;&nbsp;<a href="#header.allow">Allow</a></li>
    715                <li><a href="#rfc.section.10.6">10.6</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-encoding">Content-Encoding</a></li>
    716                <li><a href="#rfc.section.10.7">10.7</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-language">Content-Language</a></li>
    717                <li><a href="#rfc.section.10.8">10.8</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-location">Content-Location</a></li>
    718                <li><a href="#rfc.section.10.9">10.9</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-type">Content-Type</a></li>
    719                <li><a href="#rfc.section.10.10">10.10</a>&nbsp;&nbsp;&nbsp;<a href="#header.date">Date</a></li>
    720                <li><a href="#rfc.section.10.11">10.11</a>&nbsp;&nbsp;&nbsp;<a href="#header.expect">Expect</a></li>
    721                <li><a href="#rfc.section.10.12">10.12</a>&nbsp;&nbsp;&nbsp;<a href="#header.from">From</a></li>
    722                <li><a href="#rfc.section.10.13">10.13</a>&nbsp;&nbsp;&nbsp;<a href="#header.location">Location</a></li>
    723                <li><a href="#rfc.section.10.14">10.14</a>&nbsp;&nbsp;&nbsp;<a href="#header.max-forwards">Max-Forwards</a></li>
    724                <li><a href="#rfc.section.10.15">10.15</a>&nbsp;&nbsp;&nbsp;<a href="#header.referer">Referer</a></li>
    725                <li><a href="#rfc.section.10.16">10.16</a>&nbsp;&nbsp;&nbsp;<a href="#header.retry-after">Retry-After</a></li>
    726                <li><a href="#rfc.section.10.17">10.17</a>&nbsp;&nbsp;&nbsp;<a href="#header.server">Server</a></li>
    727                <li><a href="#rfc.section.10.18">10.18</a>&nbsp;&nbsp;&nbsp;<a href="#header.user-agent">User-Agent</a></li>
    728             </ul>
    729          </li>
    730          <li><a href="#rfc.section.11">11.</a>&nbsp;&nbsp;&nbsp;<a href="#IANA.considerations">IANA Considerations</a><ul>
    731                <li><a href="#rfc.section.11.1">11.1</a>&nbsp;&nbsp;&nbsp;<a href="#method.registry">Method Registry</a><ul>
    732                      <li><a href="#rfc.section.11.1.1">11.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#method.procedure">Procedure</a></li>
    733                      <li><a href="#rfc.section.11.1.2">11.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#considerations.for.new.methods">Considerations for New Methods</a></li>
    734                      <li><a href="#rfc.section.11.1.3">11.1.3</a>&nbsp;&nbsp;&nbsp;<a href="#method.registration">Registrations</a></li>
     741         <li><a href="#rfc.section.10">10.</a>&nbsp;&nbsp;&nbsp;<a href="#IANA.considerations">IANA Considerations</a><ul>
     742               <li><a href="#rfc.section.10.1">10.1</a>&nbsp;&nbsp;&nbsp;<a href="#method.registry">Method Registry</a><ul>
     743                     <li><a href="#rfc.section.10.1.1">10.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#method.procedure">Procedure</a></li>
     744                     <li><a href="#rfc.section.10.1.2">10.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#considerations.for.new.methods">Considerations for New Methods</a></li>
     745                     <li><a href="#rfc.section.10.1.3">10.1.3</a>&nbsp;&nbsp;&nbsp;<a href="#method.registration">Registrations</a></li>
    735746                  </ul>
    736747               </li>
    737                <li><a href="#rfc.section.11.2">11.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.code.registry">Status Code Registry</a><ul>
    738                      <li><a href="#rfc.section.11.2.1">11.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.code.procedure">Procedure</a></li>
    739                      <li><a href="#rfc.section.11.2.2">11.2.2</a>&nbsp;&nbsp;&nbsp;<a href="#considerations.for.new.status.codes">Considerations for New Status Codes</a></li>
    740                      <li><a href="#rfc.section.11.2.3">11.2.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.code.registration">Registrations</a></li>
     748               <li><a href="#rfc.section.10.2">10.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.code.registry">Status Code Registry</a><ul>
     749                     <li><a href="#rfc.section.10.2.1">10.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.code.procedure">Procedure</a></li>
     750                     <li><a href="#rfc.section.10.2.2">10.2.2</a>&nbsp;&nbsp;&nbsp;<a href="#considerations.for.new.status.codes">Considerations for New Status Codes</a></li>
     751                     <li><a href="#rfc.section.10.2.3">10.2.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.code.registration">Registrations</a></li>
    741752                  </ul>
    742753               </li>
    743                <li><a href="#rfc.section.11.3">11.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.field.registry">Header Field Registry</a><ul>
    744                      <li><a href="#rfc.section.11.3.1">11.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#considerations.for.new.header.fields">Considerations for New Header Fields</a></li>
    745                      <li><a href="#rfc.section.11.3.2">11.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.field.registration">Registrations</a></li>
     754               <li><a href="#rfc.section.10.3">10.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.field.registry">Header Field Registry</a><ul>
     755                     <li><a href="#rfc.section.10.3.1">10.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#considerations.for.new.header.fields">Considerations for New Header Fields</a></li>
     756                     <li><a href="#rfc.section.10.3.2">10.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.field.registration">Registrations</a></li>
    746757                  </ul>
    747758               </li>
    748                <li><a href="#rfc.section.11.4">11.4</a>&nbsp;&nbsp;&nbsp;<a href="#content.coding.registry">Content Coding Registry</a><ul>
    749                      <li><a href="#rfc.section.11.4.1">11.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#content.coding.procedure">Procedure</a></li>
    750                      <li><a href="#rfc.section.11.4.2">11.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#content.coding.registration">Registrations</a></li>
     759               <li><a href="#rfc.section.10.4">10.4</a>&nbsp;&nbsp;&nbsp;<a href="#content.coding.registry">Content Coding Registry</a><ul>
     760                     <li><a href="#rfc.section.10.4.1">10.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#content.coding.procedure">Procedure</a></li>
     761                     <li><a href="#rfc.section.10.4.2">10.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#content.coding.registration">Registrations</a></li>
    751762                  </ul>
    752763               </li>
    753764            </ul>
    754765         </li>
    755          <li><a href="#rfc.section.12">12.</a>&nbsp;&nbsp;&nbsp;<a href="#security.considerations">Security Considerations</a><ul>
    756                <li><a href="#rfc.section.12.1">12.1</a>&nbsp;&nbsp;&nbsp;<a href="#security.sensitive">Transfer of Sensitive Information</a></li>
    757                <li><a href="#rfc.section.12.2">12.2</a>&nbsp;&nbsp;&nbsp;<a href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></li>
    758                <li><a href="#rfc.section.12.3">12.3</a>&nbsp;&nbsp;&nbsp;<a href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></li>
    759                <li><a href="#rfc.section.12.4">12.4</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.12.4">Security Considerations for CONNECT</a></li>
    760                <li><a href="#rfc.section.12.5">12.5</a>&nbsp;&nbsp;&nbsp;<a href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></li>
     766         <li><a href="#rfc.section.11">11.</a>&nbsp;&nbsp;&nbsp;<a href="#security.considerations">Security Considerations</a><ul>
     767               <li><a href="#rfc.section.11.1">11.1</a>&nbsp;&nbsp;&nbsp;<a href="#security.sensitive">Transfer of Sensitive Information</a></li>
     768               <li><a href="#rfc.section.11.2">11.2</a>&nbsp;&nbsp;&nbsp;<a href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></li>
     769               <li><a href="#rfc.section.11.3">11.3</a>&nbsp;&nbsp;&nbsp;<a href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></li>
     770               <li><a href="#rfc.section.11.4">11.4</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.11.4">Security Considerations for CONNECT</a></li>
     771               <li><a href="#rfc.section.11.5">11.5</a>&nbsp;&nbsp;&nbsp;<a href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></li>
    761772            </ul>
    762773         </li>
    763          <li><a href="#rfc.section.13">13.</a>&nbsp;&nbsp;&nbsp;<a href="#acks">Acknowledgments</a></li>
    764          <li><a href="#rfc.section.14">14.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references">References</a><ul>
    765                <li><a href="#rfc.section.14.1">14.1</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references.1">Normative References</a></li>
    766                <li><a href="#rfc.section.14.2">14.2</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references.2">Informative References</a></li>
     774         <li><a href="#rfc.section.12">12.</a>&nbsp;&nbsp;&nbsp;<a href="#acks">Acknowledgments</a></li>
     775         <li><a href="#rfc.section.13">13.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references">References</a><ul>
     776               <li><a href="#rfc.section.13.1">13.1</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references.1">Normative References</a></li>
     777               <li><a href="#rfc.section.13.2">13.2</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references.2">Informative References</a></li>
    767778            </ul>
    768779         </li>
    … …  
    917928            <tbody>
    918929               <tr>
     930                  <td class="left">Content-Type</td>
     931                  <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section&nbsp;3.2.1</a></td>
     932               </tr>
     933               <tr>
    919934                  <td class="left">Content-Encoding</td>
    920                   <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section&nbsp;10.6</a></td>
     935                  <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section&nbsp;3.2.2</a></td>
    921936               </tr>
    922937               <tr>
    923938                  <td class="left">Content-Language</td>
    924                   <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section&nbsp;10.7</a></td>
     939                  <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section&nbsp;3.2.3</a></td>
    925940               </tr>
    926941               <tr>
    927942                  <td class="left">Content-Location</td>
    928                   <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section&nbsp;10.8</a></td>
    929                </tr>
    930                <tr>
    931                   <td class="left">Content-Type</td>
    932                   <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section&nbsp;10.9</a></td>
     943                  <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section&nbsp;3.2.4</a></td>
    933944               </tr>
    934945               <tr>
    … …  
    939950         </table>
    940951      </div>
    941       <p id="rfc.section.3.2.p.3"><span id="rfc.iref.s.1"></span> We use the term "<dfn>selected representation</dfn>" to refer to the the current representation of a target resource that would have been selected in a successful response if
     952      <div id="rfc.iref.c.2"></div>
     953      <div id="rfc.iref.h.1"></div>
     954      <h3 id="rfc.section.3.2.1"><a href="#rfc.section.3.2.1">3.2.1</a>&nbsp;<a id="header.content-type" href="#header.content-type">Content-Type</a></h3>
     955      <p id="rfc.section.3.2.1.p.1">The "Content-Type" header field indicates the media type of the representation. In the case of responses to the HEAD method,
     956         the media type is that which would have been sent had the request been a GET.
     957      </p>
     958      <div id="rfc.figure.u.1"></div><pre class="inline"><span id="rfc.iref.g.1"></span>  <a href="#header.content-type" class="smpl">Content-Type</a> = <a href="#media.types" class="smpl">media-type</a>
     959</pre><p id="rfc.section.3.2.1.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section&nbsp;9.5</a>. An example of the field is
     960      </p>
     961      <div id="rfc.figure.u.2"></div><pre class="text">  Content-Type: text/html; charset=ISO-8859-4
     962</pre><p id="rfc.section.3.2.1.p.5">Further discussion of Content-Type is provided in <a href="#representation.data" title="Representation Data">Section&nbsp;3.4</a>.
     963      </p>
     964      <div id="rfc.iref.c.3"></div>
     965      <div id="rfc.iref.h.2"></div>
     966      <h3 id="rfc.section.3.2.2"><a href="#rfc.section.3.2.2">3.2.2</a>&nbsp;<a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h3>
     967      <p id="rfc.section.3.2.2.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent
     968         in the media type, and thus what decoding mechanisms have to be applied in order to obtain the media-type referenced by the <a href="#header.content-type" class="smpl">Content-Type</a> header field. Content-Encoding is primarily used to allow a representation to be compressed without losing the identity of
     969         its underlying media type.
     970      </p>
     971      <div id="rfc.figure.u.3"></div><pre class="inline"><span id="rfc.iref.g.2"></span>  <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = 1#<a href="#content.codings" class="smpl">content-coding</a>
     972</pre><p id="rfc.section.3.2.2.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section&nbsp;9.4</a>. An example of its use is
     973      </p>
     974      <div id="rfc.figure.u.4"></div><pre class="text">  Content-Encoding: gzip
     975</pre><p id="rfc.section.3.2.2.p.5">The content-coding is a characteristic of the representation. Typically, the representation body is stored with this encoding
     976         and is only decoded before rendering or analogous usage. However, a transforming proxy <em class="bcp14">MAY</em> modify the content-coding if the new coding is known to be acceptable to the recipient, unless the "no-transform" cache-control
     977         directive is present in the message.
     978      </p>
     979      <p id="rfc.section.3.2.2.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would
     980         not be restated as a Content-Encoding even if it happens to be the same algorithm as one of the content-codings. Such a content-coding
     981         would only be listed if, for some bizarre reason, it is applied a second time to form the representation. Likewise, an origin
     982         server might choose to publish the same payload data as multiple representations that differ only in whether the coding is
     983         defined as part of <a href="#header.content-type" class="smpl">Content-Type</a> or Content-Encoding, since some user agents will behave differently in their handling of each response (e.g., open a "Save
     984         as ..." dialog instead of automatic decompression and rendering of content).
     985      </p>
     986      <p id="rfc.section.3.2.2.p.7">A representation that has a content-coding applied to it <em class="bcp14">MUST</em> include a Content-Encoding header field that lists the content-coding(s) applied.
     987      </p>
     988      <p id="rfc.section.3.2.2.p.8">If multiple encodings have been applied to a representation, the content codings <em class="bcp14">MUST</em> be listed in the order in which they were applied. Additional information about the encoding parameters <em class="bcp14">MAY</em> be provided by other header fields not defined by this specification.
     989      </p>
     990      <p id="rfc.section.3.2.2.p.9">If the content-coding of a representation in a request message is not acceptable to the origin server, the server <em class="bcp14">SHOULD</em> respond with a status code of 415 (Unsupported Media Type).
     991      </p>
     992      <div id="rfc.iref.c.4"></div>
     993      <div id="rfc.iref.h.3"></div>
     994      <h3 id="rfc.section.3.2.3"><a href="#rfc.section.3.2.3">3.2.3</a>&nbsp;<a id="header.content-language" href="#header.content-language">Content-Language</a></h3>
     995      <p id="rfc.section.3.2.3.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note
     996         that this might not be equivalent to all the languages used within the representation.
     997      </p>
     998      <div id="rfc.figure.u.5"></div><pre class="inline"><span id="rfc.iref.g.3"></span>  <a href="#header.content-language" class="smpl">Content-Language</a> = 1#<a href="#language.tags" class="smpl">language-tag</a>
     999</pre><p id="rfc.section.3.2.3.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;9.6</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the
     1000         user's own preferred language. Thus, if the body content is intended only for a Danish-literate audience, the appropriate
     1001         field is
     1002      </p>
     1003      <div id="rfc.figure.u.6"></div><pre class="text">  Content-Language: da
     1004</pre><p id="rfc.section.3.2.3.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean
     1005         that the sender does not consider it to be specific to any natural language, or that the sender does not know for which language
     1006         it is intended.
     1007      </p>
     1008      <p id="rfc.section.3.2.3.p.6">Multiple languages <em class="bcp14">MAY</em> be listed for content that is intended for multiple audiences. For example, a rendition of the "Treaty of Waitangi", presented
     1009         simultaneously in the original Maori and English versions, would call for
     1010      </p>
     1011      <div id="rfc.figure.u.7"></div><pre class="text">  Content-Language: mi, en
     1012</pre><p id="rfc.section.3.2.3.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple
     1013         linguistic audiences. An example would be a beginner's language primer, such as "A First Lesson in Latin", which is clearly
     1014         intended to be used by an English-literate audience. In this case, the Content-Language would properly only include "en".
     1015      </p>
     1016      <p id="rfc.section.3.2.3.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents.
     1017      </p>
     1018      <div id="rfc.iref.c.5"></div>
     1019      <div id="rfc.iref.h.4"></div>
     1020      <h3 id="rfc.section.3.2.4"><a href="#rfc.section.3.2.4">3.2.4</a>&nbsp;<a id="header.content-location" href="#header.content-location">Content-Location</a></h3>
     1021      <p id="rfc.section.3.2.4.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this
     1022         message. In other words, if one were to perform a GET on this URI at the time of this message's generation, then a <a href="#status.200" class="smpl">200 (OK)</a> response would contain the same representation that is enclosed as payload in this message.
     1023      </p>
     1024      <div id="rfc.figure.u.8"></div><pre class="inline"><span id="rfc.iref.g.4"></span>  <a href="#header.content-location" class="smpl">Content-Location</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a>
     1025</pre><p id="rfc.section.3.2.4.p.3">The Content-Location value is not a replacement for the effective Request URI (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.9"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>). It is representation metadata. It has the same syntax and semantics as the header field of the same name defined for MIME
     1026         body parts in <a href="http://tools.ietf.org/html/rfc2557#section-4">Section 4</a> of <a href="#RFC2557" id="rfc.xref.RFC2557.1"><cite title="MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)">[RFC2557]</cite></a>. However, its appearance in an HTTP message has some special implications for HTTP recipients.
     1027      </p>
     1028      <p id="rfc.section.3.2.4.p.4">If Content-Location is included in a response message and its value is the same as the effective request URI, then the response
     1029         payload <em class="bcp14">SHOULD</em> be considered a current representation of that resource. For a GET or HEAD request, this is the same as the default semantics
     1030         when no Content-Location is provided by the server. For a state-changing request like PUT or POST, it implies that the server's
     1031         response contains the new representation of that resource, thereby distinguishing it from representations that might only
     1032         report about the action (e.g., "It worked!"). This allows authoring applications to update their local copies without the
     1033         need for a subsequent GET request.
     1034      </p>
     1035      <p id="rfc.section.3.2.4.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin
     1036         server is informing recipients that this representation has its own, presumably more specific, identifier. For a GET or HEAD
     1037         request, this is an indication that the effective request URI identifies a resource that is subject to content negotiation
     1038         and the selected representation for this response can also be found at the identified URI. For other methods, such a Content-Location
     1039         indicates that this representation contains a report on the action's status and the same report is available (for future access
     1040         with GET) at the given URI. For example, a purchase transaction made via a POST request might include a receipt document as
     1041         the payload of the <a href="#status.200" class="smpl">200 (OK)</a> response; the Content-Location value provides an identifier for retrieving a copy of that same receipt in the future.
     1042      </p>
     1043      <p id="rfc.section.3.2.4.p.6">If Content-Location is included in a request message, then it <em class="bcp14">MAY</em> be interpreted by the origin server as an indication of where the user agent originally obtained the content of the enclosed
     1044         representation (prior to any subsequent modification of the content by that user agent). In other words, the user agent is
     1045         providing the same representation metadata that it received with the original representation. However, such interpretation <em class="bcp14">MUST NOT</em> be used to alter the semantics of the method requested by the client. For example, if a client makes a PUT request on a negotiated
     1046         resource and the origin server accepts that PUT (without redirection), then the new set of values for that resource is expected
     1047         to be consistent with the one representation supplied in that PUT; the Content-Location cannot be used as a form of reverse
     1048         content selection that identifies only one of the negotiated representations to be updated. If the user agent had wanted the
     1049         latter semantics, it would have applied the PUT directly to the Content-Location URI.
     1050      </p>
     1051      <p id="rfc.section.3.2.4.p.7">A Content-Location field received in a request message is transitory information that <em class="bcp14">SHOULD NOT</em> be saved with other representation metadata for use in later responses. The Content-Location's value might be saved for use
     1052         in other contexts, such as within source links or other metadata.
     1053      </p>
     1054      <p id="rfc.section.3.2.4.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used
     1055         to respond to later requests on that Content-Location URI.
     1056      </p>
     1057      <p id="rfc.section.3.2.4.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p>
     1058      <h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="selected.representation" href="#selected.representation">Selected Representation Header Fields</a></h2>
     1059      <p id="rfc.section.3.3.p.1"><span id="rfc.iref.s.1"></span> We use the term "<dfn>selected representation</dfn>" to refer to the the current representation of a target resource that would have been selected in a successful response if
    9421060         the same request had used the method GET and excluded any conditional request header fields.
    9431061      </p>
    944       <p id="rfc.section.3.2.p.4">Additional header fields define metadata about the selected representation, which might differ from the representation included
     1062      <p id="rfc.section.3.3.p.2">Additional header fields define metadata about the selected representation, which might differ from the representation included
    9451063         in the message for responses to some state-changing methods. The following header fields are defined as selected representation
    9461064         metadata:
    … …  
    9661084         </table>
    9671085      </div>
    968       <h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="representation.data" href="#representation.data">Representation Data</a></h2>
    969       <p id="rfc.section.3.3.p.1">The representation body associated with an HTTP message is either provided as the payload body of the message or referred
     1086      <h2 id="rfc.section.3.4"><a href="#rfc.section.3.4">3.4</a>&nbsp;<a id="representation.data" href="#representation.data">Representation Data</a></h2>
     1087      <p id="rfc.section.3.4.p.1">The representation body associated with an HTTP message is either provided as the payload body of the message or referred
    9701088         to by the message semantics and the effective request URI. The representation data is in a format and encoding defined by
    9711089         the representation metadata header fields.
    9721090      </p>
    973       <p id="rfc.section.3.3.p.2">The data type of the representation data is determined via the header fields <a href="#header.content-type" class="smpl">Content-Type</a> and <a href="#header.content-encoding" class="smpl">Content-Encoding</a>. These define a two-layer, ordered encoding model:
    974       </p>
    975       <div id="rfc.figure.u.1"></div><pre class="text">  representation-data := Content-Encoding( Content-Type( bits ) )
    976 </pre><p id="rfc.section.3.3.p.4"> <a href="#header.content-type" class="smpl">Content-Type</a> specifies the media type of the underlying data, which defines both the data format and how that data <em class="bcp14">SHOULD</em> be processed by the recipient (within the scope of the request method semantics). Any HTTP/1.1 message containing a payload
     1091      <p id="rfc.section.3.4.p.2">The data type of the representation data is determined via the header fields <a href="#header.content-type" class="smpl">Content-Type</a> and <a href="#header.content-encoding" class="smpl">Content-Encoding</a>. These define a two-layer, ordered encoding model:
     1092      </p>
     1093      <div id="rfc.figure.u.9"></div><pre class="text">  representation-data := Content-Encoding( Content-Type( bits ) )
     1094</pre><p id="rfc.section.3.4.p.4"> <a href="#header.content-type" class="smpl">Content-Type</a> specifies the media type of the underlying data, which defines both the data format and how that data <em class="bcp14">SHOULD</em> be processed by the recipient (within the scope of the request method semantics). Any HTTP/1.1 message containing a payload
    9771095         body <em class="bcp14">SHOULD</em> include a Content-Type header field defining the media type of the associated representation unless that metadata is unknown
    9781096         to the sender. If the Content-Type header field is not present, it indicates that the sender does not know the media type
    9791097         of the representation; recipients <em class="bcp14">MAY</em> either assume that the media type is "application/octet-stream" (<a href="#RFC2046" id="rfc.xref.RFC2046.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, <a href="http://tools.ietf.org/html/rfc2046#section-4.5.1">Section 4.5.1</a>) or examine the content to determine its type.
    9801098      </p>
    981       <p id="rfc.section.3.3.p.5">In practice, resource owners do not always properly configure their origin server to provide the correct Content-Type for
     1099      <p id="rfc.section.3.4.p.5">In practice, resource owners do not always properly configure their origin server to provide the correct Content-Type for
    9821100         a given representation, with the result that some clients will examine a response body's content and override the specified
    9831101         type. Clients that do so risk drawing incorrect conclusions, which might expose additional security risks (e.g., "privilege
    … …  
    9861104         such "content sniffing" when it is used.
    9871105      </p>
    988       <p id="rfc.section.3.3.p.6"> <a href="#header.content-encoding" class="smpl">Content-Encoding</a> is used to indicate any additional content codings applied to the data, usually for the purpose of data compression, that
     1106      <p id="rfc.section.3.4.p.6"> <a href="#header.content-encoding" class="smpl">Content-Encoding</a> is used to indicate any additional content codings applied to the data, usually for the purpose of data compression, that
    9891107         are a property of the representation. If Content-Encoding is not present, then there is no additional encoding beyond that
    9901108         defined by the <a href="#header.content-type" class="smpl">Content-Type</a> header field.
    9911109      </p>
    992       <h2 id="rfc.section.3.4"><a href="#rfc.section.3.4">3.4</a>&nbsp;<a id="content.negotiation" href="#content.negotiation">Content Negotiation</a></h2>
    993       <p id="rfc.section.3.4.p.1">HTTP responses include a representation which contains information for interpretation, whether by a human user or for further
     1110      <h2 id="rfc.section.3.5"><a href="#rfc.section.3.5">3.5</a>&nbsp;<a id="content.negotiation" href="#content.negotiation">Content Negotiation</a></h2>
     1111      <p id="rfc.section.3.5.p.1">HTTP responses include a representation which contains information for interpretation, whether by a human user or for further
    9941112         processing. Often, the server has different ways of representing the same information; for example, in different formats,
    9951113         languages, or using different character encodings.
    9961114      </p>
    997       <p id="rfc.section.3.4.p.2">HTTP clients and their users might have different or variable capabilities, characteristics or preferences which would influence
     1115      <p id="rfc.section.3.5.p.2">HTTP clients and their users might have different or variable capabilities, characteristics or preferences which would influence
    9981116         which representation, among those available from the server, would be best for the server to deliver. For this reason, HTTP
    9991117         provides mechanisms for "content negotiation" — a process of allowing selection of a representation of a given resource, when
    10001118         more than one is available.
    10011119      </p>
    1002       <p id="rfc.section.3.4.p.3">This specification defines two patterns of content negotiation; "server-driven", where the server selects the representation
     1120      <p id="rfc.section.3.5.p.3">This specification defines two patterns of content negotiation; "server-driven", where the server selects the representation
    10031121         based upon the client's stated preferences, and "agent-driven" negotiation, where the server provides a list of representations
    10041122         for the client to choose from, based upon their metadata. In addition, there are other patterns: some applications use an
    … …  
    10061124         parameters, selects additional resources to invoke. "Transparent Content Negotiation" (<a href="#RFC2295" id="rfc.xref.RFC2295.1"><cite title="Transparent Content Negotiation in HTTP">[RFC2295]</cite></a>) has also been proposed.
    10071125      </p>
    1008       <p id="rfc.section.3.4.p.4">These patterns are all widely used, and have trade-offs in applicability and practicality. In particular, when the number
     1126      <p id="rfc.section.3.5.p.4">These patterns are all widely used, and have trade-offs in applicability and practicality. In particular, when the number
    10091127         of preferences or capabilities to be expressed by a client are large (such as when many different formats are supported by
    10101128         a user-agent), server-driven negotiation becomes unwieldy, and might not be appropriate. Conversely, when the number of representations
    10111129         to choose from is very large, agent-driven negotiation might not be appropriate.
    10121130      </p>
    1013       <p id="rfc.section.3.4.p.5">Note that, in all cases, the supplier of representations has the responsibility for determining which representations might
     1131      <p id="rfc.section.3.5.p.5">Note that, in all cases, the supplier of representations has the responsibility for determining which representations might
    10141132         be considered to be the "same information".
    10151133      </p>
    1016       <h3 id="rfc.section.3.4.1"><a href="#rfc.section.3.4.1">3.4.1</a>&nbsp;<a id="server-driven.negotiation" href="#server-driven.negotiation">Server-driven Negotiation</a></h3>
    1017       <p id="rfc.section.3.4.1.p.1">If the selection of the best representation for a response is made by an algorithm located at the server, it is called server-driven
     1134      <h3 id="rfc.section.3.5.1"><a href="#rfc.section.3.5.1">3.5.1</a>&nbsp;<a id="server-driven.negotiation" href="#server-driven.negotiation">Server-driven Negotiation</a></h3>
     1135      <p id="rfc.section.3.5.1.p.1">If the selection of the best representation for a response is made by an algorithm located at the server, it is called server-driven
    10181136         negotiation. Selection is based on the available representations of the response (the dimensions over which it can vary; e.g.,
    10191137         language, content-coding, etc.) and the contents of particular header fields in the request message or on other information
    10201138         pertaining to the request (such as the network address of the client).
    10211139      </p>
    1022       <p id="rfc.section.3.4.1.p.2">Server-driven negotiation is advantageous when the algorithm for selecting from among the available representations is difficult
     1140      <p id="rfc.section.3.5.1.p.2">Server-driven negotiation is advantageous when the algorithm for selecting from among the available representations is difficult
    10231141         to describe to the user agent, or when the server desires to send its "best guess" to the client along with the first response
    10241142         (hoping to avoid the round-trip delay of a subsequent request if the "best guess" is good enough for the user). In order to
    10251143         improve the server's guess, the user agent <em class="bcp14">MAY</em> include request header fields (<a href="#header.accept" class="smpl">Accept</a>, <a href="#header.accept-language" class="smpl">Accept-Language</a>, <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a>, etc.) which describe its preferences for such a response.
    10261144      </p>
    1027       <p id="rfc.section.3.4.1.p.3">Server-driven negotiation has disadvantages: </p>
     1145      <p id="rfc.section.3.5.1.p.3">Server-driven negotiation has disadvantages: </p>
    10281146      <ol>
    10291147         <li>It is impossible for the server to accurately determine what might be "best" for any given user, since that would require
    … …  
    10371155         <li>It might limit a public cache's ability to use the same response for multiple user's requests.</li>
    10381156      </ol>
    1039       <p id="rfc.section.3.4.1.p.4">Server-driven negotiation allows the user agent to specify its preferences, but it cannot expect responses to always honor
     1157      <p id="rfc.section.3.5.1.p.4">Server-driven negotiation allows the user agent to specify its preferences, but it cannot expect responses to always honor
    10401158         them. For example, the origin server might not implement server-driven negotiation, or it might decide that sending a response
    10411159         that doesn't conform to them is better than sending a <a href="#status.406" class="smpl">406
    10421160            (Not Acceptable)</a> response.
    10431161      </p>
    1044       <p id="rfc.section.3.4.1.p.5">HTTP/1.1 includes the following header fields for enabling server-driven negotiation through description of user agent capabilities
    1045          and user preferences: <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.1" title="Accept">Section&nbsp;10.1</a>), <a href="#header.accept-charset" class="smpl">Accept-Charset</a> (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.1" title="Accept-Charset">Section&nbsp;10.2</a>), <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.1" title="Accept-Encoding">Section&nbsp;10.3</a>), <a href="#header.accept-language" class="smpl">Accept-Language</a> (<a href="#header.accept-language" id="rfc.xref.header.accept-language.1" title="Accept-Language">Section&nbsp;10.4</a>), and <a href="#header.user-agent" class="smpl">User-Agent</a> (<a href="#header.user-agent" id="rfc.xref.header.user-agent.1" title="User-Agent">Section&nbsp;10.18</a>). However, an origin server is not limited to these dimensions and <em class="bcp14">MAY</em> vary the response based on any aspect of the request, including aspects of the connection (e.g., IP address) or information
     1162      <p id="rfc.section.3.5.1.p.5">HTTP/1.1 includes the following header fields for enabling server-driven negotiation through description of user agent capabilities
     1163         and user preferences: <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.1" title="Accept">Section&nbsp;6.3.2</a>), <a href="#header.accept-charset" class="smpl">Accept-Charset</a> (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.1" title="Accept-Charset">Section&nbsp;6.3.3</a>), <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.1" title="Accept-Encoding">Section&nbsp;6.3.4</a>), <a href="#header.accept-language" class="smpl">Accept-Language</a> (<a href="#header.accept-language" id="rfc.xref.header.accept-language.1" title="Accept-Language">Section&nbsp;6.3.5</a>), and <a href="#header.user-agent" class="smpl">User-Agent</a> (<a href="#header.user-agent" id="rfc.xref.header.user-agent.1" title="User-Agent">Section&nbsp;6.5.3</a>). However, an origin server is not limited to these dimensions and <em class="bcp14">MAY</em> vary the response based on any aspect of the request, including aspects of the connection (e.g., IP address) or information
    10461164         within extension header fields not defined by this specification.
    10471165      </p>
    1048       <div class="note" id="rfc.section.3.4.1.p.6">
     1166      <div class="note" id="rfc.section.3.5.1.p.6">
    10491167         <p> <b>Note:</b> In practice, <a href="#header.user-agent" class="smpl">User-Agent</a> based negotiation is fragile, because new clients might not be recognized.
    10501168         </p>
    10511169      </div>
    1052       <p id="rfc.section.3.4.1.p.7">The <a href="p6-cache.html#header.vary" class="smpl">Vary</a> header field (<a href="p6-cache.html#header.vary" title="Vary">Section 7.5</a> of <a href="#Part6" id="rfc.xref.Part6.2"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) can be used to express the parameters the server uses to select a representation that is subject to server-driven negotiation.
    1053       </p>
    1054       <h3 id="rfc.section.3.4.2"><a href="#rfc.section.3.4.2">3.4.2</a>&nbsp;<a id="agent-driven.negotiation" href="#agent-driven.negotiation">Agent-driven Negotiation</a></h3>
    1055       <p id="rfc.section.3.4.2.p.1">With agent-driven negotiation, selection of the best representation for a response is performed by the user agent after receiving
     1170      <p id="rfc.section.3.5.1.p.7">The <a href="p6-cache.html#header.vary" class="smpl">Vary</a> header field (<a href="p6-cache.html#header.vary" title="Vary">Section 7.5</a> of <a href="#Part6" id="rfc.xref.Part6.2"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) can be used to express the parameters the server uses to select a representation that is subject to server-driven negotiation.
     1171      </p>
     1172      <h3 id="rfc.section.3.5.2"><a href="#rfc.section.3.5.2">3.5.2</a>&nbsp;<a id="agent-driven.negotiation" href="#agent-driven.negotiation">Agent-driven Negotiation</a></h3>
     1173      <p id="rfc.section.3.5.2.p.1">With agent-driven negotiation, selection of the best representation for a response is performed by the user agent after receiving
    10561174         an initial response from the origin server. Selection is based on a list of the available representations of the response
    10571175         included within the header fields or body of the initial response, with each representation identified by its own URI. Selection
    … …  
    10591177         user selecting from a generated (possibly hypertext) menu.
    10601178      </p>
    1061       <p id="rfc.section.3.4.2.p.2">Agent-driven negotiation is advantageous when the response would vary over commonly-used dimensions (such as type, language,
     1179      <p id="rfc.section.3.5.2.p.2">Agent-driven negotiation is advantageous when the response would vary over commonly-used dimensions (such as type, language,
    10621180         or encoding), when the origin server is unable to determine a user agent's capabilities from examining the request, and generally
    10631181         when public caches are used to distribute server load and reduce network usage.
    10641182      </p>
    1065       <p id="rfc.section.3.4.2.p.3">Agent-driven negotiation suffers from the disadvantage of needing a second request to obtain the best alternate representation.
     1183      <p id="rfc.section.3.5.2.p.3">Agent-driven negotiation suffers from the disadvantage of needing a second request to obtain the best alternate representation.
    10661184         This second request is only efficient when caching is used. In addition, this specification does not define any mechanism
    10671185         for supporting automatic selection, though it also does not prevent any such mechanism from being developed as an extension
    10681186         and used within HTTP/1.1.
    10691187      </p>
    1070       <p id="rfc.section.3.4.2.p.4">This specification defines the <a href="#status.300" class="smpl">300 (Multiple Choices)</a> and <a href="#status.406" class="smpl">406 (Not Acceptable)</a> status codes for enabling agent-driven negotiation when the server is unwilling or unable to provide a varying response using
     1188      <p id="rfc.section.3.5.2.p.4">This specification defines the <a href="#status.300" class="smpl">300 (Multiple Choices)</a> and <a href="#status.406" class="smpl">406 (Not Acceptable)</a> status codes for enabling agent-driven negotiation when the server is unwilling or unable to provide a varying response using
    10711189         server-driven negotiation.
    1072       </p>
    1073       <h3 id="rfc.section.3.4.3"><a href="#rfc.section.3.4.3">3.4.3</a>&nbsp;<a id="quality.values" href="#quality.values">Quality Values</a></h3>
    1074       <p id="rfc.section.3.4.3.p.1">Many of the request header fields for server-driven content negotiation use a common parameter, named "q", to assign a relative
    1075          "weight" to the preference for that associated kind of content. This weight is referred to as a "quality value" (or "qvalue")
    1076          because the same parameter name is often used within server configurations to assign a weight to the relative quality of the
    1077          various representations that can be selected for a resource.
    1078       </p>
    1079       <p id="rfc.section.3.4.3.p.2">The weight is normalized to a real number in the range 0 through 1, where 0.001 is the least preferred and 1 is the most preferred;
    1080          a value of 0 means "not acceptable". If no "q" parameter is present, the default weight is 1.
    1081       </p>
    1082       <div id="rfc.figure.u.2"></div><pre class="inline"><span id="rfc.iref.g.1"></span><span id="rfc.iref.g.2"></span>  <a href="#quality.values" class="smpl">weight</a> = <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> "q=" <a href="#quality.values" class="smpl">qvalue</a>
    1083   <a href="#quality.values" class="smpl">qvalue</a> = ( "0" [ "." 0*3<a href="#imported.abnf" class="smpl">DIGIT</a> ] )
    1084          / ( "1" [ "." 0*3("0") ] )
    1085 </pre><p id="rfc.section.3.4.3.p.4">A sender of qvalue <em class="bcp14">MUST NOT</em> generate more than three digits after the decimal point. User configuration of these values ought to be limited in the same
    1086          fashion.
    10871190      </p>
    10881191      <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="payload" href="#payload">Payload</a></h1>
    … …  
    11111214               <tr>
    11121215                  <td class="left">Content-Length</td>
    1113                   <td class="left"><a href="p1-messaging.html#header.content-length" title="Content-Length">Section 3.3.2</a> of <a href="#Part1" id="rfc.xref.Part1.9"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a></td>
     1216                  <td class="left"><a href="p1-messaging.html#header.content-length" title="Content-Length">Section 3.3.2</a> of <a href="#Part1" id="rfc.xref.Part1.10"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a></td>
    11141217               </tr>
    11151218               <tr>
    … …  
    11211224      </div>
    11221225      <h2 id="rfc.section.4.2"><a href="#rfc.section.4.2">4.2</a>&nbsp;<a id="payload.body" href="#payload.body">Payload Body</a></h2>
    1123       <p id="rfc.section.4.2.p.1">A payload body is only present in a message when a message body is present, as described in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.10"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>. The payload body is obtained from the message body by decoding any <a href="p1-messaging.html#header.transfer-encoding" class="smpl">Transfer-Encoding</a> that might have been applied to ensure safe and proper transfer of the message.
     1226      <p id="rfc.section.4.2.p.1">A payload body is only present in a message when a message body is present, as described in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.11"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>. The payload body is obtained from the message body by decoding any <a href="p1-messaging.html#header.transfer-encoding" class="smpl">Transfer-Encoding</a> that might have been applied to ensure safe and proper transfer of the message.
    11241227      </p>
    11251228      <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="methods" href="#methods">Request Methods</a></h1>
    … …  
    11281231         this request and what is expected by the client as a successful result. The request semantics <em class="bcp14">MAY</em> be further specialized by the semantics of some header fields when present in a request (<a href="#request.header.fields" title="Request Header Fields">Section&nbsp;6</a>) if those additional semantics do not conflict with the method.
    11291232      </p>
    1130       <div id="rfc.figure.u.3"></div><pre class="inline"><span id="rfc.iref.g.3"></span>  <a href="#method.overview" class="smpl">method</a> = <a href="#imported.abnf" class="smpl">token</a>
     1233      <div id="rfc.figure.u.10"></div><pre class="inline"><span id="rfc.iref.g.5"></span>  <a href="#method.overview" class="smpl">method</a> = <a href="#imported.abnf" class="smpl">token</a>
    11311234</pre><p id="rfc.section.5.1.p.3">HTTP was originally designed to be usable as an interface to distributed object systems. The request method was envisioned
    11321235         as applying semantics to a target resource in much the same way as invoking a defined method on an identified object would
    … …  
    11981301      </p>
    11991302      <p id="rfc.section.5.1.p.7">Additional methods <em class="bcp14">MAY</em> be used in HTTP; many have already been standardized outside the scope of this specification and registered within the HTTP
    1200          Method Registry maintained by IANA, as defined in <a href="#method.registry" title="Method Registry">Section&nbsp;11.1</a>.
    1201       </p>
    1202       <p id="rfc.section.5.1.p.8">The set of methods allowed by a target resource can be listed in an <a href="#header.allow" class="smpl">Allow</a> header field (<a href="#header.allow" id="rfc.xref.header.allow.1" title="Allow">Section&nbsp;10.5</a>). However, the set of allowed methods can change dynamically. When a request message is received that is unrecognized or
     1303         Method Registry maintained by IANA, as defined in <a href="#method.registry" title="Method Registry">Section&nbsp;10.1</a>.
     1304      </p>
     1305      <p id="rfc.section.5.1.p.8">The set of methods allowed by a target resource can be listed in an <a href="#header.allow" class="smpl">Allow</a> header field (<a href="#header.allow" id="rfc.xref.header.allow.1" title="Allow">Section&nbsp;8.4.1</a>). However, the set of allowed methods can change dynamically. When a request message is received that is unrecognized or
    12031306         not implemented by an origin server, the origin server <em class="bcp14">SHOULD</em> respond with the <a href="#status.501" class="smpl">501 (Not Implemented)</a> status code. When a request message is received that is known by an origin server but not allowed for the target resource,
    12041307         the origin server <em class="bcp14">SHOULD</em> respond with the <a href="#status.405" class="smpl">405 (Method Not Allowed)</a> status code.
    … …  
    12481351         repeated failures would indicate a problem within the server.
    12491352      </p>
    1250       <div id="rfc.iref.c.2"></div>
     1353      <div id="rfc.iref.c.6"></div>
    12511354      <h3 id="rfc.section.5.2.3"><a href="#rfc.section.5.2.3">5.2.3</a>&nbsp;<a id="cacheable.methods" href="#cacheable.methods">Cacheable Methods</a></h3>
    12521355      <p id="rfc.section.5.2.3.p.1">Request methods are considered "<dfn id="cacheable">cacheable</dfn>" if it is possible and useful to answer a current client request with a stored response from a prior request. GET and HEAD
    … …  
    12571360      <h2 id="rfc.section.5.3"><a href="#rfc.section.5.3">5.3</a>&nbsp;<a id="method.definitions" href="#method.definitions">Method Definitions</a></h2>
    12581361      <h3 id="rfc.section.5.3.1"><a href="#rfc.section.5.3.1">5.3.1</a>&nbsp;<a id="GET" href="#GET">GET</a></h3>
    1259       <div id="rfc.iref.g.4"></div>
     1362      <div id="rfc.iref.g.6"></div>
    12601363      <div id="rfc.iref.m.1"></div>
    12611364      <p id="rfc.section.5.3.1.p.1">The GET method requests transfer of a current representation of the target resource.</p>
    … …  
    12751378      <p id="rfc.section.5.3.1.p.6">The response to a GET request is cacheable and <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD requests (see <a href="#Part6" id="rfc.xref.Part6.4"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>).
    12761379      </p>
    1277       <p id="rfc.section.5.3.1.p.7">See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section&nbsp;12.2</a> for security considerations when used for forms.
     1380      <p id="rfc.section.5.3.1.p.7">See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section&nbsp;11.2</a> for security considerations when used for forms.
    12781381      </p>
    12791382      <h3 id="rfc.section.5.3.2"><a href="#rfc.section.5.3.2">5.3.2</a>&nbsp;<a id="HEAD" href="#HEAD">HEAD</a></h3>
    1280       <div id="rfc.iref.h.1"></div>
     1383      <div id="rfc.iref.h.5"></div>
    12811384      <div id="rfc.iref.m.2"></div>
    12821385      <p id="rfc.section.5.3.2.p.1">The HEAD method is identical to GET except that the server <em class="bcp14">MUST NOT</em> return a message body in the response. The metadata contained in the HTTP header fields in response to a HEAD request <em class="bcp14">SHOULD</em> be identical to the information sent in response to a GET request. This method can be used for obtaining metadata about the
    … …  
    13071410         the result.
    13081411      </p>
    1309       <p id="rfc.section.5.3.3.p.4">If a resource has been created on the origin server, the response <em class="bcp14">SHOULD</em> be <a href="#status.201" class="smpl">201 (Created)</a> and contain a representation which describes the status of the request and refers to the new resource, and a <a href="#header.location" class="smpl">Location</a> header field (see <a href="#header.location" id="rfc.xref.header.location.1" title="Location">Section&nbsp;10.13</a>).
    1310       </p>
    1311       <p id="rfc.section.5.3.3.p.5">Responses to POST requests are only cacheable when they include explicit freshness information (see <a href="p6-cache.html#calculating.freshness.lifetime" title="Calculating Freshness Lifetime">Section 4.1.1</a> of <a href="#Part6" id="rfc.xref.Part6.6"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). A cached POST response with a <a href="#header.content-location" class="smpl">Content-Location</a> header field (see <a href="#header.content-location" id="rfc.xref.header.content-location.2" title="Content-Location">Section&nbsp;10.8</a>) whose value is the effective Request URI <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD requests.
     1412      <p id="rfc.section.5.3.3.p.4">If a resource has been created on the origin server, the response <em class="bcp14">SHOULD</em> be <a href="#status.201" class="smpl">201 (Created)</a> and contain a representation which describes the status of the request and refers to the new resource, and a <a href="#header.location" class="smpl">Location</a> header field (see <a href="#header.location" id="rfc.xref.header.location.1" title="Location">Section&nbsp;8.1.1</a>).
     1413      </p>
     1414      <p id="rfc.section.5.3.3.p.5">Responses to POST requests are only cacheable when they include explicit freshness information (see <a href="p6-cache.html#calculating.freshness.lifetime" title="Calculating Freshness Lifetime">Section 4.1.1</a> of <a href="#Part6" id="rfc.xref.Part6.6"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>). A cached POST response with a <a href="#header.content-location" class="smpl">Content-Location</a> header field (see <a href="#header.content-location" id="rfc.xref.header.content-location.2" title="Content-Location">Section&nbsp;3.2.4</a>) whose value is the effective Request URI <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD requests.
    13121415      </p>
    13131416      <p id="rfc.section.5.3.3.p.6">Note that POST caching is not widely implemented. However, the <a href="#status.303" class="smpl">303 (See Other)</a> response can be used to direct the user agent to retrieve a cacheable representation of the resource.
    … …  
    13931496         for the effective request URI, those stored responses will be invalidated (see <a href="p6-cache.html#invalidation.after.updates.or.deletions" title="Request Methods that Invalidate">Section 6</a> of <a href="#Part6" id="rfc.xref.Part6.8"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>).
    13941497      </p>
    1395       <div id="rfc.iref.c.3"></div>
     1498      <div id="rfc.iref.c.7"></div>
    13961499      <div id="rfc.iref.m.6"></div>
    13971500      <h3 id="rfc.section.5.3.6"><a href="#rfc.section.5.3.6">5.3.6</a>&nbsp;<a id="CONNECT" href="#CONNECT">CONNECT</a></h3>
    … …  
    13991502         its behavior to blind forwarding of packets until the connection is closed.
    14001503      </p>
    1401       <p id="rfc.section.5.3.6.p.2">When using CONNECT, the request-target <em class="bcp14">MUST</em> use the authority form (<a href="p1-messaging.html#request-target" title="Request Target">Section 5.3</a> of <a href="#Part1" id="rfc.xref.Part1.11"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>); i.e., the request-target consists of only the host name and port number of the tunnel destination, separated by a colon.
     1504      <p id="rfc.section.5.3.6.p.2">When using CONNECT, the request-target <em class="bcp14">MUST</em> use the authority form (<a href="p1-messaging.html#request-target" title="Request Target">Section 5.3</a> of <a href="#Part1" id="rfc.xref.Part1.12"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>); i.e., the request-target consists of only the host name and port number of the tunnel destination, separated by a colon.
    14021505         For example,
    14031506      </p>
    1404       <div id="rfc.figure.u.4"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
     1507      <div id="rfc.figure.u.11"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
    14051508Host: server.example.com:80
    14061509
    … …  
    14151518      </p>
    14161519      <p id="rfc.section.5.3.6.p.7">Proxy authentication might be used to establish the authority to create a tunnel:</p>
    1417       <div id="rfc.figure.u.5"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
     1520      <div id="rfc.figure.u.12"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
    14181521Host: server.example.com:80
    14191522Proxy-Authorization: basic aGVsbG86d29ybGQ=
    … …  
    14451548         body to make more detailed queries on the server.
    14461549      </p>
    1447       <p id="rfc.section.5.3.7.p.4">If the request-target (<a href="p1-messaging.html#request-target" title="Request Target">Section 5.3</a> of <a href="#Part1" id="rfc.xref.Part1.12"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) is an asterisk ("*"), the OPTIONS request is intended to apply to the server in general rather than to a specific resource.
     1550      <p id="rfc.section.5.3.7.p.4">If the request-target (<a href="p1-messaging.html#request-target" title="Request Target">Section 5.3</a> of <a href="#Part1" id="rfc.xref.Part1.13"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) is an asterisk ("*"), the OPTIONS request is intended to apply to the server in general rather than to a specific resource.
    14481551         Since a server's communication options typically depend on the resource, the "*" request is only useful as a "ping" or "no-op"
    14491552         type of method; it does nothing beyond allowing the client to test the capabilities of the server. For example, this can be
    … …  
    14561559         but might be defined by future extensions to HTTP. Content negotiation <em class="bcp14">MAY</em> be used to select the appropriate response format. If no response body is included, the response <em class="bcp14">MUST</em> include a <a href="p1-messaging.html#header.content-length" class="smpl">Content-Length</a> field with a field-value of "0".
    14571560      </p>
    1458       <p id="rfc.section.5.3.7.p.7">The <a href="#header.max-forwards" class="smpl">Max-Forwards</a> header field <em class="bcp14">MAY</em> be used to target a specific proxy in the request chain (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.1" title="Max-Forwards">Section&nbsp;10.14</a>). If no Max-Forwards field is present in the request, then the forwarded request <em class="bcp14">MUST NOT</em> include a Max-Forwards field.
     1561      <p id="rfc.section.5.3.7.p.7">The <a href="#header.max-forwards" class="smpl">Max-Forwards</a> header field <em class="bcp14">MAY</em> be used to target a specific proxy in the request chain (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.1" title="Max-Forwards">Section&nbsp;6.1.1</a>). If no Max-Forwards field is present in the request, then the forwarded request <em class="bcp14">MUST NOT</em> include a Max-Forwards field.
    14591562      </p>
    14601563      <h3 id="rfc.section.5.3.8"><a href="#rfc.section.5.3.8">5.3.8</a>&nbsp;<a id="TRACE" href="#TRACE">TRACE</a></h3>
    14611564      <div id="rfc.iref.t.1"></div>
    14621565      <div id="rfc.iref.m.8"></div>
    1463       <p id="rfc.section.5.3.8.p.1">The TRACE method requests a remote, application-layer loop-back of the request message. The final recipient of the request <em class="bcp14">SHOULD</em> reflect the message received back to the client as the message body of a <a href="#status.200" class="smpl">200 (OK)</a> response. The final recipient is either the origin server or the first proxy to receive a <a href="#header.max-forwards" class="smpl">Max-Forwards</a> value of zero (0) in the request (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.2" title="Max-Forwards">Section&nbsp;10.14</a>). A TRACE request <em class="bcp14">MUST NOT</em> include a message body.
     1566      <p id="rfc.section.5.3.8.p.1">The TRACE method requests a remote, application-layer loop-back of the request message. The final recipient of the request <em class="bcp14">SHOULD</em> reflect the message received back to the client as the message body of a <a href="#status.200" class="smpl">200 (OK)</a> response. The final recipient is either the origin server or the first proxy to receive a <a href="#header.max-forwards" class="smpl">Max-Forwards</a> value of zero (0) in the request (see <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.2" title="Max-Forwards">Section&nbsp;6.1.1</a>). A TRACE request <em class="bcp14">MUST NOT</em> include a message body.
    14641567      </p>
    14651568      <p id="rfc.section.5.3.8.p.2">TRACE allows the client to see what is being received at the other end of the request chain and use that data for testing
    1466          or diagnostic information. The value of the <a href="p1-messaging.html#header.via" class="smpl">Via</a> header field (<a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.13"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) is of particular interest, since it acts as a trace of the request chain. Use of the <a href="#header.max-forwards" class="smpl">Max-Forwards</a> header field allows the client to limit the length of the request chain, which is useful for testing a chain of proxies forwarding
     1569         or diagnostic information. The value of the <a href="p1-messaging.html#header.via" class="smpl">Via</a> header field (<a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.14"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) is of particular interest, since it acts as a trace of the request chain. Use of the <a href="#header.max-forwards" class="smpl">Max-Forwards</a> header field allows the client to limit the length of the request chain, which is useful for testing a chain of proxies forwarding
    14671570         messages in an infinite loop.
    14681571      </p>
    1469       <p id="rfc.section.5.3.8.p.3">If the request is valid, the response <em class="bcp14">SHOULD</em> have a <a href="#header.content-type" class="smpl">Content-Type</a> of "message/http" (see <a href="p1-messaging.html#internet.media.type.message.http" title="Internet Media Type message/http">Section 7.3.1</a> of <a href="#Part1" id="rfc.xref.Part1.14"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) and contain a message body that encloses a copy of the entire request message. Responses to the TRACE method are not cacheable.
     1572      <p id="rfc.section.5.3.8.p.3">If the request is valid, the response <em class="bcp14">SHOULD</em> have a <a href="#header.content-type" class="smpl">Content-Type</a> of "message/http" (see <a href="p1-messaging.html#internet.media.type.message.http" title="Internet Media Type message/http">Section 7.3.1</a> of <a href="#Part1" id="rfc.xref.Part1.15"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) and contain a message body that encloses a copy of the entire request message. Responses to the TRACE method are not cacheable.
    14701573      </p>
    14711574      <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a id="request.header.fields" href="#request.header.fields">Request Header Fields</a></h1>
    … …  
    14881591               <tr>
    14891592                  <td class="left">Host</td>
    1490                   <td class="left"><a href="p1-messaging.html#header.host" title="Host">Section 5.4</a> of <a href="#Part1" id="rfc.xref.Part1.15"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a></td>
     1593                  <td class="left"><a href="p1-messaging.html#header.host" title="Host">Section 5.4</a> of <a href="#Part1" id="rfc.xref.Part1.16"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a></td>
    14911594               </tr>
    14921595               <tr>
    14931596                  <td class="left">Max-Forwards</td>
    1494                   <td class="left"><a href="#header.max-forwards" id="rfc.xref.header.max-forwards.3" title="Max-Forwards">Section&nbsp;10.14</a></td>
     1597                  <td class="left"><a href="#header.max-forwards" id="rfc.xref.header.max-forwards.3" title="Max-Forwards">Section&nbsp;6.1.1</a></td>
    14951598               </tr>
    14961599               <tr>
    14971600                  <td class="left">Expect</td>
    1498                   <td class="left"><a href="#header.expect" id="rfc.xref.header.expect.1" title="Expect">Section&nbsp;10.11</a></td>
     1601                  <td class="left"><a href="#header.expect" id="rfc.xref.header.expect.1" title="Expect">Section&nbsp;6.1.2</a></td>
    14991602               </tr>
    15001603               <tr>
    … …  
    15051608         </table>
    15061609      </div>
     1610      <div id="rfc.iref.m.9"></div>
     1611      <div id="rfc.iref.h.6"></div>
     1612      <h3 id="rfc.section.6.1.1"><a href="#rfc.section.6.1.1">6.1.1</a>&nbsp;<a id="header.max-forwards" href="#header.max-forwards">Max-Forwards</a></h3>
     1613      <p id="rfc.section.6.1.1.p.1">The "Max-Forwards" header field provides a mechanism with the TRACE (<a href="#TRACE" id="rfc.xref.TRACE.2" title="TRACE">Section&nbsp;5.3.8</a>) and OPTIONS (<a href="#OPTIONS" id="rfc.xref.OPTIONS.2" title="OPTIONS">Section&nbsp;5.3.7</a>) methods to limit the number of times that the request is forwarded by proxies. This can be useful when the client is attempting
     1614         to trace a request which appears to be failing or looping mid-chain.
     1615      </p>
     1616      <div id="rfc.figure.u.13"></div><pre class="inline"><span id="rfc.iref.g.7"></span>  <a href="#header.max-forwards" class="smpl">Max-Forwards</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
     1617</pre><p id="rfc.section.6.1.1.p.3">The Max-Forwards value is a decimal integer indicating the remaining number of times this request message can be forwarded.</p>
     1618      <p id="rfc.section.6.1.1.p.4">Each recipient of a TRACE or OPTIONS request containing a Max-Forwards header field <em class="bcp14">MUST</em> check and update its value prior to forwarding the request. If the received value is zero (0), the recipient <em class="bcp14">MUST NOT</em> forward the request; instead, it <em class="bcp14">MUST</em> respond as the final recipient. If the received Max-Forwards value is greater than zero, then the forwarded message <em class="bcp14">MUST</em> contain an updated Max-Forwards field with a value decremented by one (1).
     1619      </p>
     1620      <p id="rfc.section.6.1.1.p.5">The Max-Forwards header field <em class="bcp14">MAY</em> be ignored for all other request methods.
     1621      </p>
     1622      <div id="rfc.iref.e.1"></div>
     1623      <div id="rfc.iref.h.7"></div>
     1624      <h3 id="rfc.section.6.1.2"><a href="#rfc.section.6.1.2">6.1.2</a>&nbsp;<a id="header.expect" href="#header.expect">Expect</a></h3>
     1625      <p id="rfc.section.6.1.2.p.1">The "Expect" header field is used to indicate that particular server behaviors are required by the client.</p>
     1626      <div id="rfc.figure.u.14"></div><pre class="inline"><span id="rfc.iref.g.8"></span><span id="rfc.iref.g.9"></span><span id="rfc.iref.g.10"></span><span id="rfc.iref.g.11"></span><span id="rfc.iref.g.12"></span>  <a href="#header.expect" class="smpl">Expect</a>       = 1#<a href="#header.expect" class="smpl">expectation</a>
     1627 
     1628  <a href="#header.expect" class="smpl">expectation</a>  = <a href="#header.expect" class="smpl">expect-name</a> [ <a href="#imported.abnf" class="smpl">BWS</a> "=" <a href="#imported.abnf" class="smpl">BWS</a> <a href="#header.expect" class="smpl">expect-value</a> ]
     1629                             *( <a href="#imported.abnf" class="smpl">OWS</a> ";" [ <a href="#imported.abnf" class="smpl">OWS</a> <a href="#header.expect" class="smpl">expect-param</a> ] )
     1630  <a href="#header.expect" class="smpl">expect-param</a> = <a href="#header.expect" class="smpl">expect-name</a> [ <a href="#imported.abnf" class="smpl">BWS</a> "=" <a href="#imported.abnf" class="smpl">BWS</a> <a href="#header.expect" class="smpl">expect-value</a> ]
     1631 
     1632  <a href="#header.expect" class="smpl">expect-name</a>  = <a href="#imported.abnf" class="smpl">token</a>
     1633  <a href="#header.expect" class="smpl">expect-value</a> = <a href="#imported.abnf" class="smpl">token</a> / <a href="#imported.abnf" class="smpl">quoted-string</a>
     1634</pre><p id="rfc.section.6.1.2.p.3">If all received Expect header field(s) are syntactically valid but contain an expectation that the recipient does not understand
     1635         or cannot comply with, the recipient <em class="bcp14">MUST</em> respond with a <a href="#status.417" class="smpl">417 (Expectation Failed)</a> status code. A recipient of a syntactically invalid Expectation header field <em class="bcp14">MUST</em> respond with a <a href="#status.4xx" class="smpl">4xx</a> status code other than 417.
     1636      </p>
     1637      <p id="rfc.section.6.1.2.p.4">The only expectation defined by this specification is:</p>
     1638      <p id="rfc.section.6.1.2.p.5"><span id="rfc.iref.46"></span><span id="rfc.iref.e.2"></span> 100-continue
     1639      </p>
     1640      <ul class="empty">
     1641         <li>The "100-continue" expectation is defined <a href="p1-messaging.html#use.of.the.100.status" title="Use of the 100 (Continue) Status">Section 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.17"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>. It does not support any expect-params.
     1642         </li>
     1643      </ul>
     1644      <p id="rfc.section.6.1.2.p.6">Comparison is case-insensitive for names (expect-name), and case-sensitive for values (expect-value).</p>
     1645      <p id="rfc.section.6.1.2.p.7">The Expect mechanism is hop-by-hop: the above requirements apply to any server, including proxies. However, the Expect header
     1646         field itself is end-to-end; it <em class="bcp14">MUST</em> be forwarded if the request is forwarded.
     1647      </p>
     1648      <p id="rfc.section.6.1.2.p.8">Many older HTTP/1.0 and HTTP/1.1 applications do not understand the Expect header field.</p>
    15071649      <h2 id="rfc.section.6.2"><a href="#rfc.section.6.2">6.2</a>&nbsp;<a id="request.conditionals" href="#request.conditionals">Conditionals</a></h2>
    15081650      <p id="rfc.section.6.2.p.1">Conditionals are request header fields that indicate a precondition to be tested before applying the method semantics to the
    … …  
    15541696               <tr>
    15551697                  <td class="left">Accept</td>
    1556                   <td class="left"><a href="#header.accept" id="rfc.xref.header.accept.2" title="Accept">Section&nbsp;10.1</a></td>
     1698                  <td class="left"><a href="#header.accept" id="rfc.xref.header.accept.2" title="Accept">Section&nbsp;6.3.2</a></td>
    15571699               </tr>
    15581700               <tr>
    15591701                  <td class="left">Accept-Charset</td>
    1560                   <td class="left"><a href="#header.accept-charset" id="rfc.xref.header.accept-charset.2" title="Accept-Charset">Section&nbsp;10.2</a></td>
     1702                  <td class="left"><a href="#header.accept-charset" id="rfc.xref.header.accept-charset.2" title="Accept-Charset">Section&nbsp;6.3.3</a></td>
    15611703               </tr>
    15621704               <tr>
    15631705                  <td class="left">Accept-Encoding</td>
    1564                   <td class="left"><a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.2" title="Accept-Encoding">Section&nbsp;10.3</a></td>
     1706                  <td class="left"><a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.2" title="Accept-Encoding">Section&nbsp;6.3.4</a></td>
    15651707               </tr>
    15661708               <tr>
    15671709                  <td class="left">Accept-Language</td>
    1568                   <td class="left"><a href="#header.accept-language" id="rfc.xref.header.accept-language.2" title="Accept-Language">Section&nbsp;10.4</a></td>
     1710                  <td class="left"><a href="#header.accept-language" id="rfc.xref.header.accept-language.2" title="Accept-Language">Section&nbsp;6.3.5</a></td>
    15691711               </tr>
    15701712            </tbody>
    15711713         </table>
    15721714      </div>
     1715      <h3 id="rfc.section.6.3.1"><a href="#rfc.section.6.3.1">6.3.1</a>&nbsp;<a id="quality.values" href="#quality.values">Quality Values</a></h3>
     1716      <p id="rfc.section.6.3.1.p.1">Many of the request header fields for server-driven content negotiation use a common parameter, named "q", to assign a relative
     1717         "weight" to the preference for that associated kind of content. This weight is referred to as a "quality value" (or "qvalue")
     1718         because the same parameter name is often used within server configurations to assign a weight to the relative quality of the
     1719         various representations that can be selected for a resource.
     1720      </p>
     1721      <p id="rfc.section.6.3.1.p.2">The weight is normalized to a real number in the range 0 through 1, where 0.001 is the least preferred and 1 is the most preferred;
     1722         a value of 0 means "not acceptable". If no "q" parameter is present, the default weight is 1.
     1723      </p>
     1724      <div id="rfc.figure.u.15"></div><pre class="inline"><span id="rfc.iref.g.13"></span><span id="rfc.iref.g.14"></span>  <a href="#quality.values" class="smpl">weight</a> = <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> "q=" <a href="#quality.values" class="smpl">qvalue</a>
     1725  <a href="#quality.values" class="smpl">qvalue</a> = ( "0" [ "." 0*3<a href="#imported.abnf" class="smpl">DIGIT</a> ] )
     1726         / ( "1" [ "." 0*3("0") ] )
     1727</pre><p id="rfc.section.6.3.1.p.4">A sender of qvalue <em class="bcp14">MUST NOT</em> generate more than three digits after the decimal point. User configuration of these values ought to be limited in the same
     1728         fashion.
     1729      </p>
     1730      <div id="rfc.iref.a.1"></div>
     1731      <div id="rfc.iref.h.8"></div>
     1732      <h3 id="rfc.section.6.3.2"><a href="#rfc.section.6.3.2">6.3.2</a>&nbsp;<a id="header.accept" href="#header.accept">Accept</a></h3>
     1733      <p id="rfc.section.6.3.2.p.1">The "Accept" header field can be used by user agents to specify response media types that are acceptable. Accept header fields
     1734         can be used to indicate that the request is specifically limited to a small set of desired types, as in the case of a request
     1735         for an in-line image.
     1736      </p>
     1737      <div id="rfc.figure.u.16"></div><pre class="inline"><span id="rfc.iref.g.15"></span><span id="rfc.iref.g.16"></span><span id="rfc.iref.g.17"></span><span id="rfc.iref.g.18"></span>  <a href="#header.accept" class="smpl">Accept</a> = #( <a href="#header.accept" class="smpl">media-range</a> [ <a href="#header.accept" class="smpl">accept-params</a> ] )
     1738 
     1739  <a href="#header.accept" class="smpl">media-range</a>    = ( "*/*"
     1740                   / ( <a href="#media.types" class="smpl">type</a> "/" "*" )
     1741                   / ( <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> )
     1742                   ) *( <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> )
     1743  <a href="#header.accept" class="smpl">accept-params</a>  = <a href="#quality.values" class="smpl">weight</a> *( <a href="#header.accept" class="smpl">accept-ext</a> )
     1744  <a href="#header.accept" class="smpl">accept-ext</a>     = <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#imported.abnf" class="smpl">token</a> [ "=" <a href="#imported.abnf" class="smpl">word</a> ]
     1745</pre><p id="rfc.section.6.3.2.p.3">The asterisk "*" character is used to group media types into ranges, with "*/*" indicating all media types and "type/*" indicating
     1746         all subtypes of that type. The media-range <em class="bcp14">MAY</em> include media type parameters that are applicable to that range.
     1747      </p>
     1748      <p id="rfc.section.6.3.2.p.4">Each media-range <em class="bcp14">MAY</em> be followed by one or more accept-params, beginning with the "q" parameter for indicating a relative weight, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>. The first "q" parameter (if any) separates the media-range parameter(s) from the accept-params.
     1749      </p>
     1750      <div class="note" id="rfc.section.6.3.2.p.5">
     1751         <p> <b>Note:</b> Use of the "q" parameter name to separate media type parameters from Accept extension parameters is due to historical practice.
     1752            Although this prevents any media type parameter named "q" from being used with a media range, such an event is believed to
     1753            be unlikely given the lack of any "q" parameters in the IANA media type registry and the rare usage of any media type parameters
     1754            in Accept. Future media types are discouraged from registering any parameter named "q".
     1755         </p>
     1756      </div>
     1757      <p id="rfc.section.6.3.2.p.6">The example</p>
     1758      <div id="rfc.figure.u.17"></div><pre class="text">  Accept: audio/*; q=0.2, audio/basic
     1759</pre><p id="rfc.section.6.3.2.p.8"> <em class="bcp14">SHOULD</em> be interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% mark-down in
     1760         quality".
     1761      </p>
     1762      <p id="rfc.section.6.3.2.p.9">A request without any Accept header field implies that the user agent will accept any media type in response. If an Accept
     1763         header field is present in a request and none of the available representations for the response have a media type that is
     1764         listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept header field by sending a <a href="#status.406" class="smpl">406 (Not Acceptable)</a> response or disregard the Accept header field by treating the response as if it is not subject to content negotiation.
     1765      </p>
     1766      <p id="rfc.section.6.3.2.p.10">A more elaborate example is</p>
     1767      <div id="rfc.figure.u.18"></div><pre class="text">  Accept: text/plain; q=0.5, text/html,
     1768          text/x-dvi; q=0.8, text/x-c
     1769</pre><p id="rfc.section.6.3.2.p.12">Verbally, this would be interpreted as "text/html and text/x-c are the preferred media types, but if they do not exist, then
     1770         send the text/x-dvi representation, and if that does not exist, send the text/plain representation".
     1771      </p>
     1772      <p id="rfc.section.6.3.2.p.13">Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies
     1773         to a given type, the most specific reference has precedence. For example,
     1774      </p>
     1775      <div id="rfc.figure.u.19"></div><pre class="text">  Accept: text/*, text/plain, text/plain;format=flowed, */*
     1776</pre><p id="rfc.section.6.3.2.p.15">have the following precedence: </p>
     1777      <ol>
     1778         <li>text/plain;format=flowed</li>
     1779         <li>text/plain</li>
     1780         <li>text/*</li>
     1781         <li>*/*</li>
     1782      </ol>
     1783      <p id="rfc.section.6.3.2.p.16">The media type quality factor associated with a given type is determined by finding the media range with the highest precedence
     1784         which matches that type. For example,
     1785      </p>
     1786      <div id="rfc.figure.u.20"></div><pre class="text">  Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1,
     1787          text/html;level=2;q=0.4, */*;q=0.5
     1788</pre><p id="rfc.section.6.3.2.p.18">would cause the following values to be associated:</p>
     1789      <div id="rfc.table.u.7">
     1790         <table class="tt full left" cellpadding="3" cellspacing="0">
     1791            <thead>
     1792               <tr>
     1793                  <th>Media Type</th>
     1794                  <th>Quality Value</th>
     1795               </tr>
     1796            </thead>
     1797            <tbody>
     1798               <tr>
     1799                  <td class="left">text/html;level=1</td>
     1800                  <td class="left">1</td>
     1801               </tr>
     1802               <tr>
     1803                  <td class="left">text/html</td>
     1804                  <td class="left">0.7</td>
     1805               </tr>
     1806               <tr>
     1807                  <td class="left">text/plain</td>
     1808                  <td class="left">0.3</td>
     1809               </tr>
     1810               <tr>
     1811                  <td class="left">image/jpeg</td>
     1812                  <td class="left">0.5</td>
     1813               </tr>
     1814               <tr>
     1815                  <td class="left">text/html;level=2</td>
     1816                  <td class="left">0.4</td>
     1817               </tr>
     1818               <tr>
     1819                  <td class="left">text/html;level=3</td>
     1820                  <td class="left">0.7</td>
     1821               </tr>
     1822            </tbody>
     1823         </table>
     1824      </div>
     1825      <p id="rfc.section.6.3.2.p.19"> <b>Note:</b> A user agent might be provided with a default set of quality values for certain media ranges. However, unless the user agent
     1826         is a closed system which cannot interact with other rendering agents, this default set ought to be configurable by the user.
     1827      </p>
     1828      <div id="rfc.iref.a.2"></div>
     1829      <div id="rfc.iref.h.9"></div>
     1830      <h3 id="rfc.section.6.3.3"><a href="#rfc.section.6.3.3">6.3.3</a>&nbsp;<a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h3>
     1831      <p id="rfc.section.6.3.3.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response
     1832         payload. This field allows clients capable of understanding more comprehensive or special-purpose character encodings to signal
     1833         that capability to a server which is capable of representing documents in those character encodings.
     1834      </p>
     1835      <div id="rfc.figure.u.21"></div><pre class="inline"><span id="rfc.iref.g.19"></span>  <a href="#header.accept-charset" class="smpl">Accept-Charset</a> = 1#( ( <a href="#rule.charset" class="smpl">charset</a> / "*" ) [ <a href="#quality.values" class="smpl">weight</a> ] )
     1836</pre><p id="rfc.section.6.3.3.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section&nbsp;9.3</a>. Each charset <em class="bcp14">MAY</em> be given an associated quality value which represents the user's preference for that charset, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>. An example is
     1837      </p>
     1838      <div id="rfc.figure.u.22"></div><pre class="text">  Accept-Charset: iso-8859-5, unicode-1-1;q=0.8
     1839</pre><p id="rfc.section.6.3.3.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere
     1840         in the Accept-Charset field. If no "*" is present in an Accept-Charset field, then any character encodings not explicitly
     1841         mentioned in the field are considered "not acceptable" to the client.
     1842      </p>
     1843      <p id="rfc.section.6.3.3.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response.</p>
     1844      <p id="rfc.section.6.3.3.p.7">If an Accept-Charset header field is present in a request and none of the available representations for the response have
     1845         a character encoding that is listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept-Charset header field by sending a <a href="#status.406" class="smpl">406 (Not Acceptable)</a> response or disregard the Accept-Charset header field by treating the response as if it is not subject to content negotiation.
     1846      </p>
     1847      <div id="rfc.iref.a.3"></div>
     1848      <div id="rfc.iref.h.10"></div>
     1849      <h3 id="rfc.section.6.3.4"><a href="#rfc.section.6.3.4">6.3.4</a>&nbsp;<a id="header.accept-encoding" href="#header.accept-encoding">Accept-Encoding</a></h3>
     1850      <p id="rfc.section.6.3.4.p.1">The "Accept-Encoding" header field can be used by user agents to indicate what response content-codings (<a href="#content.codings" title="Content Codings">Section&nbsp;9.4</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when
     1851         no encoding is preferred.
     1852      </p>
     1853      <div id="rfc.figure.u.23"></div><pre class="inline"><span id="rfc.iref.g.20"></span><span id="rfc.iref.g.21"></span>  <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a>  = #( <a href="#header.accept-encoding" class="smpl">codings</a> [ <a href="#quality.values" class="smpl">weight</a> ] )
     1854  <a href="#header.accept-encoding" class="smpl">codings</a>          = <a href="#content.codings" class="smpl">content-coding</a> / "identity" / "*"
     1855</pre><p id="rfc.section.6.3.4.p.3">Each codings value <em class="bcp14">MAY</em> be given an associated quality value which represents the preference for that encoding, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>.
     1856      </p>
     1857      <p id="rfc.section.6.3.4.p.4">For example,</p>
     1858      <div id="rfc.figure.u.24"></div><pre class="text">  Accept-Encoding: compress, gzip
     1859  Accept-Encoding:
     1860  Accept-Encoding: *
     1861  Accept-Encoding: compress;q=0.5, gzip;q=1.0
     1862  Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0
     1863</pre><p id="rfc.section.6.3.4.p.6">A server tests whether a content-coding for a given representation is acceptable, according to an Accept-Encoding field, using
     1864         these rules:
     1865      </p>
     1866      <ol>
     1867         <li>The special "*" symbol in an Accept-Encoding field matches any available content-coding not explicitly listed in the header
     1868            field.
     1869         </li>
     1870         <li>If the representation has no content-coding, then it is acceptable by default unless specifically excluded by the Accept-Encoding
     1871            field stating either "identity;q=0" or "*;q=0" without a more specific entry for "identity".
     1872         </li>
     1873         <li>If the representation's content-coding is one of the content-codings listed in the Accept-Encoding field, then it is acceptable
     1874            unless it is accompanied by a qvalue of 0. (As defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>, a qvalue of 0 means "not acceptable".)
     1875         </li>
     1876         <li>If multiple content-codings are acceptable, then the acceptable content-coding with the highest non-zero qvalue is preferred.</li>
     1877      </ol>
     1878      <p id="rfc.section.6.3.4.p.7">An Accept-Encoding header field with a combined field-value that is empty implies that the user agent does not want any content-coding
     1879         in response. If an Accept-Encoding header field is present in a request and none of the available representations for the
     1880         response have a content-coding that is listed as acceptable, the origin server <em class="bcp14">SHOULD</em> send a response without any content-coding.
     1881      </p>
     1882      <p id="rfc.section.6.3.4.p.8">A request without an Accept-Encoding header field implies that the user agent will accept any content-coding in response.</p>
     1883      <div class="note" id="rfc.section.6.3.4.p.9">
     1884         <p> <b>Note:</b> Most HTTP/1.0 applications do not recognize or obey qvalues associated with content-codings. This means that qvalues will
     1885            not work and are not permitted with x-gzip or x-compress.
     1886         </p>
     1887      </div>
     1888      <div id="rfc.iref.a.4"></div>
     1889      <div id="rfc.iref.h.11"></div>
     1890      <h3 id="rfc.section.6.3.5"><a href="#rfc.section.6.3.5">6.3.5</a>&nbsp;<a id="header.accept-language" href="#header.accept-language">Accept-Language</a></h3>
     1891      <p id="rfc.section.6.3.5.p.1">The "Accept-Language" header field can be used by user agents to indicate the set of natural languages that are preferred
     1892         in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;9.6</a>.
     1893      </p>
     1894      <div id="rfc.figure.u.25"></div><pre class="inline"><span id="rfc.iref.g.22"></span><span id="rfc.iref.g.23"></span>  <a href="#header.accept-language" class="smpl">Accept-Language</a> = 1#( <a href="#header.accept-language" class="smpl">language-range</a> [ <a href="#quality.values" class="smpl">weight</a> ] )
     1895  <a href="#header.accept-language" class="smpl">language-range</a>  =
     1896            &lt;language-range, defined in <a href="#RFC4647" id="rfc.xref.RFC4647.1"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-2.1">Section 2.1</a>&gt;
     1897</pre><p id="rfc.section.6.3.5.p.3">Each language-range can be given an associated quality value which represents an estimate of the user's preference for the
     1898         languages specified by that range, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>. For example,
     1899      </p>
     1900      <div id="rfc.figure.u.26"></div><pre class="text">  Accept-Language: da, en-gb;q=0.8, en;q=0.7
     1901</pre><p id="rfc.section.6.3.5.p.5">would mean: "I prefer Danish, but will accept British English and other types of English". (see also <a href="http://tools.ietf.org/html/rfc4647#section-2.3">Section 2.3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.2"><cite title="Matching of Language Tags">[RFC4647]</cite></a>)
     1902      </p>
     1903      <p id="rfc.section.6.3.5.p.6">For matching, <a href="http://tools.ietf.org/html/rfc4647#section-3">Section 3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.3"><cite title="Matching of Language Tags">[RFC4647]</cite></a> defines several matching schemes. Implementations can offer the most appropriate matching scheme for their requirements.
     1904      </p>
     1905      <div class="note" id="rfc.section.6.3.5.p.7">
     1906         <p> <b>Note:</b> The "Basic Filtering" scheme (<a href="#RFC4647" id="rfc.xref.RFC4647.4"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-3.3.1">Section 3.3.1</a>) is identical to the matching scheme that was previously defined in <a href="http://tools.ietf.org/html/rfc2616#section-14.4">Section 14.4</a> of <a href="#RFC2616" id="rfc.xref.RFC2616.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>.
     1907         </p>
     1908      </div>
     1909      <p id="rfc.section.6.3.5.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic
     1910         preferences of the user in every request. For a discussion of this issue, see <a href="#privacy.issues.connected.to.accept.header.fields" title="Privacy Issues Connected to Accept Header Fields">Section&nbsp;11.5</a>.
     1911      </p>
     1912      <p id="rfc.section.6.3.5.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice
     1913         of linguistic preference available to the user. If the choice is not made available, then the Accept-Language header field <em class="bcp14">MUST NOT</em> be given in the request.
     1914      </p>
     1915      <div class="note" id="rfc.section.6.3.5.p.10">
     1916         <p> <b>Note:</b> When making the choice of linguistic preference available to the user, we remind implementers of the fact that users are not
     1917            familiar with the details of language matching as described above, and ought to be provided appropriate guidance. As an example,
     1918            users might assume that on selecting "en-gb", they will be served any kind of English document if British English is not available.
     1919            A user agent might suggest in such a case to add "en" to get the best matching behavior.
     1920         </p>
     1921      </div>
    15731922      <h2 id="rfc.section.6.4"><a href="#rfc.section.6.4">6.4</a>&nbsp;<a id="request.auth" href="#request.auth">Authentication</a></h2>
    1574       <div id="rfc.table.u.7">
     1923      <div id="rfc.table.u.8">
    15751924         <table class="tt full left" cellpadding="3" cellspacing="0">
    15761925            <thead>
    … …  
    15931942      </div>
    15941943      <h2 id="rfc.section.6.5"><a href="#rfc.section.6.5">6.5</a>&nbsp;<a id="request.context" href="#request.context">Context</a></h2>
    1595       <div id="rfc.table.u.8">
     1944      <div id="rfc.table.u.9">
    15961945         <table class="tt full left" cellpadding="3" cellspacing="0">
    15971946            <thead>
    … …  
    16041953               <tr>
    16051954                  <td class="left">From</td>
    1606                   <td class="left"><a href="#header.from" id="rfc.xref.header.from.1" title="From">Section&nbsp;10.12</a></td>
     1955                  <td class="left"><a href="#header.from" id="rfc.xref.header.from.1" title="From">Section&nbsp;6.5.1</a></td>
    16071956               </tr>
    16081957               <tr>
    16091958                  <td class="left">Referer</td>
    1610                   <td class="left"><a href="#header.referer" id="rfc.xref.header.referer.1" title="Referer">Section&nbsp;10.15</a></td>
     1959                  <td class="left"><a href="#header.referer" id="rfc.xref.header.referer.1" title="Referer">Section&nbsp;6.5.2</a></td>
    16111960               </tr>
    16121961               <tr>
    16131962                  <td class="left">TE</td>
    1614                   <td class="left"><a href="p1-messaging.html#header.te" title="TE">Section 4.3</a> of <a href="#Part1" id="rfc.xref.Part1.16"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a></td>
     1963                  <td class="left"><a href="p1-messaging.html#header.te" title="TE">Section 4.3</a> of <a href="#Part1" id="rfc.xref.Part1.18"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a></td>
    16151964               </tr>
    16161965               <tr>
    16171966                  <td class="left">User-Agent</td>
    1618                   <td class="left"><a href="#header.user-agent" id="rfc.xref.header.user-agent.2" title="User-Agent">Section&nbsp;10.18</a></td>
     1967                  <td class="left"><a href="#header.user-agent" id="rfc.xref.header.user-agent.2" title="User-Agent">Section&nbsp;6.5.3</a></td>
    16191968               </tr>
    16201969            </tbody>
    16211970         </table>
    16221971      </div>
    1623       <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a id="status.codes" href="#status.codes">Response Status Codes</a></h1>
     1972      <div id="rfc.iref.f.1"></div>
     1973      <div id="rfc.iref.h.12"></div>
     1974      <h3 id="rfc.section.6.5.1"><a href="#rfc.section.6.5.1">6.5.1</a>&nbsp;<a id="header.from" href="#header.from">From</a></h3>
     1975      <p id="rfc.section.6.5.1.p.1">The "From" header field, if given, <em class="bcp14">SHOULD</em> contain an Internet e-mail address for the human user who controls the requesting user agent. The address <em class="bcp14">SHOULD</em> be machine-usable, as defined by "mailbox" in <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.1"><cite title="Internet Message Format">[RFC5322]</cite></a>:
     1976      </p>
     1977      <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.24"></span>  <a href="#header.from" class="smpl">From</a>    = <a href="#header.from" class="smpl">mailbox</a>
     1978 
     1979  <a href="#header.from" class="smpl">mailbox</a> = &lt;mailbox, defined in <a href="#RFC5322" id="rfc.xref.RFC5322.2"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a>&gt;
     1980</pre><p id="rfc.section.6.5.1.p.3">An example is:</p>
     1981      <div id="rfc.figure.u.28"></div><pre class="text">  From: webmaster@example.org
     1982</pre><p id="rfc.section.6.5.1.p.5">This header field <em class="bcp14">MAY</em> be used for logging purposes and as a means for identifying the source of invalid or unwanted requests. It <em class="bcp14">SHOULD NOT</em> be used as an insecure form of access protection. The interpretation of this field is that the request is being performed
     1983         on behalf of the person given, who accepts responsibility for the method performed. In particular, robot agents <em class="bcp14">SHOULD</em> include this header field so that the person responsible for running the robot can be contacted if problems occur on the receiving
     1984         end.
     1985      </p>
     1986      <p id="rfc.section.6.5.1.p.6">The Internet e-mail address in this field <em class="bcp14">MAY</em> be separate from the Internet host which issued the request. For example, when a request is passed through a proxy the original
     1987         issuer's address <em class="bcp14">SHOULD</em> be used.
     1988      </p>
     1989      <p id="rfc.section.6.5.1.p.7">The client <em class="bcp14">SHOULD NOT</em> send the From header field without the user's approval, as it might conflict with the user's privacy interests or their site's
     1990         security policy. It is strongly recommended that the user be able to disable, enable, and modify the value of this field at
     1991         any time prior to a request.
     1992      </p>
     1993      <div id="rfc.iref.r.2"></div>
     1994      <div id="rfc.iref.h.13"></div>
     1995      <h3 id="rfc.section.6.5.2"><a href="#rfc.section.6.5.2">6.5.2</a>&nbsp;<a id="header.referer" href="#header.referer">Referer</a></h3>
     1996      <p id="rfc.section.6.5.2.p.1">The "Referer" [sic] header field allows the client to specify the URI of the resource from which the target URI was obtained
     1997         (the "referrer", although the header field is misspelled.).
     1998      </p>
     1999      <p id="rfc.section.6.5.2.p.2">The Referer header field allows servers to generate lists of back-links to resources for interest, logging, optimized caching,
     2000         etc. It also allows obsolete or mistyped links to be traced for maintenance. Some servers use Referer as a means of controlling
     2001         where they allow links from (so-called "deep linking"), but legitimate requests do not always contain a Referer header field.
     2002      </p>
     2003      <p id="rfc.section.6.5.2.p.3">If the target URI was obtained from a source that does not have its own URI (e.g., input from the user keyboard), the Referer
     2004         field <em class="bcp14">MUST</em> either be sent with the value "about:blank", or not be sent at all. Note that this requirement does not apply to sources with
     2005         non-HTTP URIs (e.g., FTP).
     2006      </p>
     2007      <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.25"></span>  <a href="#header.referer" class="smpl">Referer</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a>
     2008</pre><p id="rfc.section.6.5.2.p.5">Example:</p>
     2009      <div id="rfc.figure.u.30"></div><pre class="text">  Referer: http://www.example.org/hypertext/Overview.html
     2010</pre><p id="rfc.section.6.5.2.p.7">If the field value is a relative URI, it <em class="bcp14">SHOULD</em> be interpreted relative to the effective request URI. The URI <em class="bcp14">MUST NOT</em> include a fragment. See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section&nbsp;11.2</a> for security considerations.
     2011      </p>
     2012      <div id="rfc.iref.u.1"></div>
     2013      <div id="rfc.iref.h.14"></div>
     2014      <h3 id="rfc.section.6.5.3"><a href="#rfc.section.6.5.3">6.5.3</a>&nbsp;<a id="header.user-agent" href="#header.user-agent">User-Agent</a></h3>
     2015      <p id="rfc.section.6.5.3.p.1">The "User-Agent" header field contains information about the user agent originating the request. User agents <em class="bcp14">SHOULD</em> include this field with requests.
     2016      </p>
     2017      <p id="rfc.section.6.5.3.p.2">Typically, it is used for statistical purposes, the tracing of protocol violations, and tailoring responses to avoid particular
     2018         user agent limitations.
     2019      </p>
     2020      <p id="rfc.section.6.5.3.p.3">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section&nbsp;9.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.19"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) identifying the agent and its significant subproducts. By convention, the product tokens are listed in order of their significance
     2021         for identifying the application.
     2022      </p>
     2023      <p id="rfc.section.6.5.3.p.4">Because this field is usually sent on every request a user agent makes, implementations are encouraged not to include needlessly
     2024         fine-grained detail, and to limit (or even prohibit) the addition of subproducts by third parties. Overly long and detailed
     2025         User-Agent field values make requests larger and can also be used to identify ("fingerprint") the user against their wishes.
     2026      </p>
     2027      <p id="rfc.section.6.5.3.p.5">Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility
     2028         with them, as this circumvents the purpose of the field. Finally, they are encouraged not to use comments to identify products;
     2029         doing so makes the field value more difficult to parse.
     2030      </p>
     2031      <div id="rfc.figure.u.31"></div><pre class="inline"><span id="rfc.iref.g.26"></span>  <a href="#header.user-agent" class="smpl">User-Agent</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) )
     2032</pre><p id="rfc.section.6.5.3.p.7">Example:</p>
     2033      <div id="rfc.figure.u.32"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
     2034</pre><h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a id="status.codes" href="#status.codes">Response Status Codes</a></h1>
    16242035      <p id="rfc.section.7.p.1">The status-code element is a 3-digit integer result code of the attempt to understand and satisfy the request.</p>
    16252036      <p id="rfc.section.7.p.2">HTTP status codes are extensible. HTTP applications are not required to understand the meaning of all registered status codes,
    … …  
    16442055         </li>
    16452056      </ul>
    1646       <p id="rfc.section.7.p.4">For most status codes the response can carry a payload, in which case a <a href="#header.content-type" class="smpl">Content-Type</a> header field indicates the payload's media type (<a href="#header.content-type" id="rfc.xref.header.content-type.2" title="Content-Type">Section&nbsp;10.9</a>).
     2057      <p id="rfc.section.7.p.4">For most status codes the response can carry a payload, in which case a <a href="#header.content-type" class="smpl">Content-Type</a> header field indicates the payload's media type (<a href="#header.content-type" id="rfc.xref.header.content-type.2" title="Content-Type">Section&nbsp;3.2.1</a>).
    16472058      </p>
    16482059      <h2 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1</a>&nbsp;<a id="overview.of.status.codes" href="#overview.of.status.codes">Overview of Status Codes</a></h2>
    … …  
    16502061         protocol.
    16512062      </p>
    1652       <div id="rfc.table.u.9">
     2063      <div id="rfc.table.u.10">
    16532064         <table class="tt full left" cellpadding="3" cellspacing="0">
    16542065            <thead>
    … …  
    18702281      <p id="rfc.section.7.1.p.2">Note that this list is not exhaustive — it does not include extension status codes defined in other specifications.</p>
    18712282      <h2 id="rfc.section.7.2"><a href="#rfc.section.7.2">7.2</a>&nbsp;<a id="status.1xx" href="#status.1xx">Informational 1xx</a></h2>
    1872       <div id="rfc.iref.26"></div>
     2283      <div id="rfc.iref.75"></div>
    18732284      <div id="rfc.iref.s.3"></div>
    18742285      <p id="rfc.section.7.2.p.1">This class of status code indicates a provisional response, consisting only of the status-line and optional header fields,
    … …  
    18832294         a request, then it need not forward the corresponding <a href="#status.100" class="smpl">100 (Continue)</a> response(s).)
    18842295      </p>
    1885       <div id="rfc.iref.27"></div>
     2296      <div id="rfc.iref.76"></div>
    18862297      <div id="rfc.iref.s.4"></div>
    18872298      <h3 id="rfc.section.7.2.1"><a href="#rfc.section.7.2.1">7.2.1</a>&nbsp;<a id="status.100" href="#status.100">100 Continue</a></h3>
    18882299      <p id="rfc.section.7.2.1.p.1">The client <em class="bcp14">SHOULD</em> continue with its request. This interim response is used to inform the client that the initial part of the request has been
    18892300         received and has not yet been rejected by the server. The client <em class="bcp14">SHOULD</em> continue by sending the remainder of the request or, if the request has already been completed, ignore this response. The
    1890          server <em class="bcp14">MUST</em> send a final response after the request has been completed. See <a href="p1-messaging.html#use.of.the.100.status" title="Use of the 100 (Continue) Status">Section 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.17"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a> for detailed discussion of the use and handling of this status code.
    1891       </p>
    1892       <div id="rfc.iref.28"></div>
     2301         server <em class="bcp14">MUST</em> send a final response after the request has been completed. See <a href="p1-messaging.html#use.of.the.100.status" title="Use of the 100 (Continue) Status">Section 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.20"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a> for detailed discussion of the use and handling of this status code.
     2302      </p>
     2303      <div id="rfc.iref.77"></div>
    18932304      <div id="rfc.iref.s.5"></div>
    18942305      <h3 id="rfc.section.7.2.2"><a href="#rfc.section.7.2.2">7.2.2</a>&nbsp;<a id="status.101" href="#status.101">101 Switching Protocols</a></h3>
    1895       <p id="rfc.section.7.2.2.p.1">The server understands and is willing to comply with the client's request, via the <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> message header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.4</a> of <a href="#Part1" id="rfc.xref.Part1.18"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>), for a change in the application protocol being used on this connection. The server will switch protocols to those defined
     2306      <p id="rfc.section.7.2.2.p.1">The server understands and is willing to comply with the client's request, via the <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> message header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.4</a> of <a href="#Part1" id="rfc.xref.Part1.21"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>), for a change in the application protocol being used on this connection. The server will switch protocols to those defined
    18962307         by the response's Upgrade header field immediately after the empty line which terminates the 101 response.
    18972308      </p>
    … …  
    19012312      </p>
    19022313      <h2 id="rfc.section.7.3"><a href="#rfc.section.7.3">7.3</a>&nbsp;<a id="status.2xx" href="#status.2xx">Successful 2xx</a></h2>
    1903       <div id="rfc.iref.29"></div>
     2314      <div id="rfc.iref.78"></div>
    19042315      <div id="rfc.iref.s.6"></div>
    19052316      <p id="rfc.section.7.3.p.1">This class of status code indicates that the client's request was successfully received, understood, and accepted.</p>
    1906       <div id="rfc.iref.30"></div>
     2317      <div id="rfc.iref.79"></div>
    19072318      <div id="rfc.iref.s.7"></div>
    19082319      <h3 id="rfc.section.7.3.1"><a href="#rfc.section.7.3.1">7.3.1</a>&nbsp;<a id="status.200" href="#status.200">200 OK</a></h3>
    … …  
    19202331      <p id="rfc.section.7.3.1.p.2">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.9"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 200 responses.
    19212332      </p>
    1922       <div id="rfc.iref.31"></div>
     2333      <div id="rfc.iref.80"></div>
    19232334      <div id="rfc.iref.s.8"></div>
    19242335      <h3 id="rfc.section.7.3.2"><a href="#rfc.section.7.3.2">7.3.2</a>&nbsp;<a id="status.201" href="#status.201">201 Created</a></h3>
    … …  
    19332344         the <a href="#header.location" class="smpl">Location</a> header field or, in case the Location header field was omitted, by the Effective Request URI (see <a href="p4-conditional.html#header.etag" title="ETag">Section 2.3</a> of <a href="#Part4" id="rfc.xref.Part4.12"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a>).
    19342345      </p>
    1935       <div id="rfc.iref.32"></div>
     2346      <div id="rfc.iref.81"></div>
    19362347      <div id="rfc.iref.s.9"></div>
    19372348      <h3 id="rfc.section.7.3.3"><a href="#rfc.section.7.3.3">7.3.3</a>&nbsp;<a id="status.202" href="#status.202">202 Accepted</a></h3>
    … …  
    19452356         user can expect the request to be fulfilled.
    19462357      </p>
    1947       <div id="rfc.iref.33"></div>
     2358      <div id="rfc.iref.82"></div>
    19482359      <div id="rfc.iref.s.10"></div>
    19492360      <h3 id="rfc.section.7.3.4"><a href="#rfc.section.7.3.4">7.3.4</a>&nbsp;<a id="status.203" href="#status.203">203 Non-Authoritative Information</a></h3>
    1950       <p id="rfc.section.7.3.4.p.1">The representation in the response has been transformed or otherwise modified by a transforming proxy (<a href="p1-messaging.html#intermediaries" title="Intermediaries">Section 2.3</a> of <a href="#Part1" id="rfc.xref.Part1.19"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>). Note that the behavior of transforming intermediaries is controlled by the no-transform Cache-Control directive (<a href="p6-cache.html#header.cache-control" title="Cache-Control">Section 7.2</a> of <a href="#Part6" id="rfc.xref.Part6.10"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>).
     2361      <p id="rfc.section.7.3.4.p.1">The representation in the response has been transformed or otherwise modified by a transforming proxy (<a href="p1-messaging.html#intermediaries" title="Intermediaries">Section 2.3</a> of <a href="#Part1" id="rfc.xref.Part1.22"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>). Note that the behavior of transforming intermediaries is controlled by the no-transform Cache-Control directive (<a href="p6-cache.html#header.cache-control" title="Cache-Control">Section 7.2</a> of <a href="#Part6" id="rfc.xref.Part6.10"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>).
    19512362      </p>
    19522363      <p id="rfc.section.7.3.4.p.2">This status code is only appropriate when the response status code would have been <a href="#status.200" class="smpl">200 (OK)</a> otherwise. When the status code before transformation would have been different, the 214 Transformation Applied warn-code
    … …  
    19552366      <p id="rfc.section.7.3.4.p.3">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.12"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 203 responses.
    19562367      </p>
    1957       <div id="rfc.iref.34"></div>
     2368      <div id="rfc.iref.83"></div>
    19582369      <div id="rfc.iref.s.11"></div>
    19592370      <h3 id="rfc.section.7.3.5"><a href="#rfc.section.7.3.5">7.3.5</a>&nbsp;<a id="status.204" href="#status.204">204 No Content</a></h3>
    … …  
    19762387      <p id="rfc.section.7.3.5.p.5">The 204 response <em class="bcp14">MUST NOT</em> include a message body, and thus is always terminated by the first empty line after the header fields.
    19772388      </p>
    1978       <div id="rfc.iref.35"></div>
     2389      <div id="rfc.iref.84"></div>
    19792390      <div id="rfc.iref.s.12"></div>
    19802391      <h3 id="rfc.section.7.3.6"><a href="#rfc.section.7.3.6">7.3.6</a>&nbsp;<a id="status.205" href="#status.205">205 Reset Content</a></h3>
    … …  
    19832394         another input action.
    19842395      </p>
    1985       <p id="rfc.section.7.3.6.p.2">The message body included with the response <em class="bcp14">MUST</em> be empty. Note that receivers still need to parse the response according to the algorithm defined in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.20"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
     2396      <p id="rfc.section.7.3.6.p.2">The message body included with the response <em class="bcp14">MUST</em> be empty. Note that receivers still need to parse the response according to the algorithm defined in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.23"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
    19862397      </p>
    19872398      <h2 id="rfc.section.7.4"><a href="#rfc.section.7.4">7.4</a>&nbsp;<a id="status.3xx" href="#status.3xx">Redirection 3xx</a></h2>
    1988       <div id="rfc.iref.36"></div>
     2399      <div id="rfc.iref.85"></div>
    19892400      <div id="rfc.iref.s.13"></div>
    19902401      <p id="rfc.section.7.4.p.1">This class of status code indicates that further action needs to be taken by the user agent in order to fulfill the request.
    … …  
    20062417         </li>
    20072418         <li>
    2008             <p>Redirection offering a choice of matching resources for use by agent-driven content negotiation (<a href="#agent-driven.negotiation" title="Agent-driven Negotiation">Section&nbsp;3.4.2</a>). This is status code <a href="#status.300" class="smpl">300 (Multiple Choices)</a>.
     2419            <p>Redirection offering a choice of matching resources for use by agent-driven content negotiation (<a href="#agent-driven.negotiation" title="Agent-driven Negotiation">Section&nbsp;3.5.2</a>). This is status code <a href="#status.300" class="smpl">300 (Multiple Choices)</a>.
    20092420            </p>
    20102421         </li>
    … …  
    20182429         <p> <b>Note:</b> In HTTP/1.0, only the status codes <a href="#status.301" class="smpl">301 (Moved Permanently)</a> and <a href="#status.302" class="smpl">302 (Found)</a> were defined for the first type of redirect, and the second type did not exist at all (<a href="#RFC1945" id="rfc.xref.RFC1945.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.0">[RFC1945]</cite></a>, <a href="http://tools.ietf.org/html/rfc1945#section-9.3">Section 9.3</a>). However it turned out that web forms using POST expected redirects to change the operation for the subsequent request to
    20192430            retrieval (GET). To address this use case, HTTP/1.1 introduced the second type of redirect with the status code <a href="#status.303" class="smpl">303 (See Other)</a> (<a href="#RFC2068" id="rfc.xref.RFC2068.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a>, <a href="http://tools.ietf.org/html/rfc2068#section-10.3.4">Section 10.3.4</a>). As user agents did not change their behavior to maintain backwards compatibility, the first revision of HTTP/1.1 added
    2020             yet another status code, <a href="#status.307" class="smpl">307 (Temporary Redirect)</a>, for which the backwards compatibility problems did not apply (<a href="#RFC2616" id="rfc.xref.RFC2616.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>, <a href="http://tools.ietf.org/html/rfc2616#section-10.3.8">Section 10.3.8</a>). Over 10 years later, most user agents still do method rewriting for status codes <a href="#status.301" class="smpl">301</a> and <a href="#status.302" class="smpl">302</a>, therefore this specification makes that behavior conformant in case the original request was POST.
     2431            yet another status code, <a href="#status.307" class="smpl">307 (Temporary Redirect)</a>, for which the backwards compatibility problems did not apply (<a href="#RFC2616" id="rfc.xref.RFC2616.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>, <a href="http://tools.ietf.org/html/rfc2616#section-10.3.8">Section 10.3.8</a>). Over 10 years later, most user agents still do method rewriting for status codes <a href="#status.301" class="smpl">301</a> and <a href="#status.302" class="smpl">302</a>, therefore this specification makes that behavior conformant in case the original request was POST.
    20212432         </p>
    20222433      </div>
    2023       <p id="rfc.section.7.4.p.4">A <a href="#header.location" class="smpl">Location</a> header field on a 3xx response indicates that a client <em class="bcp14">MAY</em> automatically redirect to the URI provided; see <a href="#header.location" id="rfc.xref.header.location.2" title="Location">Section&nbsp;10.13</a>.
     2434      <p id="rfc.section.7.4.p.4">A <a href="#header.location" class="smpl">Location</a> header field on a 3xx response indicates that a client <em class="bcp14">MAY</em> automatically redirect to the URI provided; see <a href="#header.location" id="rfc.xref.header.location.2" title="Location">Section&nbsp;8.1.1</a>.
    20242435      </p>
    20252436      <p id="rfc.section.7.4.p.5">Note that for methods not known to be "safe", as defined in <a href="#safe.methods" title="Safe Methods">Section&nbsp;5.2.1</a>, automatic redirection needs to done with care, since the redirect might change the conditions under which the request was
    … …  
    20322443         </p>
    20332444      </div>
    2034       <div id="rfc.iref.37"></div>
     2445      <div id="rfc.iref.86"></div>
    20352446      <div id="rfc.iref.s.14"></div>
    20362447      <h3 id="rfc.section.7.4.1"><a href="#rfc.section.7.4.1">7.4.1</a>&nbsp;<a id="status.300" href="#status.300">300 Multiple Choices</a></h3>
    20372448      <p id="rfc.section.7.4.1.p.1">The target resource has more than one representation, each with its own specific location, and agent-driven negotiation information
    2038          (<a href="#content.negotiation" title="Content Negotiation">Section&nbsp;3.4</a>) is being provided so that the user (or user agent) can select a preferred representation by redirecting its request to that
     2449         (<a href="#content.negotiation" title="Content Negotiation">Section&nbsp;3.5</a>) is being provided so that the user (or user agent) can select a preferred representation by redirecting its request to that
    20392450         location.
    20402451      </p>
    … …  
    20472458      <p id="rfc.section.7.4.1.p.4">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.13"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 300 responses.
    20482459      </p>
    2049       <div id="rfc.iref.38"></div>
     2460      <div id="rfc.iref.87"></div>
    20502461      <div id="rfc.iref.s.15"></div>
    20512462      <h3 id="rfc.section.7.4.2"><a href="#rfc.section.7.4.2">7.4.2</a>&nbsp;<a id="status.301" href="#status.301">301 Moved Permanently</a></h3>
    … …  
    20612472         </p>
    20622473      </div>
    2063       <div id="rfc.iref.39"></div>
     2474      <div id="rfc.iref.88"></div>
    20642475      <div id="rfc.iref.s.16"></div>
    20652476      <h3 id="rfc.section.7.4.3"><a href="#rfc.section.7.4.3">7.4.3</a>&nbsp;<a id="status.302" href="#status.302">302 Found</a></h3>
    … …  
    20722483         </p>
    20732484      </div>
    2074       <div id="rfc.iref.40"></div>
     2485      <div id="rfc.iref.89"></div>
    20752486      <div id="rfc.iref.s.17"></div>
    20762487      <h3 id="rfc.section.7.4.4"><a href="#rfc.section.7.4.4">7.4.4</a>&nbsp;<a id="status.303" href="#status.303">303 See Other</a></h3>
    … …  
    20932504      <p id="rfc.section.7.4.4.p.4">Except for responses to a HEAD request, the representation of a 303 response <em class="bcp14">SHOULD</em> contain a short hypertext note with a hyperlink to the <a href="#header.location" class="smpl">Location</a> URI.
    20942505      </p>
    2095       <div id="rfc.iref.41"></div>
     2506      <div id="rfc.iref.90"></div>
    20962507      <div id="rfc.iref.s.18"></div>
    20972508      <h3 id="rfc.section.7.4.5"><a href="#rfc.section.7.4.5">7.4.5</a>&nbsp;<a id="status.305" href="#status.305">305 Use Proxy</a></h3>
    20982509      <p id="rfc.section.7.4.5.p.1">The 305 status code was defined in a previous version of this specification (see <a href="#changes.from.rfc.2616" title="Changes from RFC 2616">Appendix&nbsp;C</a>), and is now deprecated.
    20992510      </p>
    2100       <div id="rfc.iref.42"></div>
     2511      <div id="rfc.iref.91"></div>
    21012512      <div id="rfc.iref.s.19"></div>
    21022513      <h3 id="rfc.section.7.4.6"><a href="#rfc.section.7.4.6">7.4.6</a>&nbsp;<a id="status.306" href="#status.306">306 (Unused)</a></h3>
    21032514      <p id="rfc.section.7.4.6.p.1">The 306 status code was used in a previous version of the specification, is no longer used, and the code is reserved.</p>
    2104       <div id="rfc.iref.43"></div>
     2515      <div id="rfc.iref.92"></div>
    21052516      <div id="rfc.iref.s.20"></div>
    21062517      <h3 id="rfc.section.7.4.7"><a href="#rfc.section.7.4.7">7.4.7</a>&nbsp;<a id="status.307" href="#status.307">307 Temporary Redirect</a></h3>
    … …  
    21162527      </div>
    21172528      <h2 id="rfc.section.7.5"><a href="#rfc.section.7.5">7.5</a>&nbsp;<a id="status.4xx" href="#status.4xx">Client Error 4xx</a></h2>
    2118       <div id="rfc.iref.44"></div>
     2529      <div id="rfc.iref.93"></div>
    21192530      <div id="rfc.iref.s.21"></div>
    21202531      <p id="rfc.section.7.5.p.1">The 4xx class of status code is intended for cases in which the client seems to have erred. Except when responding to a HEAD
    … …  
    21222533         These status codes are applicable to any request method. User agents <em class="bcp14">SHOULD</em> display any included representation to the user.
    21232534      </p>
    2124       <div id="rfc.iref.45"></div>
     2535      <div id="rfc.iref.94"></div>
    21252536      <div id="rfc.iref.s.22"></div>
    21262537      <h3 id="rfc.section.7.5.1"><a href="#rfc.section.7.5.1">7.5.1</a>&nbsp;<a id="status.400" href="#status.400">400 Bad Request</a></h3>
    21272538      <p id="rfc.section.7.5.1.p.1">The server cannot or will not process the request, due to a client error (e.g., malformed syntax).</p>
    2128       <div id="rfc.iref.46"></div>
     2539      <div id="rfc.iref.95"></div>
    21292540      <div id="rfc.iref.s.23"></div>
    21302541      <h3 id="rfc.section.7.5.2"><a href="#rfc.section.7.5.2">7.5.2</a>&nbsp;<a id="status.402" href="#status.402">402 Payment Required</a></h3>
    21312542      <p id="rfc.section.7.5.2.p.1">This code is reserved for future use.</p>
    2132       <div id="rfc.iref.47"></div>
     2543      <div id="rfc.iref.96"></div>
    21332544      <div id="rfc.iref.s.24"></div>
    21342545      <h3 id="rfc.section.7.5.3"><a href="#rfc.section.7.5.3">7.5.3</a>&nbsp;<a id="status.403" href="#status.403">403 Forbidden</a></h3>
    … …  
    21402551            (Not Found)</a>  <em class="bcp14">MAY</em> be used instead.
    21412552      </p>
    2142       <div id="rfc.iref.48"></div>
     2553      <div id="rfc.iref.97"></div>
    21432554      <div id="rfc.iref.s.25"></div>
    21442555      <h3 id="rfc.section.7.5.4"><a href="#rfc.section.7.5.4">7.5.4</a>&nbsp;<a id="status.404" href="#status.404">404 Not Found</a></h3>
    … …  
    21482559         has been refused, or when no other response is applicable.
    21492560      </p>
    2150       <div id="rfc.iref.49"></div>
     2561      <div id="rfc.iref.98"></div>
    21512562      <div id="rfc.iref.s.26"></div>
    21522563      <h3 id="rfc.section.7.5.5"><a href="#rfc.section.7.5.5">7.5.5</a>&nbsp;<a id="status.405" href="#status.405">405 Method Not Allowed</a></h3>
    21532564      <p id="rfc.section.7.5.5.p.1">The method specified in the request-line is not allowed for the target resource. The response <em class="bcp14">MUST</em> include an <a href="#header.allow" class="smpl">Allow</a> header field containing a list of valid methods for the requested resource.
    21542565      </p>
    2155       <div id="rfc.iref.50"></div>
     2566      <div id="rfc.iref.99"></div>
    21562567      <div id="rfc.iref.s.27"></div>
    21572568      <h3 id="rfc.section.7.5.6"><a href="#rfc.section.7.5.6">7.5.6</a>&nbsp;<a id="status.406" href="#status.406">406 Not Acceptable</a></h3>
    … …  
    21712582      <p id="rfc.section.7.5.6.p.4">If the response could be unacceptable, a user agent <em class="bcp14">SHOULD</em> temporarily stop receipt of more data and query the user for a decision on further actions.
    21722583      </p>
    2173       <div id="rfc.iref.51"></div>
     2584      <div id="rfc.iref.100"></div>
    21742585      <div id="rfc.iref.s.28"></div>
    21752586      <h3 id="rfc.section.7.5.7"><a href="#rfc.section.7.5.7">7.5.7</a>&nbsp;<a id="status.408" href="#status.408">408 Request Timeout</a></h3>
    21762587      <p id="rfc.section.7.5.7.p.1">The client did not produce a request within the time that the server was prepared to wait. The client <em class="bcp14">MAY</em> repeat the request without modifications at any later time.
    21772588      </p>
    2178       <div id="rfc.iref.52"></div>
     2589      <div id="rfc.iref.101"></div>
    21792590      <div id="rfc.iref.s.29"></div>
    21802591      <h3 id="rfc.section.7.5.8"><a href="#rfc.section.7.5.8">7.5.8</a>&nbsp;<a id="status.409" href="#status.409">409 Conflict</a></h3>
    … …  
    21892600         contain a list of the differences between the two versions.
    21902601      </p>
    2191       <div id="rfc.iref.53"></div>
     2602      <div id="rfc.iref.102"></div>
    21922603      <div id="rfc.iref.s.30"></div>
    21932604      <h3 id="rfc.section.7.5.9"><a href="#rfc.section.7.5.9">7.5.9</a>&nbsp;<a id="status.410" href="#status.410">410 Gone</a></h3>
    … …  
    22042615      <p id="rfc.section.7.5.9.p.3">Caches <em class="bcp14">MAY</em> use a heuristic (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.1.2</a> of <a href="#Part6" id="rfc.xref.Part6.15"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) to determine freshness for 410 responses.
    22052616      </p>
    2206       <div id="rfc.iref.54"></div>
     2617      <div id="rfc.iref.103"></div>
    22072618      <div id="rfc.iref.s.31"></div>
    22082619      <h3 id="rfc.section.7.5.10"><a href="#rfc.section.7.5.10">7.5.10</a>&nbsp;<a id="status.411" href="#status.411">411 Length Required</a></h3>
    … …  
    22102621         message.
    22112622      </p>
    2212       <div id="rfc.iref.55"></div>
     2623      <div id="rfc.iref.104"></div>
    22132624      <div id="rfc.iref.s.32"></div>
    22142625      <h3 id="rfc.section.7.5.11"><a href="#rfc.section.7.5.11">7.5.11</a>&nbsp;<a id="status.413" href="#status.413">413 Request Representation Too Large</a></h3>
    … …  
    22182629      <p id="rfc.section.7.5.11.p.2">If the condition is temporary, the server <em class="bcp14">SHOULD</em> include a <a href="#header.retry-after" class="smpl">Retry-After</a> header field to indicate that it is temporary and after what time the client <em class="bcp14">MAY</em> try again.
    22192630      </p>
    2220       <div id="rfc.iref.56"></div>
     2631      <div id="rfc.iref.105"></div>
    22212632      <div id="rfc.iref.s.33"></div>
    22222633      <h3 id="rfc.section.7.5.12"><a href="#rfc.section.7.5.12">7.5.12</a>&nbsp;<a id="status.414" href="#status.414">414 URI Too Long</a></h3>
    … …  
    22272638         in some servers using fixed-length buffers for reading or manipulating the request-target.
    22282639      </p>
    2229       <div id="rfc.iref.57"></div>
     2640      <div id="rfc.iref.106"></div>
    22302641      <div id="rfc.iref.s.34"></div>
    22312642      <h3 id="rfc.section.7.5.13"><a href="#rfc.section.7.5.13">7.5.13</a>&nbsp;<a id="status.415" href="#status.415">415 Unsupported Media Type</a></h3>
    … …  
    22332644         on the target resource.
    22342645      </p>
    2235       <div id="rfc.iref.58"></div>
     2646      <div id="rfc.iref.107"></div>
    22362647      <div id="rfc.iref.s.35"></div>
    22372648      <h3 id="rfc.section.7.5.14"><a href="#rfc.section.7.5.14">7.5.14</a>&nbsp;<a id="status.417" href="#status.417">417 Expectation Failed</a></h3>
    2238       <p id="rfc.section.7.5.14.p.1">The expectation given in an <a href="#header.expect" class="smpl">Expect</a> header field (see <a href="#header.expect" id="rfc.xref.header.expect.2" title="Expect">Section&nbsp;10.11</a>) could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could
     2649      <p id="rfc.section.7.5.14.p.1">The expectation given in an <a href="#header.expect" class="smpl">Expect</a> header field (see <a href="#header.expect" id="rfc.xref.header.expect.2" title="Expect">Section&nbsp;6.1.2</a>) could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could
    22392650         not be met by the next-hop server.
    22402651      </p>
    2241       <div id="rfc.iref.59"></div>
     2652      <div id="rfc.iref.108"></div>
    22422653      <div id="rfc.iref.s.36"></div>
    22432654      <h3 id="rfc.section.7.5.15"><a href="#rfc.section.7.5.15">7.5.15</a>&nbsp;<a id="status.426" href="#status.426">426 Upgrade Required</a></h3>
    2244       <p id="rfc.section.7.5.15.p.1">The request can not be completed without a prior protocol upgrade. This response <em class="bcp14">MUST</em> include an <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.4</a> of <a href="#Part1" id="rfc.xref.Part1.21"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) specifying the required protocols.
    2245       </p>
    2246       <div id="rfc.figure.u.6"></div>
     2655      <p id="rfc.section.7.5.15.p.1">The request can not be completed without a prior protocol upgrade. This response <em class="bcp14">MUST</em> include an <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.4</a> of <a href="#Part1" id="rfc.xref.Part1.24"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) specifying the required protocols.
     2656      </p>
     2657      <div id="rfc.figure.u.33"></div>
    22472658      <p>Example:</p>  <pre class="text">HTTP/1.1 426 Upgrade Required
    22482659Upgrade: HTTP/3.0
    … …  
    22562667      </p>
    22572668      <h2 id="rfc.section.7.6"><a href="#rfc.section.7.6">7.6</a>&nbsp;<a id="status.5xx" href="#status.5xx">Server Error 5xx</a></h2>
    2258       <div id="rfc.iref.60"></div>
     2669      <div id="rfc.iref.109"></div>
    22592670      <div id="rfc.iref.s.37"></div>
    22602671      <p id="rfc.section.7.6.p.1">Response status codes beginning with the digit "5" indicate cases in which the server is aware that it has erred or is incapable
    … …  
    22622673         User agents <em class="bcp14">SHOULD</em> display any included representation to the user. These response codes are applicable to any request method.
    22632674      </p>
    2264       <div id="rfc.iref.61"></div>
     2675      <div id="rfc.iref.110"></div>
    22652676      <div id="rfc.iref.s.38"></div>
    22662677      <h3 id="rfc.section.7.6.1"><a href="#rfc.section.7.6.1">7.6.1</a>&nbsp;<a id="status.500" href="#status.500">500 Internal Server Error</a></h3>
    22672678      <p id="rfc.section.7.6.1.p.1">The server encountered an unexpected condition which prevented it from fulfilling the request.</p>
    2268       <div id="rfc.iref.62"></div>
     2679      <div id="rfc.iref.111"></div>
    22692680      <div id="rfc.iref.s.39"></div>
    22702681      <h3 id="rfc.section.7.6.2"><a href="#rfc.section.7.6.2">7.6.2</a>&nbsp;<a id="status.501" href="#status.501">501 Not Implemented</a></h3>
    … …  
    22722683         does not recognize the request method and is not capable of supporting it for any resource.
    22732684      </p>
    2274       <div id="rfc.iref.63"></div>
     2685      <div id="rfc.iref.112"></div>
    22752686      <div id="rfc.iref.s.40"></div>
    22762687      <h3 id="rfc.section.7.6.3"><a href="#rfc.section.7.6.3">7.6.3</a>&nbsp;<a id="status.502" href="#status.502">502 Bad Gateway</a></h3>
    … …  
    22782689         to fulfill the request.
    22792690      </p>
    2280       <div id="rfc.iref.64"></div>
     2691      <div id="rfc.iref.113"></div>
    22812692      <div id="rfc.iref.s.41"></div>
    22822693      <h3 id="rfc.section.7.6.4"><a href="#rfc.section.7.6.4">7.6.4</a>&nbsp;<a id="status.503" href="#status.503">503 Service Unavailable</a></h3>
    22832694      <p id="rfc.section.7.6.4.p.1">The server is currently unable to handle the request due to a temporary overloading or maintenance of the server.</p>
    22842695      <p id="rfc.section.7.6.4.p.2">The implication is that this is a temporary condition which will be alleviated after some delay. If known, the length of the
    2285          delay <em class="bcp14">MAY</em> be indicated in a <a href="#header.retry-after" class="smpl">Retry-After</a> header field (<a href="#header.retry-after" id="rfc.xref.header.retry-after.1" title="Retry-After">Section&nbsp;10.16</a>). If no Retry-After is given, the client <em class="bcp14">SHOULD</em> handle the response as it would for a <a href="#status.500" class="smpl">500 (Internal
     2696         delay <em class="bcp14">MAY</em> be indicated in a <a href="#header.retry-after" class="smpl">Retry-After</a> header field (<a href="#header.retry-after" id="rfc.xref.header.retry-after.1" title="Retry-After">Section&nbsp;8.1.2</a>). If no Retry-After is given, the client <em class="bcp14">SHOULD</em> handle the response as it would for a <a href="#status.500" class="smpl">500 (Internal
    22862697            Server Error)</a> response.
    22872698      </p>
    … …  
    22912702         </p>
    22922703      </div>
    2293       <div id="rfc.iref.65"></div>
     2704      <div id="rfc.iref.114"></div>
    22942705      <div id="rfc.iref.s.42"></div>
    22952706      <h3 id="rfc.section.7.6.5"><a href="#rfc.section.7.6.5">7.6.5</a>&nbsp;<a id="status.504" href="#status.504">504 Gateway Timeout</a></h3>
    … …  
    23022713         </p>
    23032714      </div>
    2304       <div id="rfc.iref.66"></div>
     2715      <div id="rfc.iref.115"></div>
    23052716      <div id="rfc.iref.s.43"></div>
    23062717      <h3 id="rfc.section.7.6.6"><a href="#rfc.section.7.6.6">7.6.6</a>&nbsp;<a id="status.505" href="#status.505">505 HTTP Version Not Supported</a></h3>
    23072718      <p id="rfc.section.7.6.6.p.1">The server does not support, or refuses to support, the protocol version that was used in the request message. The server
    23082719         is indicating that it is unable or unwilling to complete the request using the same major version as the client, as described
    2309          in <a href="p1-messaging.html#http.version" title="Protocol Versioning">Section 2.6</a> of <a href="#Part1" id="rfc.xref.Part1.22"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>, other than with this error message. The response <em class="bcp14">SHOULD</em> contain a representation describing why that version is not supported and what other protocols are supported by that server.
     2720         in <a href="p1-messaging.html#http.version" title="Protocol Versioning">Section 2.6</a> of <a href="#Part1" id="rfc.xref.Part1.25"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>, other than with this error message. The response <em class="bcp14">SHOULD</em> contain a representation describing why that version is not supported and what other protocols are supported by that server.
    23102721      </p>
    23112722      <h1 id="rfc.section.8"><a href="#rfc.section.8">8.</a>&nbsp;<a id="response.header.fields" href="#response.header.fields">Response Header Fields</a></h1>
    23122723      <p id="rfc.section.8.p.1">The response header fields allow the server to pass additional information about the response which cannot be placed in the
    2313          status-line. These header fields give information about the server and about further access to the target resource (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.23"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>).
     2724         status-line. These header fields give information about the server and about further access to the target resource (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.26"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>).
    23142725      </p>
    23152726      <h2 id="rfc.section.8.1"><a href="#rfc.section.8.1">8.1</a>&nbsp;<a id="response.control.data" href="#response.control.data">Control Data</a></h2>
    23162727      <p id="rfc.section.8.1.p.1">Response header fields can supply control data that supplements the status code or instructs the client where to go next.</p>
    2317       <div id="rfc.table.u.10">
     2728      <div id="rfc.table.u.11">
    23182729         <table class="tt full left" cellpadding="3" cellspacing="0">
    23192730            <thead>
    … …  
    23262737               <tr>
    23272738                  <td class="left">Location</td>
    2328                   <td class="left"><a href="#header.location" id="rfc.xref.header.location.3" title="Location">Section&nbsp;10.13</a></td>
     2739                  <td class="left"><a href="#header.location" id="rfc.xref.header.location.3" title="Location">Section&nbsp;8.1.1</a></td>
    23292740               </tr>
    23302741               <tr>
    23312742                  <td class="left">Retry-After</td>
    2332                   <td class="left"><a href="#header.retry-after" id="rfc.xref.header.retry-after.2" title="Retry-After">Section&nbsp;10.16</a></td>
     2743                  <td class="left"><a href="#header.retry-after" id="rfc.xref.header.retry-after.2" title="Retry-After">Section&nbsp;8.1.2</a></td>
    23332744               </tr>
    23342745            </tbody>
    23352746         </table>
    23362747      </div>
     2748      <div id="rfc.iref.l.1"></div>
     2749      <div id="rfc.iref.h.15"></div>
     2750      <h3 id="rfc.section.8.1.1"><a href="#rfc.section.8.1.1">8.1.1</a>&nbsp;<a id="header.location" href="#header.location">Location</a></h3>
     2751      <p id="rfc.section.8.1.1.p.1">The "Location" header field <em class="bcp14">MAY</em> be sent in responses to refer to a specific resource in accordance with the semantics of the status code.
     2752      </p>
     2753      <div id="rfc.figure.u.34"></div><pre class="inline"><span id="rfc.iref.g.27"></span>  <a href="#header.location" class="smpl">Location</a> = <a href="#imported.abnf" class="smpl">URI-reference</a>
     2754</pre><p id="rfc.section.8.1.1.p.3">For <a href="#status.201" class="smpl">201 (Created)</a> responses, the Location is the URI of the new resource which was created by the request. For <a href="#status.3xx" class="smpl">3xx (Redirection)</a> responses, the location <em class="bcp14">SHOULD</em> indicate the server's preferred URI for automatic redirection to the resource.
     2755      </p>
     2756      <p id="rfc.section.8.1.1.p.4">The field value consists of a single URI-reference. When it has the form of a relative reference (<a href="#RFC3986" id="rfc.xref.RFC3986.1"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-4.2">Section 4.2</a>), the final value is computed by resolving it against the effective request URI (<a href="#RFC3986" id="rfc.xref.RFC3986.2"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-5">Section 5</a>). If the original URI, as navigated to by the user agent, did contain a fragment identifier, and the final value does not,
     2757         then the original URI's fragment identifier is added to the final value.
     2758      </p>
     2759      <div id="rfc.figure.u.35"></div>
     2760      <p>For example, the original URI "http://www.example.org/~tim", combined with a field value given as:</p>  <pre class="text">  Location: /pub/WWW/People.html#tim
     2761</pre>  <p>would result in a final value of "http://www.example.org/pub/WWW/People.html#tim"</p>
     2762      <div id="rfc.figure.u.36"></div>
     2763      <p>An original URI "http://www.example.org/index.html#larry", combined with a field value given as:</p>  <pre class="text">  Location: http://www.example.net/index.html
     2764</pre>  <p>would result in a final value of "http://www.example.net/index.html#larry", preserving the original fragment identifier.</p>
     2765      <div class="note" id="rfc.section.8.1.1.p.7">
     2766         <p> <b>Note:</b> Some recipients attempt to recover from Location fields that are not valid URI references. This specification does not mandate
     2767            or define such processing, but does allow it.
     2768         </p>
     2769      </div>
     2770      <p id="rfc.section.8.1.1.p.8">There are circumstances in which a fragment identifier in a Location URI would not be appropriate. For instance, when it appears
     2771         in a <a href="#status.201" class="smpl">201
     2772            (Created)</a> response, where the Location header field specifies the URI for the entire created resource.
     2773      </p>
     2774      <div class="note" id="rfc.section.8.1.1.p.9">
     2775         <p> <b>Note:</b> The <a href="#header.content-location" class="smpl">Content-Location</a> header field (<a href="#header.content-location" id="rfc.xref.header.content-location.3" title="Content-Location">Section&nbsp;3.2.4</a>) differs from Location in that the Content-Location identifies the most specific resource corresponding to the enclosed representation.
     2776            It is therefore possible for a response to contain header fields for both Location and Content-Location.
     2777         </p>
     2778      </div>
     2779      <div id="rfc.iref.r.3"></div>
     2780      <div id="rfc.iref.h.16"></div>
     2781      <h3 id="rfc.section.8.1.2"><a href="#rfc.section.8.1.2">8.1.2</a>&nbsp;<a id="header.retry-after" href="#header.retry-after">Retry-After</a></h3>
     2782      <p id="rfc.section.8.1.2.p.1">The header "Retry-After" field can be used with a <a href="#status.503" class="smpl">503 (Service
     2783            Unavailable)</a> response to indicate how long the service is expected to be unavailable to the requesting client. This field <em class="bcp14">MAY</em> also be used with any <a href="#status.3xx" class="smpl">3xx (Redirection)</a> response to indicate the minimum time the user-agent is asked to wait before issuing the redirected request.
     2784      </p>
     2785      <p id="rfc.section.8.1.2.p.2">The value of this field can be either an HTTP-date or an integer number of seconds (in decimal) after the time of the response.</p>
     2786      <div id="rfc.figure.u.37"></div><pre class="inline"><span id="rfc.iref.g.28"></span>  <a href="#header.retry-after" class="smpl">Retry-After</a> = <a href="#http.date" class="smpl">HTTP-date</a> / <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>
     2787</pre><div id="rule.delta-seconds">
     2788         <p id="rfc.section.8.1.2.p.4">  Time spans are non-negative decimal integers, representing time in seconds.</p>
     2789      </div>
     2790      <div id="rfc.figure.u.38"></div><pre class="inline"><span id="rfc.iref.g.29"></span>  <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>  = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
     2791</pre><p id="rfc.section.8.1.2.p.6">Two examples of its use are</p>
     2792      <div id="rfc.figure.u.39"></div><pre class="text">  Retry-After: Fri, 31 Dec 1999 23:59:59 GMT
     2793  Retry-After: 120
     2794</pre><p id="rfc.section.8.1.2.p.8">In the latter example, the delay is 2 minutes.</p>
    23372795      <h2 id="rfc.section.8.2"><a href="#rfc.section.8.2">8.2</a>&nbsp;<a id="response.cache.related" href="#response.cache.related">Cache-related</a></h2>
    23382796      <p id="rfc.section.8.2.p.1">Cache-related response header fields provide metadata about the message in order to assist downstream caches.</p>
    2339       <div id="rfc.table.u.11">
     2797      <div id="rfc.table.u.12">
    23402798         <table class="tt full left" cellpadding="3" cellspacing="0">
    23412799            <thead>
    … …  
    23482806               <tr>
    23492807                  <td class="left">Date</td>
    2350                   <td class="left"><a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section&nbsp;10.10</a></td>
     2808                  <td class="left"><a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section&nbsp;8.2.1</a></td>
    23512809               </tr>
    23522810               <tr>
    … …  
    23612819         </table>
    23622820      </div>
     2821      <div id="rfc.iref.d.2"></div>
     2822      <div id="rfc.iref.h.17"></div>
     2823      <h3 id="rfc.section.8.2.1"><a href="#rfc.section.8.2.1">8.2.1</a>&nbsp;<a id="header.date" href="#header.date">Date</a></h3>
     2824      <p id="rfc.section.8.2.1.p.1">The "Date" header field represents the date and time at which the message was originated, having the same semantics as the
     2825         Origination Date Field (orig-date) defined in <a href="http://tools.ietf.org/html/rfc5322#section-3.6.1">Section 3.6.1</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.3"><cite title="Internet Message Format">[RFC5322]</cite></a>. The field value is an HTTP-date, as defined in <a href="#http.date" title="Date/Time Formats">Section&nbsp;9.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.
     2826      </p>
     2827      <div id="rfc.figure.u.40"></div><pre class="inline"><span id="rfc.iref.g.30"></span>  <a href="#header.date" class="smpl">Date</a> = <a href="#http.date" class="smpl">HTTP-date</a>
     2828</pre><p id="rfc.section.8.2.1.p.3">An example is</p>
     2829      <div id="rfc.figure.u.41"></div><pre class="text">  Date: Tue, 15 Nov 1994 08:12:31 GMT
     2830</pre><p id="rfc.section.8.2.1.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:
     2831      </p>
     2832      <ol>
     2833         <li>If the response status code is <a href="#status.100" class="smpl">100 (Continue)</a> or <a href="#status.101" class="smpl">101 (Switching Protocols)</a>, the response <em class="bcp14">MAY</em> include a Date header field, at the server's option.
     2834         </li>
     2835         <li>If the response status code conveys a server error, e.g., <a href="#status.500" class="smpl">500
     2836               (Internal Server Error)</a> or <a href="#status.503" class="smpl">503 (Service Unavailable)</a>, and it is inconvenient or impossible to generate a valid Date.
     2837         </li>
     2838         <li>If the server does not have a clock that can provide a reasonable approximation of the current time, its responses <em class="bcp14">MUST NOT</em> include a Date header field.
     2839         </li>
     2840      </ol>
     2841      <p id="rfc.section.8.2.1.p.6">A received message that does not have a Date header field <em class="bcp14">MUST</em> be assigned one by the recipient if the message will be cached by that recipient.
     2842      </p>
     2843      <p id="rfc.section.8.2.1.p.7">Clients can use the Date header field as well; in order to keep request messages small, they are advised not to include it
     2844         when it doesn't convey any useful information (as is usually the case for requests that do not contain a payload).
     2845      </p>
     2846      <p id="rfc.section.8.2.1.p.8">The HTTP-date sent in a Date header field <em class="bcp14">SHOULD NOT</em> represent a date and time subsequent to the generation of the message. It <em class="bcp14">SHOULD</em> represent the best available approximation of the date and time of message generation, unless the implementation has no means
     2847         of generating a reasonably accurate date and time. In theory, the date ought to represent the moment just before the payload
     2848         is generated. In practice, the date can be generated at any time during the message origination without affecting its semantic
     2849         value.
     2850      </p>
    23632851      <h2 id="rfc.section.8.3"><a href="#rfc.section.8.3">8.3</a>&nbsp;<a id="response.auth" href="#response.auth">Authentication Challenges</a></h2>
    2364       <p id="rfc.section.8.3.p.1">Authentication challenges indicate what mechanisms are available for the user or client to provide authentication credentials
    2365          in future requests.
    2366       </p>
    2367       <div id="rfc.table.u.12">
     2852      <p id="rfc.section.8.3.p.1">Authentication challenges indicate what mechanisms are available for the client to provide authentication credentials in future
     2853         requests.
     2854      </p>
     2855      <div id="rfc.table.u.13">
    23682856         <table class="tt full left" cellpadding="3" cellspacing="0">
    23692857            <thead>
    … …  
    23872875      <h2 id="rfc.section.8.4"><a href="#rfc.section.8.4">8.4</a>&nbsp;<a id="response.inform" href="#response.inform">Informative</a></h2>
    23882876      <p id="rfc.section.8.4.p.1">The remaining response header fields provide more information about the target resource for potential use in later requests.</p>
    2389       <div id="rfc.table.u.13">
     2877      <div id="rfc.table.u.14">
    23902878         <table class="tt full left" cellpadding="3" cellspacing="0">
    23912879            <thead>
    … …  
    24022890               <tr>
    24032891                  <td class="left">Allow</td>
    2404                   <td class="left"><a href="#header.allow" id="rfc.xref.header.allow.2" title="Allow">Section&nbsp;10.5</a></td>
     2892                  <td class="left"><a href="#header.allow" id="rfc.xref.header.allow.2" title="Allow">Section&nbsp;8.4.1</a></td>
    24052893               </tr>
    24062894               <tr>
    24072895                  <td class="left">Server</td>
    2408                   <td class="left"><a href="#header.server" id="rfc.xref.header.server.1" title="Server">Section&nbsp;10.17</a></td>
     2896                  <td class="left"><a href="#header.server" id="rfc.xref.header.server.1" title="Server">Section&nbsp;8.4.2</a></td>
    24092897               </tr>
    24102898            </tbody>
    24112899         </table>
     2900      </div>
     2901      <div id="rfc.iref.a.5"></div>
     2902      <div id="rfc.iref.h.18"></div>
     2903      <h3 id="rfc.section.8.4.1"><a href="#rfc.section.8.4.1">8.4.1</a>&nbsp;<a id="header.allow" href="#header.allow">Allow</a></h3>
     2904      <p id="rfc.section.8.4.1.p.1">The "Allow" header field lists the set of methods advertised as supported by the target resource. The purpose of this field
     2905         is strictly to inform the recipient of valid request methods associated with the resource.
     2906      </p>
     2907      <div id="rfc.figure.u.42"></div><pre class="inline"><span id="rfc.iref.g.31"></span>  <a href="#header.allow" class="smpl">Allow</a> = #<a href="#method.overview" class="smpl">method</a>
     2908</pre><p id="rfc.section.8.4.1.p.3">Example of use:</p>
     2909      <div id="rfc.figure.u.43"></div><pre class="text">  Allow: GET, HEAD, PUT
     2910</pre><p id="rfc.section.8.4.1.p.5">The actual set of allowed methods is defined by the origin server at the time of each request.</p>
     2911      <p id="rfc.section.8.4.1.p.6">A proxy <em class="bcp14">MUST NOT</em> modify the Allow header field — it does not need to understand all the methods specified in order to handle them according
     2912         to the generic message handling rules.
     2913      </p>
     2914      <div id="rfc.iref.s.44"></div>
     2915      <div id="rfc.iref.h.19"></div>
     2916      <h3 id="rfc.section.8.4.2"><a href="#rfc.section.8.4.2">8.4.2</a>&nbsp;<a id="header.server" href="#header.server">Server</a></h3>
     2917      <p id="rfc.section.8.4.2.p.1">The "Server" header field contains information about the software used by the origin server to handle the request.</p>
     2918      <p id="rfc.section.8.4.2.p.2">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section&nbsp;9.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.27"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) identifying the server and any significant subproducts. The product tokens are listed in order of their significance for
     2919         identifying the application.
     2920      </p>
     2921      <div id="rfc.figure.u.44"></div><pre class="inline"><span id="rfc.iref.g.32"></span>  <a href="#header.server" class="smpl">Server</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) )
     2922</pre><p id="rfc.section.8.4.2.p.4">Example:</p>
     2923      <div id="rfc.figure.u.45"></div><pre class="text">  Server: CERN/3.0 libwww/2.17
     2924</pre><p id="rfc.section.8.4.2.p.6">If the response is being forwarded through a proxy, the proxy application <em class="bcp14">MUST NOT</em> modify the <a href="#header.server" class="smpl">Server</a> header field. Instead, it <em class="bcp14">MUST</em> include a <a href="p1-messaging.html#header.via" class="smpl">Via</a> field (as described in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.28"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>).
     2925      </p>
     2926      <div class="note" id="rfc.section.8.4.2.p.7">
     2927         <p> <b>Note:</b> Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks
     2928            against software that is known to contain security holes. Server implementers are encouraged to make this field a configurable
     2929            option.
     2930         </p>
    24122931      </div>
    24132932      <h1 id="rfc.section.9"><a href="#rfc.section.9">9.</a>&nbsp;<a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h1>
    … …  
    24162935         a fixed-length subset of that defined by <a href="#RFC1123" id="rfc.xref.RFC1123.1"><cite title="Requirements for Internet Hosts - Application and Support">[RFC1123]</cite></a>:
    24172936      </p>
    2418       <div id="rfc.figure.u.7"></div><pre class="text">Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
     2937      <div id="rfc.figure.u.46"></div><pre class="text">Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
    24192938</pre><p id="rfc.section.9.1.p.3">The other formats are described here only for compatibility with obsolete implementations.</p>
    2420       <div id="rfc.figure.u.8"></div><pre class="text">Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format
     2939      <div id="rfc.figure.u.47"></div><pre class="text">Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format
    24212940Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format
    24222941</pre><p id="rfc.section.9.1.p.5">HTTP/1.1 clients and servers that parse a date value <em class="bcp14">MUST</em> accept all three formats (for compatibility with HTTP/1.0), though they <em class="bcp14">MUST</em> only generate the RFC 1123 format for representing HTTP-date values in header fields.
    … …  
    24262945         time zone, and <em class="bcp14">MUST</em> be assumed when reading the asctime format. HTTP-date is case sensitive and <em class="bcp14">MUST NOT</em> include additional whitespace beyond that specifically included as SP in the grammar.
    24272946      </p>
    2428       <div id="rfc.figure.u.9"></div><pre class="inline"><span id="rfc.iref.g.5"></span>  <a href="#http.date" class="smpl">HTTP-date</a>    = <a href="#preferred.date.format" class="smpl">rfc1123-date</a> / <a href="#obsolete.date.formats" class="smpl">obs-date</a>
     2947      <div id="rfc.figure.u.48"></div><pre class="inline"><span id="rfc.iref.g.33"></span>  <a href="#http.date" class="smpl">HTTP-date</a>    = <a href="#preferred.date.format" class="smpl">rfc1123-date</a> / <a href="#obsolete.date.formats" class="smpl">obs-date</a>
    24292948</pre><div id="preferred.date.format">
    24302949         <p id="rfc.section.9.1.p.8">                    Preferred format:</p>
    24312950      </div>
    2432       <div id="rfc.figure.u.10"></div><pre class="inline"><span id="rfc.iref.g.6"></span><span id="rfc.iref.g.7"></span><span id="rfc.iref.g.8"></span><span id="rfc.iref.g.9"></span><span id="rfc.iref.g.10"></span><span id="rfc.iref.g.11"></span><span id="rfc.iref.g.12"></span><span id="rfc.iref.g.13"></span><span id="rfc.iref.g.14"></span><span id="rfc.iref.g.15"></span><span id="rfc.iref.g.16"></span><span id="rfc.iref.g.17"></span>  <a href="#preferred.date.format" class="smpl">rfc1123-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> "," <a href="#imported.abnf" class="smpl">SP</a> date1 <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
     2951      <div id="rfc.figure.u.49"></div><pre class="inline"><span id="rfc.iref.g.34"></span><span id="rfc.iref.g.35"></span><span id="rfc.iref.g.36"></span><span id="rfc.iref.g.37"></span><span id="rfc.iref.g.38"></span><span id="rfc.iref.g.39"></span><span id="rfc.iref.g.40"></span><span id="rfc.iref.g.41"></span><span id="rfc.iref.g.42"></span><span id="rfc.iref.g.43"></span><span id="rfc.iref.g.44"></span><span id="rfc.iref.g.45"></span>  <a href="#preferred.date.format" class="smpl">rfc1123-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> "," <a href="#imported.abnf" class="smpl">SP</a> date1 <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
    24332952  ; fixed length subset of the format defined in
    24342953  ; <a href="http://tools.ietf.org/html/rfc1123#section-5.2.14">Section 5.2.14</a> of <a href="#RFC1123" id="rfc.xref.RFC1123.2"><cite title="Requirements for Internet Hosts - Application and Support">[RFC1123]</cite></a>
    … …  
    24682987  <a href="#preferred.date.format" class="smpl">minute</a>       = 2<a href="#imported.abnf" class="smpl">DIGIT</a>               
    24692988  <a href="#preferred.date.format" class="smpl">second</a>       = 2<a href="#imported.abnf" class="smpl">DIGIT</a>               
    2470 </pre><p id="rfc.section.9.1.p.10">The semantics of <a href="#preferred.date.format" class="smpl">day-name</a>, <a href="#preferred.date.format" class="smpl">day</a>, <a href="#preferred.date.format" class="smpl">month</a>, <a href="#preferred.date.format" class="smpl">year</a>, and <a href="#preferred.date.format" class="smpl">time-of-day</a> are the same as those defined for the RFC 5322 constructs with the corresponding name (<a href="#RFC5322" id="rfc.xref.RFC5322.1"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.3">Section 3.3</a>).
     2989</pre><p id="rfc.section.9.1.p.10">The semantics of <a href="#preferred.date.format" class="smpl">day-name</a>, <a href="#preferred.date.format" class="smpl">day</a>, <a href="#preferred.date.format" class="smpl">month</a>, <a href="#preferred.date.format" class="smpl">year</a>, and <a href="#preferred.date.format" class="smpl">time-of-day</a> are the same as those defined for the RFC 5322 constructs with the corresponding name (<a href="#RFC5322" id="rfc.xref.RFC5322.4"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.3">Section 3.3</a>).
    24712990      </p>
    24722991      <div id="obsolete.date.formats">
    24732992         <p id="rfc.section.9.1.p.11">              Obsolete formats:</p>
    24742993      </div>
    2475       <div id="rfc.figure.u.11"></div><pre class="inline"><span id="rfc.iref.g.18"></span>  <a href="#obsolete.date.formats" class="smpl">obs-date</a>     = <a href="#obsolete.date.formats" class="smpl">rfc850-date</a> / <a href="#obsolete.date.formats" class="smpl">asctime-date</a>
    2476 </pre><div id="rfc.figure.u.12"></div><pre class="inline"><span id="rfc.iref.g.19"></span>  <a href="#obsolete.date.formats" class="smpl">rfc850-date</a>  = <a href="#obsolete.date.formats" class="smpl">day-name-l</a> "," <a href="#imported.abnf" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date2</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
     2994      <div id="rfc.figure.u.50"></div><pre class="inline"><span id="rfc.iref.g.46"></span>  <a href="#obsolete.date.formats" class="smpl">obs-date</a>     = <a href="#obsolete.date.formats" class="smpl">rfc850-date</a> / <a href="#obsolete.date.formats" class="smpl">asctime-date</a>
     2995</pre><div id="rfc.figure.u.51"></div><pre class="inline"><span id="rfc.iref.g.47"></span>  <a href="#obsolete.date.formats" class="smpl">rfc850-date</a>  = <a href="#obsolete.date.formats" class="smpl">day-name-l</a> "," <a href="#imported.abnf" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date2</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
    24772996  <a href="#obsolete.date.formats" class="smpl">date2</a>        = <a href="#preferred.date.format" class="smpl">day</a> "-" <a href="#preferred.date.format" class="smpl">month</a> "-" 2<a href="#imported.abnf" class="smpl">DIGIT</a>
    24782997                 ; day-month-year (e.g., 02-Jun-82)
    … …  
    24853004         / %x53.61.74.75.72.64.61.79 ; "Saturday", case-sensitive
    24863005         / %x53.75.6E.64.61.79 ; "Sunday", case-sensitive
    2487 </pre><div id="rfc.figure.u.13"></div><pre class="inline"><span id="rfc.iref.g.20"></span>  <a href="#obsolete.date.formats" class="smpl">asctime-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date3</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">year</a>
     3006</pre><div id="rfc.figure.u.52"></div><pre class="inline"><span id="rfc.iref.g.48"></span>  <a href="#obsolete.date.formats" class="smpl">asctime-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date3</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">year</a>
    24883007  <a href="#obsolete.date.formats" class="smpl">date3</a>        = <a href="#preferred.date.format" class="smpl">month</a> <a href="#imported.abnf" class="smpl">SP</a> ( 2<a href="#imported.abnf" class="smpl">DIGIT</a> / ( <a href="#imported.abnf" class="smpl">SP</a> 1<a href="#imported.abnf" class="smpl">DIGIT</a> ))
    24893008                 ; month day (e.g., Jun  2)
    … …  
    25033022         By convention, the products are listed in order of their significance for identifying the application.
    25043023      </p>
    2505       <div id="rfc.figure.u.14"></div><pre class="inline"><span id="rfc.iref.g.21"></span><span id="rfc.iref.g.22"></span>  <a href="#product.tokens" class="smpl">product</a>         = <a href="#imported.abnf" class="smpl">token</a> ["/" <a href="#product.tokens" class="smpl">product-version</a>]
     3024      <div id="rfc.figure.u.53"></div><pre class="inline"><span id="rfc.iref.g.49"></span><span id="rfc.iref.g.50"></span>  <a href="#product.tokens" class="smpl">product</a>         = <a href="#imported.abnf" class="smpl">token</a> ["/" <a href="#product.tokens" class="smpl">product-version</a>]
    25063025  <a href="#product.tokens" class="smpl">product-version</a> = <a href="#imported.abnf" class="smpl">token</a>
    25073026</pre><p id="rfc.section.9.2.p.3">Examples:</p>
    2508       <div id="rfc.figure.u.15"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
     3027      <div id="rfc.figure.u.54"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
    25093028  Server: Apache/0.8.4
    25103029</pre><p id="rfc.section.9.2.p.5">Product tokens <em class="bcp14">SHOULD</em> be short and to the point. They <em class="bcp14">MUST NOT</em> be used for advertising or other non-essential information. Although any token octet <em class="bcp14">MAY</em> appear in a product-version, this token <em class="bcp14">SHOULD</em> only be used for a version identifier (i.e., successive versions of the same product <em class="bcp14">SHOULD</em> only differ in the product-version portion of the product value).
    … …  
    25173036         </p>
    25183037      </div>
    2519       <div id="rfc.figure.u.16"></div><pre class="inline"><span id="rfc.iref.g.23"></span>  <a href="#rule.charset" class="smpl">charset</a> = <a href="#imported.abnf" class="smpl">token</a>
     3038      <div id="rfc.figure.u.55"></div><pre class="inline"><span id="rfc.iref.g.51"></span>  <a href="#rule.charset" class="smpl">charset</a> = <a href="#imported.abnf" class="smpl">token</a>
    25203039</pre><p id="rfc.section.9.3.p.4">Although HTTP allows an arbitrary token to be used as a charset value, any token that has a predefined value within the IANA
    25213040         Character Set registry <em class="bcp14">MUST</em> represent the character encoding defined by that registry. Applications <em class="bcp14">SHOULD</em> limit their use of character encodings to those defined within the IANA registry.
    … …  
    25313050         directly, and only decoded by the recipient.
    25323051      </p>
    2533       <div id="rfc.figure.u.17"></div><pre class="inline"><span id="rfc.iref.g.24"></span>  <a href="#content.codings" class="smpl">content-coding</a>   = <a href="#imported.abnf" class="smpl">token</a>
    2534 </pre><p id="rfc.section.9.4.p.3">All content-coding values are case-insensitive. HTTP/1.1 uses content-coding values in the <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.3" title="Accept-Encoding">Section&nbsp;10.3</a>) and <a href="#header.content-encoding" class="smpl">Content-Encoding</a> (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.2" title="Content-Encoding">Section&nbsp;10.6</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding
     3052      <div id="rfc.figure.u.56"></div><pre class="inline"><span id="rfc.iref.g.52"></span>  <a href="#content.codings" class="smpl">content-coding</a>   = <a href="#imported.abnf" class="smpl">token</a>
     3053</pre><p id="rfc.section.9.4.p.3">All content-coding values are case-insensitive. HTTP/1.1 uses content-coding values in the <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.3" title="Accept-Encoding">Section&nbsp;6.3.4</a>) and <a href="#header.content-encoding" class="smpl">Content-Encoding</a> (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.2" title="Content-Encoding">Section&nbsp;3.2.2</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding
    25353054         mechanism will be required to remove the encoding.
    25363055      </p>
    2537       <p id="rfc.section.9.4.p.4">compress<span id="rfc.iref.c.4"></span><span id="rfc.iref.c.5"></span> 
     3056      <p id="rfc.section.9.4.p.4">compress<span id="rfc.iref.c.8"></span><span id="rfc.iref.c.9"></span> 
    25383057      </p>
    25393058      <ul class="empty">
    2540          <li>See <a href="p1-messaging.html#compress.coding" title="Compress Coding">Section 4.2.1</a> of <a href="#Part1" id="rfc.xref.Part1.24"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
    2541          </li>
    2542       </ul>
    2543       <p id="rfc.section.9.4.p.5">deflate<span id="rfc.iref.d.2"></span><span id="rfc.iref.c.6"></span> 
     3059         <li>See <a href="p1-messaging.html#compress.coding" title="Compress Coding">Section 4.2.1</a> of <a href="#Part1" id="rfc.xref.Part1.29"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
     3060         </li>
     3061      </ul>
     3062      <p id="rfc.section.9.4.p.5">deflate<span id="rfc.iref.d.3"></span><span id="rfc.iref.c.10"></span> 
    25443063      </p>
    25453064      <ul class="empty">
    2546          <li>See <a href="p1-messaging.html#deflate.coding" title="Deflate Coding">Section 4.2.2</a> of <a href="#Part1" id="rfc.xref.Part1.25"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
    2547          </li>
    2548       </ul>
    2549       <p id="rfc.section.9.4.p.6">gzip<span id="rfc.iref.g.25"></span><span id="rfc.iref.c.7"></span> 
     3065         <li>See <a href="p1-messaging.html#deflate.coding" title="Deflate Coding">Section 4.2.2</a> of <a href="#Part1" id="rfc.xref.Part1.30"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
     3066         </li>
     3067      </ul>
     3068      <p id="rfc.section.9.4.p.6">gzip<span id="rfc.iref.g.53"></span><span id="rfc.iref.c.11"></span> 
    25503069      </p>
    25513070      <ul class="empty">
    2552          <li>See <a href="p1-messaging.html#gzip.coding" title="Gzip Coding">Section 4.2.3</a> of <a href="#Part1" id="rfc.xref.Part1.26"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
     3071         <li>See <a href="p1-messaging.html#gzip.coding" title="Gzip Coding">Section 4.2.3</a> of <a href="#Part1" id="rfc.xref.Part1.31"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
    25533072         </li>
    25543073      </ul>
    25553074      <h2 id="rfc.section.9.5"><a href="#rfc.section.9.5">9.5</a>&nbsp;<a id="media.types" href="#media.types">Media Types</a></h2>
    2556       <p id="rfc.section.9.5.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> in the <a href="#header.content-type" class="smpl">Content-Type</a> (<a href="#header.content-type" id="rfc.xref.header.content-type.3" title="Content-Type">Section&nbsp;10.9</a>) and <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section&nbsp;10.1</a>) header fields in order to provide open and extensible data typing and type negotiation.
    2557       </p>
    2558       <div id="rfc.figure.u.18"></div><pre class="inline"><span id="rfc.iref.g.26"></span><span id="rfc.iref.g.27"></span><span id="rfc.iref.g.28"></span>  <a href="#media.types" class="smpl">media-type</a> = <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> *( <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> )
     3075      <p id="rfc.section.9.5.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> in the <a href="#header.content-type" class="smpl">Content-Type</a> (<a href="#header.content-type" id="rfc.xref.header.content-type.3" title="Content-Type">Section&nbsp;3.2.1</a>) and <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section&nbsp;6.3.2</a>) header fields in order to provide open and extensible data typing and type negotiation.
     3076      </p>
     3077      <div id="rfc.figure.u.57"></div><pre class="inline"><span id="rfc.iref.g.54"></span><span id="rfc.iref.g.55"></span><span id="rfc.iref.g.56"></span>  <a href="#media.types" class="smpl">media-type</a> = <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> *( <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> )
    25593078  <a href="#media.types" class="smpl">type</a>       = <a href="#imported.abnf" class="smpl">token</a>
    25603079  <a href="#media.types" class="smpl">subtype</a>    = <a href="#imported.abnf" class="smpl">token</a>
    … …  
    25633082         </p>
    25643083      </div>
    2565       <div id="rfc.figure.u.19"></div><pre class="inline"><span id="rfc.iref.g.29"></span><span id="rfc.iref.g.30"></span><span id="rfc.iref.g.31"></span>  <a href="#rule.parameter" class="smpl">parameter</a>      = <a href="#rule.parameter" class="smpl">attribute</a> "=" <a href="#rule.parameter" class="smpl">value</a>
     3084      <div id="rfc.figure.u.58"></div><pre class="inline"><span id="rfc.iref.g.57"></span><span id="rfc.iref.g.58"></span><span id="rfc.iref.g.59"></span>  <a href="#rule.parameter" class="smpl">parameter</a>      = <a href="#rule.parameter" class="smpl">attribute</a> "=" <a href="#rule.parameter" class="smpl">value</a>
    25663085  <a href="#rule.parameter" class="smpl">attribute</a>      = <a href="#imported.abnf" class="smpl">token</a>
    25673086  <a href="#rule.parameter" class="smpl">value</a>          = <a href="#imported.abnf" class="smpl">word</a>
    … …  
    26133132         of subtags:
    26143133      </p>
    2615       <div id="rfc.figure.u.20"></div><pre class="inline"><span id="rfc.iref.g.32"></span>  <a href="#language.tags" class="smpl">language-tag</a> = &lt;Language-Tag, defined in <a href="#RFC5646" id="rfc.xref.RFC5646.2"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, <a href="http://tools.ietf.org/html/rfc5646#section-2.1">Section 2.1</a>&gt;
     3134      <div id="rfc.figure.u.59"></div><pre class="inline"><span id="rfc.iref.g.60"></span>  <a href="#language.tags" class="smpl">language-tag</a> = &lt;Language-Tag, defined in <a href="#RFC5646" id="rfc.xref.RFC5646.2"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, <a href="http://tools.ietf.org/html/rfc5646#section-2.1">Section 2.1</a>&gt;
    26163135</pre><p id="rfc.section.9.6.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered
    26173136         by the IANA (see &lt;<a href="http://www.iana.org/assignments/language-subtag-registry">http://www.iana.org/assignments/language-subtag-registry</a>&gt;).
    26183137      </p>
    2619       <div id="rfc.figure.u.21"></div>
     3138      <div id="rfc.figure.u.60"></div>
    26203139      <p>Example tags include:</p>  <pre class="text">  en, en-US, es-419, az-Arab, x-pig-latin, man-Nkoo-GN
    26213140</pre> <p id="rfc.section.9.6.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information.
    26223141      </p>
    2623       <h1 id="rfc.section.10"><a href="#rfc.section.10">10.</a>&nbsp;<a id="header.field.definitions" href="#header.field.definitions">Header Field Definitions</a></h1>
    2624       <p id="rfc.section.10.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to request and response semantics and to the
    2625          payload of messages.
    2626       </p>
    2627       <div id="rfc.iref.a.1"></div>
    2628       <div id="rfc.iref.h.2"></div>
    2629       <h2 id="rfc.section.10.1"><a href="#rfc.section.10.1">10.1</a>&nbsp;<a id="header.accept" href="#header.accept">Accept</a></h2>
    2630       <p id="rfc.section.10.1.p.1">The "Accept" header field can be used by user agents to specify response media types that are acceptable. Accept header fields
    2631          can be used to indicate that the request is specifically limited to a small set of desired types, as in the case of a request
    2632          for an in-line image.
    2633       </p>
    2634       <div id="rfc.figure.u.22"></div><pre class="inline"><span id="rfc.iref.g.33"></span><span id="rfc.iref.g.34"></span><span id="rfc.iref.g.35"></span><span id="rfc.iref.g.36"></span>  <a href="#header.accept" class="smpl">Accept</a> = #( <a href="#header.accept" class="smpl">media-range</a> [ <a href="#header.accept" class="smpl">accept-params</a> ] )
    2635  
    2636   <a href="#header.accept" class="smpl">media-range</a>    = ( "*/*"
    2637                    / ( <a href="#media.types" class="smpl">type</a> "/" "*" )
    2638                    / ( <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> )
    2639                    ) *( <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> )
    2640   <a href="#header.accept" class="smpl">accept-params</a>  = <a href="#quality.values" class="smpl">weight</a> *( <a href="#header.accept" class="smpl">accept-ext</a> )
    2641   <a href="#header.accept" class="smpl">accept-ext</a>     = <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#imported.abnf" class="smpl">token</a> [ "=" <a href="#imported.abnf" class="smpl">word</a> ]
    2642 </pre><p id="rfc.section.10.1.p.3">The asterisk "*" character is used to group media types into ranges, with "*/*" indicating all media types and "type/*" indicating
    2643          all subtypes of that type. The media-range <em class="bcp14">MAY</em> include media type parameters that are applicable to that range.
    2644       </p>
    2645       <p id="rfc.section.10.1.p.4">Each media-range <em class="bcp14">MAY</em> be followed by one or more accept-params, beginning with the "q" parameter for indicating a relative weight, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;3.4.3</a>. The first "q" parameter (if any) separates the media-range parameter(s) from the accept-params.
    2646       </p>
    2647       <div class="note" id="rfc.section.10.1.p.5">
    2648          <p> <b>Note:</b> Use of the "q" parameter name to separate media type parameters from Accept extension parameters is due to historical practice.
    2649             Although this prevents any media type parameter named "q" from being used with a media range, such an event is believed to
    2650             be unlikely given the lack of any "q" parameters in the IANA media type registry and the rare usage of any media type parameters
    2651             in Accept. Future media types are discouraged from registering any parameter named "q".
    2652          </p>
    2653       </div>
    2654       <p id="rfc.section.10.1.p.6">The example</p>
    2655       <div id="rfc.figure.u.23"></div><pre class="text">  Accept: audio/*; q=0.2, audio/basic
    2656 </pre><p id="rfc.section.10.1.p.8"> <em class="bcp14">SHOULD</em> be interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% mark-down in
    2657          quality".
    2658       </p>
    2659       <p id="rfc.section.10.1.p.9">A request without any Accept header field implies that the user agent will accept any media type in response. If an Accept
    2660          header field is present in a request and none of the available representations for the response have a media type that is
    2661          listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept header field by sending a <a href="#status.406" class="smpl">406 (Not Acceptable)</a> response or disregard the Accept header field by treating the response as if it is not subject to content negotiation.
    2662       </p>
    2663       <p id="rfc.section.10.1.p.10">A more elaborate example is</p>
    2664       <div id="rfc.figure.u.24"></div><pre class="text">  Accept: text/plain; q=0.5, text/html,
    2665           text/x-dvi; q=0.8, text/x-c
    2666 </pre><p id="rfc.section.10.1.p.12">Verbally, this would be interpreted as "text/html and text/x-c are the preferred media types, but if they do not exist, then
    2667          send the text/x-dvi representation, and if that does not exist, send the text/plain representation".
    2668       </p>
    2669       <p id="rfc.section.10.1.p.13">Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies
    2670          to a given type, the most specific reference has precedence. For example,
    2671       </p>
    2672       <div id="rfc.figure.u.25"></div><pre class="text">  Accept: text/*, text/plain, text/plain;format=flowed, */*
    2673 </pre><p id="rfc.section.10.1.p.15">have the following precedence: </p>
    2674       <ol>
    2675          <li>text/plain;format=flowed</li>
    2676          <li>text/plain</li>
    2677          <li>text/*</li>
    2678          <li>*/*</li>
    2679       </ol>
    2680       <p id="rfc.section.10.1.p.16">The media type quality factor associated with a given type is determined by finding the media range with the highest precedence
    2681          which matches that type. For example,
    2682       </p>
    2683       <div id="rfc.figure.u.26"></div><pre class="text">  Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1,
    2684           text/html;level=2;q=0.4, */*;q=0.5
    2685 </pre><p id="rfc.section.10.1.p.18">would cause the following values to be associated:</p>
    2686       <div id="rfc.table.u.14">
    2687          <table class="tt full left" cellpadding="3" cellspacing="0">
    2688             <thead>
    2689                <tr>
    2690                   <th>Media Type</th>
    2691                   <th>Quality Value</th>
    2692                </tr>
    2693             </thead>
    2694             <tbody>
    2695                <tr>
    2696                   <td class="left">text/html;level=1</td>
    2697                   <td class="left">1</td>
    2698                </tr>
    2699                <tr>
    2700                   <td class="left">text/html</td>
    2701                   <td class="left">0.7</td>
    2702                </tr>
    2703                <tr>
    2704                   <td class="left">text/plain</td>
    2705                   <td class="left">0.3</td>
    2706                </tr>
    2707                <tr>
    2708                   <td class="left">image/jpeg</td>
    2709                   <td class="left">0.5</td>
    2710                </tr>
    2711                <tr>
    2712                   <td class="left">text/html;level=2</td>
    2713                   <td class="left">0.4</td>
    2714                </tr>
    2715                <tr>
    2716                   <td class="left">text/html;level=3</td>
    2717                   <td class="left">0.7</td>
    2718                </tr>
    2719             </tbody>
    2720          </table>
    2721       </div>
    2722       <p id="rfc.section.10.1.p.19"> <b>Note:</b> A user agent might be provided with a default set of quality values for certain media ranges. However, unless the user agent
    2723          is a closed system which cannot interact with other rendering agents, this default set ought to be configurable by the user.
    2724       </p>
    2725       <div id="rfc.iref.a.2"></div>
    2726       <div id="rfc.iref.h.3"></div>
    2727       <h2 id="rfc.section.10.2"><a href="#rfc.section.10.2">10.2</a>&nbsp;<a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h2>
    2728       <p id="rfc.section.10.2.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response
    2729          payload. This field allows clients capable of understanding more comprehensive or special-purpose character encodings to signal
    2730          that capability to a server which is capable of representing documents in those character encodings.
    2731       </p>
    2732       <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.37"></span>  <a href="#header.accept-charset" class="smpl">Accept-Charset</a> = 1#( ( <a href="#rule.charset" class="smpl">charset</a> / "*" ) [ <a href="#quality.values" class="smpl">weight</a> ] )
    2733 </pre><p id="rfc.section.10.2.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section&nbsp;9.3</a>. Each charset <em class="bcp14">MAY</em> be given an associated quality value which represents the user's preference for that charset, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;3.4.3</a>. An example is
    2734       </p>
    2735       <div id="rfc.figure.u.28"></div><pre class="text">  Accept-Charset: iso-8859-5, unicode-1-1;q=0.8
    2736 </pre><p id="rfc.section.10.2.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere
    2737          in the Accept-Charset field. If no "*" is present in an Accept-Charset field, then any character encodings not explicitly
    2738          mentioned in the field are considered "not acceptable" to the client.
    2739       </p>
    2740       <p id="rfc.section.10.2.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response.</p>
    2741       <p id="rfc.section.10.2.p.7">If an Accept-Charset header field is present in a request and none of the available representations for the response have
    2742          a character encoding that is listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept-Charset header field by sending a <a href="#status.406" class="smpl">406 (Not Acceptable)</a> response or disregard the Accept-Charset header field by treating the response as if it is not subject to content negotiation.
    2743       </p>
    2744       <div id="rfc.iref.a.3"></div>
    2745       <div id="rfc.iref.h.4"></div>
    2746       <h2 id="rfc.section.10.3"><a href="#rfc.section.10.3">10.3</a>&nbsp;<a id="header.accept-encoding" href="#header.accept-encoding">Accept-Encoding</a></h2>
    2747       <p id="rfc.section.10.3.p.1">The "Accept-Encoding" header field can be used by user agents to indicate what response content-codings (<a href="#content.codings" title="Content Codings">Section&nbsp;9.4</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when
    2748          no encoding is preferred.
    2749       </p>
    2750       <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.38"></span><span id="rfc.iref.g.39"></span>  <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a>  = #( <a href="#header.accept-encoding" class="smpl">codings</a> [ <a href="#quality.values" class="smpl">weight</a> ] )
    2751   <a href="#header.accept-encoding" class="smpl">codings</a>          = <a href="#content.codings" class="smpl">content-coding</a> / "identity" / "*"
    2752 </pre><p id="rfc.section.10.3.p.3">Each codings value <em class="bcp14">MAY</em> be given an associated quality value which represents the preference for that encoding, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;3.4.3</a>.
    2753       </p>
    2754       <p id="rfc.section.10.3.p.4">For example,</p>
    2755       <div id="rfc.figure.u.30"></div><pre class="text">  Accept-Encoding: compress, gzip
    2756   Accept-Encoding:
    2757   Accept-Encoding: *
    2758   Accept-Encoding: compress;q=0.5, gzip;q=1.0
    2759   Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0
    2760 </pre><p id="rfc.section.10.3.p.6">A server tests whether a content-coding for a given representation is acceptable, according to an Accept-Encoding field, using
    2761          these rules:
    2762       </p>
    2763       <ol>
    2764          <li>The special "*" symbol in an Accept-Encoding field matches any available content-coding not explicitly listed in the header
    2765             field.
    2766          </li>
    2767          <li>If the representation has no content-coding, then it is acceptable by default unless specifically excluded by the Accept-Encoding
    2768             field stating either "identity;q=0" or "*;q=0" without a more specific entry for "identity".
    2769          </li>
    2770          <li>If the representation's content-coding is one of the content-codings listed in the Accept-Encoding field, then it is acceptable
    2771             unless it is accompanied by a qvalue of 0. (As defined in <a href="#quality.values" title="Quality Values">Section&nbsp;3.4.3</a>, a qvalue of 0 means "not acceptable".)
    2772          </li>
    2773          <li>If multiple content-codings are acceptable, then the acceptable content-coding with the highest non-zero qvalue is preferred.</li>
    2774       </ol>
    2775       <p id="rfc.section.10.3.p.7">An Accept-Encoding header field with a combined field-value that is empty implies that the user agent does not want any content-coding
    2776          in response. If an Accept-Encoding header field is present in a request and none of the available representations for the
    2777          response have a content-coding that is listed as acceptable, the origin server <em class="bcp14">SHOULD</em> send a response without any content-coding.
    2778       </p>
    2779       <p id="rfc.section.10.3.p.8">A request without an Accept-Encoding header field implies that the user agent will accept any content-coding in response.</p>
    2780       <div class="note" id="rfc.section.10.3.p.9">
    2781          <p> <b>Note:</b> Most HTTP/1.0 applications do not recognize or obey qvalues associated with content-codings. This means that qvalues will
    2782             not work and are not permitted with x-gzip or x-compress.
    2783          </p>
    2784       </div>
    2785       <div id="rfc.iref.a.4"></div>
    2786       <div id="rfc.iref.h.5"></div>
    2787       <h2 id="rfc.section.10.4"><a href="#rfc.section.10.4">10.4</a>&nbsp;<a id="header.accept-language" href="#header.accept-language">Accept-Language</a></h2>
    2788       <p id="rfc.section.10.4.p.1">The "Accept-Language" header field can be used by user agents to indicate the set of natural languages that are preferred
    2789          in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;9.6</a>.
    2790       </p>
    2791       <div id="rfc.figure.u.31"></div><pre class="inline"><span id="rfc.iref.g.40"></span><span id="rfc.iref.g.41"></span>  <a href="#header.accept-language" class="smpl">Accept-Language</a> = 1#( <a href="#header.accept-language" class="smpl">language-range</a> [ <a href="#quality.values" class="smpl">weight</a> ] )
    2792   <a href="#header.accept-language" class="smpl">language-range</a>  =
    2793             &lt;language-range, defined in <a href="#RFC4647" id="rfc.xref.RFC4647.1"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-2.1">Section 2.1</a>&gt;
    2794 </pre><p id="rfc.section.10.4.p.3">Each language-range can be given an associated quality value which represents an estimate of the user's preference for the
    2795          languages specified by that range, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;3.4.3</a>. For example,
    2796       </p>
    2797       <div id="rfc.figure.u.32"></div><pre class="text">  Accept-Language: da, en-gb;q=0.8, en;q=0.7
    2798 </pre><p id="rfc.section.10.4.p.5">would mean: "I prefer Danish, but will accept British English and other types of English". (see also <a href="http://tools.ietf.org/html/rfc4647#section-2.3">Section 2.3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.2"><cite title="Matching of Language Tags">[RFC4647]</cite></a>)
    2799       </p>
    2800       <p id="rfc.section.10.4.p.6">For matching, <a href="http://tools.ietf.org/html/rfc4647#section-3">Section 3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.3"><cite title="Matching of Language Tags">[RFC4647]</cite></a> defines several matching schemes. Implementations can offer the most appropriate matching scheme for their requirements.
    2801       </p>
    2802       <div class="note" id="rfc.section.10.4.p.7">
    2803          <p> <b>Note:</b> The "Basic Filtering" scheme (<a href="#RFC4647" id="rfc.xref.RFC4647.4"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-3.3.1">Section 3.3.1</a>) is identical to the matching scheme that was previously defined in <a href="http://tools.ietf.org/html/rfc2616#section-14.4">Section 14.4</a> of <a href="#RFC2616" id="rfc.xref.RFC2616.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>.
    2804          </p>
    2805       </div>
    2806       <p id="rfc.section.10.4.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic
    2807          preferences of the user in every request. For a discussion of this issue, see <a href="#privacy.issues.connected.to.accept.header.fields" title="Privacy Issues Connected to Accept Header Fields">Section&nbsp;12.5</a>.
    2808       </p>
    2809       <p id="rfc.section.10.4.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice
    2810          of linguistic preference available to the user. If the choice is not made available, then the Accept-Language header field <em class="bcp14">MUST NOT</em> be given in the request.
    2811       </p>
    2812       <div class="note" id="rfc.section.10.4.p.10">
    2813          <p> <b>Note:</b> When making the choice of linguistic preference available to the user, we remind implementers of the fact that users are not
    2814             familiar with the details of language matching as described above, and ought to be provided appropriate guidance. As an example,
    2815             users might assume that on selecting "en-gb", they will be served any kind of English document if British English is not available.
    2816             A user agent might suggest in such a case to add "en" to get the best matching behavior.
    2817          </p>
    2818       </div>
    2819       <div id="rfc.iref.a.5"></div>
    2820       <div id="rfc.iref.h.6"></div>
    2821       <h2 id="rfc.section.10.5"><a href="#rfc.section.10.5">10.5</a>&nbsp;<a id="header.allow" href="#header.allow">Allow</a></h2>
    2822       <p id="rfc.section.10.5.p.1">The "Allow" header field lists the set of methods advertised as supported by the target resource. The purpose of this field
    2823          is strictly to inform the recipient of valid request methods associated with the resource.
    2824       </p>
    2825       <div id="rfc.figure.u.33"></div><pre class="inline"><span id="rfc.iref.g.42"></span>  <a href="#header.allow" class="smpl">Allow</a> = #<a href="#method.overview" class="smpl">method</a>
    2826 </pre><p id="rfc.section.10.5.p.3">Example of use:</p>
    2827       <div id="rfc.figure.u.34"></div><pre class="text">  Allow: GET, HEAD, PUT
    2828 </pre><p id="rfc.section.10.5.p.5">The actual set of allowed methods is defined by the origin server at the time of each request.</p>
    2829       <p id="rfc.section.10.5.p.6">A proxy <em class="bcp14">MUST NOT</em> modify the Allow header field — it does not need to understand all the methods specified in order to handle them according
    2830          to the generic message handling rules.
    2831       </p>
    2832       <div id="rfc.iref.c.8"></div>
    2833       <div id="rfc.iref.h.7"></div>
    2834       <h2 id="rfc.section.10.6"><a href="#rfc.section.10.6">10.6</a>&nbsp;<a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h2>
    2835       <p id="rfc.section.10.6.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent
    2836          in the media type, and thus what decoding mechanisms have to be applied in order to obtain the media-type referenced by the <a href="#header.content-type" class="smpl">Content-Type</a> header field. Content-Encoding is primarily used to allow a representation to be compressed without losing the identity of
    2837          its underlying media type.
    2838       </p>
    2839       <div id="rfc.figure.u.35"></div><pre class="inline"><span id="rfc.iref.g.43"></span>  <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = 1#<a href="#content.codings" class="smpl">content-coding</a>
    2840 </pre><p id="rfc.section.10.6.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section&nbsp;9.4</a>. An example of its use is
    2841       </p>
    2842       <div id="rfc.figure.u.36"></div><pre class="text">  Content-Encoding: gzip
    2843 </pre><p id="rfc.section.10.6.p.5">The content-coding is a characteristic of the representation. Typically, the representation body is stored with this encoding
    2844          and is only decoded before rendering or analogous usage. However, a transforming proxy <em class="bcp14">MAY</em> modify the content-coding if the new coding is known to be acceptable to the recipient, unless the "no-transform" cache-control
    2845          directive is present in the message.
    2846       </p>
    2847       <p id="rfc.section.10.6.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would
    2848          not be restated as a Content-Encoding even if it happens to be the same algorithm as one of the content-codings. Such a content-coding
    2849          would only be listed if, for some bizarre reason, it is applied a second time to form the representation. Likewise, an origin
    2850          server might choose to publish the same payload data as multiple representations that differ only in whether the coding is
    2851          defined as part of <a href="#header.content-type" class="smpl">Content-Type</a> or Content-Encoding, since some user agents will behave differently in their handling of each response (e.g., open a "Save
    2852          as ..." dialog instead of automatic decompression and rendering of content).
    2853       </p>
    2854       <p id="rfc.section.10.6.p.7">A representation that has a content-coding applied to it <em class="bcp14">MUST</em> include a Content-Encoding header field that lists the content-coding(s) applied.
    2855       </p>
    2856       <p id="rfc.section.10.6.p.8">If multiple encodings have been applied to a representation, the content codings <em class="bcp14">MUST</em> be listed in the order in which they were applied. Additional information about the encoding parameters <em class="bcp14">MAY</em> be provided by other header fields not defined by this specification.
    2857       </p>
    2858       <p id="rfc.section.10.6.p.9">If the content-coding of a representation in a request message is not acceptable to the origin server, the server <em class="bcp14">SHOULD</em> respond with a status code of 415 (Unsupported Media Type).
    2859       </p>
    2860       <div id="rfc.iref.c.9"></div>
    2861       <div id="rfc.iref.h.8"></div>
    2862       <h2 id="rfc.section.10.7"><a href="#rfc.section.10.7">10.7</a>&nbsp;<a id="header.content-language" href="#header.content-language">Content-Language</a></h2>
    2863       <p id="rfc.section.10.7.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note
    2864          that this might not be equivalent to all the languages used within the representation.
    2865       </p>
    2866       <div id="rfc.figure.u.37"></div><pre class="inline"><span id="rfc.iref.g.44"></span>  <a href="#header.content-language" class="smpl">Content-Language</a> = 1#<a href="#language.tags" class="smpl">language-tag</a>
    2867 </pre><p id="rfc.section.10.7.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;9.6</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the
    2868          user's own preferred language. Thus, if the body content is intended only for a Danish-literate audience, the appropriate
    2869          field is
    2870       </p>
    2871       <div id="rfc.figure.u.38"></div><pre class="text">  Content-Language: da
    2872 </pre><p id="rfc.section.10.7.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean
    2873          that the sender does not consider it to be specific to any natural language, or that the sender does not know for which language
    2874          it is intended.
    2875       </p>
    2876       <p id="rfc.section.10.7.p.6">Multiple languages <em class="bcp14">MAY</em> be listed for content that is intended for multiple audiences. For example, a rendition of the "Treaty of Waitangi", presented
    2877          simultaneously in the original Maori and English versions, would call for
    2878       </p>
    2879       <div id="rfc.figure.u.39"></div><pre class="text">  Content-Language: mi, en
    2880 </pre><p id="rfc.section.10.7.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple
    2881          linguistic audiences. An example would be a beginner's language primer, such as "A First Lesson in Latin", which is clearly
    2882          intended to be used by an English-literate audience. In this case, the Content-Language would properly only include "en".
    2883       </p>
    2884       <p id="rfc.section.10.7.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents.
    2885       </p>
    2886       <div id="rfc.iref.c.10"></div>
    2887       <div id="rfc.iref.h.9"></div>
    2888       <h2 id="rfc.section.10.8"><a href="#rfc.section.10.8">10.8</a>&nbsp;<a id="header.content-location" href="#header.content-location">Content-Location</a></h2>
    2889       <p id="rfc.section.10.8.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this
    2890          message. In other words, if one were to perform a GET on this URI at the time of this message's generation, then a <a href="#status.200" class="smpl">200 (OK)</a> response would contain the same representation that is enclosed as payload in this message.
    2891       </p>
    2892       <div id="rfc.figure.u.40"></div><pre class="inline"><span id="rfc.iref.g.45"></span>  <a href="#header.content-location" class="smpl">Content-Location</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a>
    2893 </pre><p id="rfc.section.10.8.p.3">The Content-Location value is not a replacement for the effective Request URI (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.27"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>). It is representation metadata. It has the same syntax and semantics as the header field of the same name defined for MIME
    2894          body parts in <a href="http://tools.ietf.org/html/rfc2557#section-4">Section 4</a> of <a href="#RFC2557" id="rfc.xref.RFC2557.1"><cite title="MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)">[RFC2557]</cite></a>. However, its appearance in an HTTP message has some special implications for HTTP recipients.
    2895       </p>
    2896       <p id="rfc.section.10.8.p.4">If Content-Location is included in a response message and its value is the same as the effective request URI, then the response
    2897          payload <em class="bcp14">SHOULD</em> be considered a current representation of that resource. For a GET or HEAD request, this is the same as the default semantics
    2898          when no Content-Location is provided by the server. For a state-changing request like PUT or POST, it implies that the server's
    2899          response contains the new representation of that resource, thereby distinguishing it from representations that might only
    2900          report about the action (e.g., "It worked!"). This allows authoring applications to update their local copies without the
    2901          need for a subsequent GET request.
    2902       </p>
    2903       <p id="rfc.section.10.8.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin
    2904          server is informing recipients that this representation has its own, presumably more specific, identifier. For a GET or HEAD
    2905          request, this is an indication that the effective request URI identifies a resource that is subject to content negotiation
    2906          and the selected representation for this response can also be found at the identified URI. For other methods, such a Content-Location
    2907          indicates that this representation contains a report on the action's status and the same report is available (for future access
    2908          with GET) at the given URI. For example, a purchase transaction made via a POST request might include a receipt document as
    2909          the payload of the <a href="#status.200" class="smpl">200 (OK)</a> response; the Content-Location value provides an identifier for retrieving a copy of that same receipt in the future.
    2910       </p>
    2911       <p id="rfc.section.10.8.p.6">If Content-Location is included in a request message, then it <em class="bcp14">MAY</em> be interpreted by the origin server as an indication of where the user agent originally obtained the content of the enclosed
    2912          representation (prior to any subsequent modification of the content by that user agent). In other words, the user agent is
    2913          providing the same representation metadata that it received with the original representation. However, such interpretation <em class="bcp14">MUST NOT</em> be used to alter the semantics of the method requested by the client. For example, if a client makes a PUT request on a negotiated
    2914          resource and the origin server accepts that PUT (without redirection), then the new set of values for that resource is expected
    2915          to be consistent with the one representation supplied in that PUT; the Content-Location cannot be used as a form of reverse
    2916          content selection that identifies only one of the negotiated representations to be updated. If the user agent had wanted the
    2917          latter semantics, it would have applied the PUT directly to the Content-Location URI.
    2918       </p>
    2919       <p id="rfc.section.10.8.p.7">A Content-Location field received in a request message is transitory information that <em class="bcp14">SHOULD NOT</em> be saved with other representation metadata for use in later responses. The Content-Location's value might be saved for use
    2920          in other contexts, such as within source links or other metadata.
    2921       </p>
    2922       <p id="rfc.section.10.8.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used
    2923          to respond to later requests on that Content-Location URI.
    2924       </p>
    2925       <p id="rfc.section.10.8.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p>
    2926       <div id="rfc.iref.c.11"></div>
    2927       <div id="rfc.iref.h.10"></div>
    2928       <h2 id="rfc.section.10.9"><a href="#rfc.section.10.9">10.9</a>&nbsp;<a id="header.content-type" href="#header.content-type">Content-Type</a></h2>
    2929       <p id="rfc.section.10.9.p.1">The "Content-Type" header field indicates the media type of the representation. In the case of responses to the HEAD method,
    2930          the media type is that which would have been sent had the request been a GET.
    2931       </p>
    2932       <div id="rfc.figure.u.41"></div><pre class="inline"><span id="rfc.iref.g.46"></span>  <a href="#header.content-type" class="smpl">Content-Type</a> = <a href="#media.types" class="smpl">media-type</a>
    2933 </pre><p id="rfc.section.10.9.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section&nbsp;9.5</a>. An example of the field is
    2934       </p>
    2935       <div id="rfc.figure.u.42"></div><pre class="text">  Content-Type: text/html; charset=ISO-8859-4
    2936 </pre><p id="rfc.section.10.9.p.5">Further discussion of Content-Type is provided in <a href="#representation.data" title="Representation Data">Section&nbsp;3.3</a>.
    2937       </p>
    2938       <div id="rfc.iref.d.3"></div>
    2939       <div id="rfc.iref.h.11"></div>
    2940       <h2 id="rfc.section.10.10"><a href="#rfc.section.10.10">10.10</a>&nbsp;<a id="header.date" href="#header.date">Date</a></h2>
    2941       <p id="rfc.section.10.10.p.1">The "Date" header field represents the date and time at which the message was originated, having the same semantics as the
    2942          Origination Date Field (orig-date) defined in <a href="http://tools.ietf.org/html/rfc5322#section-3.6.1">Section 3.6.1</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.2"><cite title="Internet Message Format">[RFC5322]</cite></a>. The field value is an HTTP-date, as defined in <a href="#http.date" title="Date/Time Formats">Section&nbsp;9.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.
    2943       </p>
    2944       <div id="rfc.figure.u.43"></div><pre class="inline"><span id="rfc.iref.g.47"></span>  <a href="#header.date" class="smpl">Date</a> = <a href="#http.date" class="smpl">HTTP-date</a>
    2945 </pre><p id="rfc.section.10.10.p.3">An example is</p>
    2946       <div id="rfc.figure.u.44"></div><pre class="text">  Date: Tue, 15 Nov 1994 08:12:31 GMT
    2947 </pre><p id="rfc.section.10.10.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:
    2948       </p>
    2949       <ol>
    2950          <li>If the response status code is <a href="#status.100" class="smpl">100 (Continue)</a> or <a href="#status.101" class="smpl">101 (Switching Protocols)</a>, the response <em class="bcp14">MAY</em> include a Date header field, at the server's option.
    2951          </li>
    2952          <li>If the response status code conveys a server error, e.g., <a href="#status.500" class="smpl">500
    2953                (Internal Server Error)</a> or <a href="#status.503" class="smpl">503 (Service Unavailable)</a>, and it is inconvenient or impossible to generate a valid Date.
    2954          </li>
    2955          <li>If the server does not have a clock that can provide a reasonable approximation of the current time, its responses <em class="bcp14">MUST NOT</em> include a Date header field.
    2956          </li>
    2957       </ol>
    2958       <p id="rfc.section.10.10.p.6">A received message that does not have a Date header field <em class="bcp14">MUST</em> be assigned one by the recipient if the message will be cached by that recipient.
    2959       </p>
    2960       <p id="rfc.section.10.10.p.7">Clients can use the Date header field as well; in order to keep request messages small, they are advised not to include it
    2961          when it doesn't convey any useful information (as is usually the case for requests that do not contain a payload).
    2962       </p>
    2963       <p id="rfc.section.10.10.p.8">The HTTP-date sent in a Date header field <em class="bcp14">SHOULD NOT</em> represent a date and time subsequent to the generation of the message. It <em class="bcp14">SHOULD</em> represent the best available approximation of the date and time of message generation, unless the implementation has no means
    2964          of generating a reasonably accurate date and time. In theory, the date ought to represent the moment just before the payload
    2965          is generated. In practice, the date can be generated at any time during the message origination without affecting its semantic
    2966          value.
    2967       </p>
    2968       <div id="rfc.iref.e.1"></div>
    2969       <div id="rfc.iref.h.12"></div>
    2970       <h2 id="rfc.section.10.11"><a href="#rfc.section.10.11">10.11</a>&nbsp;<a id="header.expect" href="#header.expect">Expect</a></h2>
    2971       <p id="rfc.section.10.11.p.1">The "Expect" header field is used to indicate that particular server behaviors are required by the client.</p>
    2972       <div id="rfc.figure.u.45"></div><pre class="inline"><span id="rfc.iref.g.48"></span><span id="rfc.iref.g.49"></span><span id="rfc.iref.g.50"></span><span id="rfc.iref.g.51"></span><span id="rfc.iref.g.52"></span>  <a href="#header.expect" class="smpl">Expect</a>       = 1#<a href="#header.expect" class="smpl">expectation</a>
    2973  
    2974   <a href="#header.expect" class="smpl">expectation</a>  = <a href="#header.expect" class="smpl">expect-name</a> [ <a href="#imported.abnf" class="smpl">BWS</a> "=" <a href="#imported.abnf" class="smpl">BWS</a> <a href="#header.expect" class="smpl">expect-value</a> ]
    2975                              *( <a href="#imported.abnf" class="smpl">OWS</a> ";" [ <a href="#imported.abnf" class="smpl">OWS</a> <a href="#header.expect" class="smpl">expect-param</a> ] )
    2976   <a href="#header.expect" class="smpl">expect-param</a> = <a href="#header.expect" class="smpl">expect-name</a> [ <a href="#imported.abnf" class="smpl">BWS</a> "=" <a href="#imported.abnf" class="smpl">BWS</a> <a href="#header.expect" class="smpl">expect-value</a> ]
    2977  
    2978   <a href="#header.expect" class="smpl">expect-name</a>  = <a href="#imported.abnf" class="smpl">token</a>
    2979   <a href="#header.expect" class="smpl">expect-value</a> = <a href="#imported.abnf" class="smpl">token</a> / <a href="#imported.abnf" class="smpl">quoted-string</a>
    2980 </pre><p id="rfc.section.10.11.p.3">If all received Expect header field(s) are syntactically valid but contain an expectation that the recipient does not understand
    2981          or cannot comply with, the recipient <em class="bcp14">MUST</em> respond with a <a href="#status.417" class="smpl">417 (Expectation Failed)</a> status code. A recipient of a syntactically invalid Expectation header field <em class="bcp14">MUST</em> respond with a <a href="#status.4xx" class="smpl">4xx</a> status code other than 417.
    2982       </p>
    2983       <p id="rfc.section.10.11.p.4">The only expectation defined by this specification is:</p>
    2984       <p id="rfc.section.10.11.p.5"><span id="rfc.iref.142"></span><span id="rfc.iref.e.2"></span> 100-continue
    2985       </p>
    2986       <ul class="empty">
    2987          <li>The "100-continue" expectation is defined <a href="p1-messaging.html#use.of.the.100.status" title="Use of the 100 (Continue) Status">Section 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.28"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>. It does not support any expect-params.
    2988          </li>
    2989       </ul>
    2990       <p id="rfc.section.10.11.p.6">Comparison is case-insensitive for names (expect-name), and case-sensitive for values (expect-value).</p>
    2991       <p id="rfc.section.10.11.p.7">The Expect mechanism is hop-by-hop: the above requirements apply to any server, including proxies. However, the Expect header
    2992          field itself is end-to-end; it <em class="bcp14">MUST</em> be forwarded if the request is forwarded.
    2993       </p>
    2994       <p id="rfc.section.10.11.p.8">Many older HTTP/1.0 and HTTP/1.1 applications do not understand the Expect header field.</p>
    2995       <div id="rfc.iref.f.1"></div>
    2996       <div id="rfc.iref.h.13"></div>
    2997       <h2 id="rfc.section.10.12"><a href="#rfc.section.10.12">10.12</a>&nbsp;<a id="header.from" href="#header.from">From</a></h2>
    2998       <p id="rfc.section.10.12.p.1">The "From" header field, if given, <em class="bcp14">SHOULD</em> contain an Internet e-mail address for the human user who controls the requesting user agent. The address <em class="bcp14">SHOULD</em> be machine-usable, as defined by "mailbox" in <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.3"><cite title="Internet Message Format">[RFC5322]</cite></a>:
    2999       </p>
    3000       <div id="rfc.figure.u.46"></div><pre class="inline"><span id="rfc.iref.g.53"></span>  <a href="#header.from" class="smpl">From</a>    = <a href="#header.from" class="smpl">mailbox</a>
    3001  
    3002   <a href="#header.from" class="smpl">mailbox</a> = &lt;mailbox, defined in <a href="#RFC5322" id="rfc.xref.RFC5322.4"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a>&gt;
    3003 </pre><p id="rfc.section.10.12.p.3">An example is:</p>
    3004       <div id="rfc.figure.u.47"></div><pre class="text">  From: webmaster@example.org
    3005 </pre><p id="rfc.section.10.12.p.5">This header field <em class="bcp14">MAY</em> be used for logging purposes and as a means for identifying the source of invalid or unwanted requests. It <em class="bcp14">SHOULD NOT</em> be used as an insecure form of access protection. The interpretation of this field is that the request is being performed
    3006          on behalf of the person given, who accepts responsibility for the method performed. In particular, robot agents <em class="bcp14">SHOULD</em> include this header field so that the person responsible for running the robot can be contacted if problems occur on the receiving
    3007          end.
    3008       </p>
    3009       <p id="rfc.section.10.12.p.6">The Internet e-mail address in this field <em class="bcp14">MAY</em> be separate from the Internet host which issued the request. For example, when a request is passed through a proxy the original
    3010          issuer's address <em class="bcp14">SHOULD</em> be used.
    3011       </p>
    3012       <p id="rfc.section.10.12.p.7">The client <em class="bcp14">SHOULD NOT</em> send the From header field without the user's approval, as it might conflict with the user's privacy interests or their site's
    3013          security policy. It is strongly recommended that the user be able to disable, enable, and modify the value of this field at
    3014          any time prior to a request.
    3015       </p>
    3016       <div id="rfc.iref.l.1"></div>
    3017       <div id="rfc.iref.h.14"></div>
    3018       <h2 id="rfc.section.10.13"><a href="#rfc.section.10.13">10.13</a>&nbsp;<a id="header.location" href="#header.location">Location</a></h2>
    3019       <p id="rfc.section.10.13.p.1">The "Location" header field <em class="bcp14">MAY</em> be sent in responses to refer to a specific resource in accordance with the semantics of the status code.
    3020       </p>
    3021       <div id="rfc.figure.u.48"></div><pre class="inline"><span id="rfc.iref.g.54"></span>  <a href="#header.location" class="smpl">Location</a> = <a href="#imported.abnf" class="smpl">URI-reference</a>
    3022 </pre><p id="rfc.section.10.13.p.3">For <a href="#status.201" class="smpl">201 (Created)</a> responses, the Location is the URI of the new resource which was created by the request. For <a href="#status.3xx" class="smpl">3xx (Redirection)</a> responses, the location <em class="bcp14">SHOULD</em> indicate the server's preferred URI for automatic redirection to the resource.
    3023       </p>
    3024       <p id="rfc.section.10.13.p.4">The field value consists of a single URI-reference. When it has the form of a relative reference (<a href="#RFC3986" id="rfc.xref.RFC3986.1"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-4.2">Section 4.2</a>), the final value is computed by resolving it against the effective request URI (<a href="#RFC3986" id="rfc.xref.RFC3986.2"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-5">Section 5</a>). If the original URI, as navigated to by the user agent, did contain a fragment identifier, and the final value does not,
    3025          then the original URI's fragment identifier is added to the final value.
    3026       </p>
    3027       <div id="rfc.figure.u.49"></div>
    3028       <p>For example, the original URI "http://www.example.org/~tim", combined with a field value given as:</p>  <pre class="text">  Location: /pub/WWW/People.html#tim
    3029 </pre>  <p>would result in a final value of "http://www.example.org/pub/WWW/People.html#tim"</p>
    3030       <div id="rfc.figure.u.50"></div>
    3031       <p>An original URI "http://www.example.org/index.html#larry", combined with a field value given as:</p>  <pre class="text">  Location: http://www.example.net/index.html
    3032 </pre>  <p>would result in a final value of "http://www.example.net/index.html#larry", preserving the original fragment identifier.</p>
    3033       <div class="note" id="rfc.section.10.13.p.7">
    3034          <p> <b>Note:</b> Some recipients attempt to recover from Location fields that are not valid URI references. This specification does not mandate
    3035             or define such processing, but does allow it.
    3036          </p>
    3037       </div>
    3038       <p id="rfc.section.10.13.p.8">There are circumstances in which a fragment identifier in a Location URI would not be appropriate. For instance, when it appears
    3039          in a <a href="#status.201" class="smpl">201
    3040             (Created)</a> response, where the Location header field specifies the URI for the entire created resource.
    3041       </p>
    3042       <div class="note" id="rfc.section.10.13.p.9">
    3043          <p> <b>Note:</b> The <a href="#header.content-location" class="smpl">Content-Location</a> header field (<a href="#header.content-location" id="rfc.xref.header.content-location.3" title="Content-Location">Section&nbsp;10.8</a>) differs from Location in that the Content-Location identifies the most specific resource corresponding to the enclosed representation.
    3044             It is therefore possible for a response to contain header fields for both Location and Content-Location.
    3045          </p>
    3046       </div>
    3047       <div id="rfc.iref.m.9"></div>
    3048       <div id="rfc.iref.h.15"></div>
    3049       <h2 id="rfc.section.10.14"><a href="#rfc.section.10.14">10.14</a>&nbsp;<a id="header.max-forwards" href="#header.max-forwards">Max-Forwards</a></h2>
    3050       <p id="rfc.section.10.14.p.1">The "Max-Forwards" header field provides a mechanism with the TRACE (<a href="#TRACE" id="rfc.xref.TRACE.2" title="TRACE">Section&nbsp;5.3.8</a>) and OPTIONS (<a href="#OPTIONS" id="rfc.xref.OPTIONS.2" title="OPTIONS">Section&nbsp;5.3.7</a>) methods to limit the number of times that the request is forwarded by proxies. This can be useful when the client is attempting
    3051          to trace a request which appears to be failing or looping mid-chain.
    3052       </p>
    3053       <div id="rfc.figure.u.51"></div><pre class="inline"><span id="rfc.iref.g.55"></span>  <a href="#header.max-forwards" class="smpl">Max-Forwards</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
    3054 </pre><p id="rfc.section.10.14.p.3">The Max-Forwards value is a decimal integer indicating the remaining number of times this request message can be forwarded.</p>
    3055       <p id="rfc.section.10.14.p.4">Each recipient of a TRACE or OPTIONS request containing a Max-Forwards header field <em class="bcp14">MUST</em> check and update its value prior to forwarding the request. If the received value is zero (0), the recipient <em class="bcp14">MUST NOT</em> forward the request; instead, it <em class="bcp14">MUST</em> respond as the final recipient. If the received Max-Forwards value is greater than zero, then the forwarded message <em class="bcp14">MUST</em> contain an updated Max-Forwards field with a value decremented by one (1).
    3056       </p>
    3057       <p id="rfc.section.10.14.p.5">The Max-Forwards header field <em class="bcp14">MAY</em> be ignored for all other request methods.
    3058       </p>
    3059       <div id="rfc.iref.r.2"></div>
    3060       <div id="rfc.iref.h.16"></div>
    3061       <h2 id="rfc.section.10.15"><a href="#rfc.section.10.15">10.15</a>&nbsp;<a id="header.referer" href="#header.referer">Referer</a></h2>
    3062       <p id="rfc.section.10.15.p.1">The "Referer" [sic] header field allows the client to specify the URI of the resource from which the target URI was obtained
    3063          (the "referrer", although the header field is misspelled.).
    3064       </p>
    3065       <p id="rfc.section.10.15.p.2">The Referer header field allows servers to generate lists of back-links to resources for interest, logging, optimized caching,
    3066          etc. It also allows obsolete or mistyped links to be traced for maintenance. Some servers use Referer as a means of controlling
    3067          where they allow links from (so-called "deep linking"), but legitimate requests do not always contain a Referer header field.
    3068       </p>
    3069       <p id="rfc.section.10.15.p.3">If the target URI was obtained from a source that does not have its own URI (e.g., input from the user keyboard), the Referer
    3070          field <em class="bcp14">MUST</em> either be sent with the value "about:blank", or not be sent at all. Note that this requirement does not apply to sources with
    3071          non-HTTP URIs (e.g., FTP).
    3072       </p>
    3073       <div id="rfc.figure.u.52"></div><pre class="inline"><span id="rfc.iref.g.56"></span>  <a href="#header.referer" class="smpl">Referer</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a>
    3074 </pre><p id="rfc.section.10.15.p.5">Example:</p>
    3075       <div id="rfc.figure.u.53"></div><pre class="text">  Referer: http://www.example.org/hypertext/Overview.html
    3076 </pre><p id="rfc.section.10.15.p.7">If the field value is a relative URI, it <em class="bcp14">SHOULD</em> be interpreted relative to the effective request URI. The URI <em class="bcp14">MUST NOT</em> include a fragment. See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section&nbsp;12.2</a> for security considerations.
    3077       </p>
    3078       <div id="rfc.iref.r.3"></div>
    3079       <div id="rfc.iref.h.17"></div>
    3080       <h2 id="rfc.section.10.16"><a href="#rfc.section.10.16">10.16</a>&nbsp;<a id="header.retry-after" href="#header.retry-after">Retry-After</a></h2>
    3081       <p id="rfc.section.10.16.p.1">The header "Retry-After" field can be used with a <a href="#status.503" class="smpl">503 (Service
    3082             Unavailable)</a> response to indicate how long the service is expected to be unavailable to the requesting client. This field <em class="bcp14">MAY</em> also be used with any <a href="#status.3xx" class="smpl">3xx (Redirection)</a> response to indicate the minimum time the user-agent is asked to wait before issuing the redirected request.
    3083       </p>
    3084       <p id="rfc.section.10.16.p.2">The value of this field can be either an HTTP-date or an integer number of seconds (in decimal) after the time of the response.</p>
    3085       <div id="rfc.figure.u.54"></div><pre class="inline"><span id="rfc.iref.g.57"></span>  <a href="#header.retry-after" class="smpl">Retry-After</a> = <a href="#http.date" class="smpl">HTTP-date</a> / <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>
    3086 </pre><div id="rule.delta-seconds">
    3087          <p id="rfc.section.10.16.p.4">  Time spans are non-negative decimal integers, representing time in seconds.</p>
    3088       </div>
    3089       <div id="rfc.figure.u.55"></div><pre class="inline"><span id="rfc.iref.g.58"></span>  <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>  = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
    3090 </pre><p id="rfc.section.10.16.p.6">Two examples of its use are</p>
    3091       <div id="rfc.figure.u.56"></div><pre class="text">  Retry-After: Fri, 31 Dec 1999 23:59:59 GMT
    3092   Retry-After: 120
    3093 </pre><p id="rfc.section.10.16.p.8">In the latter example, the delay is 2 minutes.</p>
    3094       <div id="rfc.iref.s.44"></div>
    3095       <div id="rfc.iref.h.18"></div>
    3096       <h2 id="rfc.section.10.17"><a href="#rfc.section.10.17">10.17</a>&nbsp;<a id="header.server" href="#header.server">Server</a></h2>
    3097       <p id="rfc.section.10.17.p.1">The "Server" header field contains information about the software used by the origin server to handle the request.</p>
    3098       <p id="rfc.section.10.17.p.2">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section&nbsp;9.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.29"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) identifying the server and any significant subproducts. The product tokens are listed in order of their significance for
    3099          identifying the application.
    3100       </p>
    3101       <div id="rfc.figure.u.57"></div><pre class="inline"><span id="rfc.iref.g.59"></span>  <a href="#header.server" class="smpl">Server</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) )
    3102 </pre><p id="rfc.section.10.17.p.4">Example:</p>
    3103       <div id="rfc.figure.u.58"></div><pre class="text">  Server: CERN/3.0 libwww/2.17
    3104 </pre><p id="rfc.section.10.17.p.6">If the response is being forwarded through a proxy, the proxy application <em class="bcp14">MUST NOT</em> modify the <a href="#header.server" class="smpl">Server</a> header field. Instead, it <em class="bcp14">MUST</em> include a <a href="p1-messaging.html#header.via" class="smpl">Via</a> field (as described in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.30"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>).
    3105       </p>
    3106       <div class="note" id="rfc.section.10.17.p.7">
    3107          <p> <b>Note:</b> Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks
    3108             against software that is known to contain security holes. Server implementers are encouraged to make this field a configurable
    3109             option.
    3110          </p>
    3111       </div>
    3112       <div id="rfc.iref.u.1"></div>
    3113       <div id="rfc.iref.h.19"></div>
    3114       <h2 id="rfc.section.10.18"><a href="#rfc.section.10.18">10.18</a>&nbsp;<a id="header.user-agent" href="#header.user-agent">User-Agent</a></h2>
    3115       <p id="rfc.section.10.18.p.1">The "User-Agent" header field contains information about the user agent originating the request. User agents <em class="bcp14">SHOULD</em> include this field with requests.
    3116       </p>
    3117       <p id="rfc.section.10.18.p.2">Typically, it is used for statistical purposes, the tracing of protocol violations, and tailoring responses to avoid particular
    3118          user agent limitations.
    3119       </p>
    3120       <p id="rfc.section.10.18.p.3">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section&nbsp;9.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.31"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) identifying the agent and its significant subproducts. By convention, the product tokens are listed in order of their significance
    3121          for identifying the application.
    3122       </p>
    3123       <p id="rfc.section.10.18.p.4">Because this field is usually sent on every request a user agent makes, implementations are encouraged not to include needlessly
    3124          fine-grained detail, and to limit (or even prohibit) the addition of subproducts by third parties. Overly long and detailed
    3125          User-Agent field values make requests larger and can also be used to identify ("fingerprint") the user against their wishes.
    3126       </p>
    3127       <p id="rfc.section.10.18.p.5">Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility
    3128          with them, as this circumvents the purpose of the field. Finally, they are encouraged not to use comments to identify products;
    3129          doing so makes the field value more difficult to parse.
    3130       </p>
    3131       <div id="rfc.figure.u.59"></div><pre class="inline"><span id="rfc.iref.g.60"></span>  <a href="#header.user-agent" class="smpl">User-Agent</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) )
    3132 </pre><p id="rfc.section.10.18.p.7">Example:</p>
    3133       <div id="rfc.figure.u.60"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
    3134 </pre><h1 id="rfc.section.11"><a href="#rfc.section.11">11.</a>&nbsp;<a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>
    3135       <h2 id="rfc.section.11.1"><a href="#rfc.section.11.1">11.1</a>&nbsp;<a id="method.registry" href="#method.registry">Method Registry</a></h2>
    3136       <p id="rfc.section.11.1.p.1">The HTTP Method Registry defines the name space for the request method token (<a href="#methods" title="Request Methods">Section&nbsp;5</a>). The method registry is maintained at &lt;<a href="http://www.iana.org/assignments/http-methods">http://www.iana.org/assignments/http-methods</a>&gt;.
    3137       </p>
    3138       <h3 id="rfc.section.11.1.1"><a href="#rfc.section.11.1.1">11.1.1</a>&nbsp;<a id="method.procedure" href="#method.procedure">Procedure</a></h3>
    3139       <p id="rfc.section.11.1.1.p.1">HTTP method registrations <em class="bcp14">MUST</em> include the following fields:
     3142      <h1 id="rfc.section.10"><a href="#rfc.section.10">10.</a>&nbsp;<a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>
     3143      <h2 id="rfc.section.10.1"><a href="#rfc.section.10.1">10.1</a>&nbsp;<a id="method.registry" href="#method.registry">Method Registry</a></h2>
     3144      <p id="rfc.section.10.1.p.1">The HTTP Method Registry defines the name space for the request method token (<a href="#methods" title="Request Methods">Section&nbsp;5</a>). The method registry is maintained at &lt;<a href="http://www.iana.org/assignments/http-methods">http://www.iana.org/assignments/http-methods</a>&gt;.
     3145      </p>
     3146      <h3 id="rfc.section.10.1.1"><a href="#rfc.section.10.1.1">10.1.1</a>&nbsp;<a id="method.procedure" href="#method.procedure">Procedure</a></h3>
     3147      <p id="rfc.section.10.1.1.p.1">HTTP method registrations <em class="bcp14">MUST</em> include the following fields:
    31403148      </p>
    31413149      <ul>
    … …  
    31483156         <li>Pointer to specification text</li>
    31493157      </ul>
    3150       <p id="rfc.section.11.1.1.p.2">Values to be added to this name space require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.1"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>).
    3151       </p>
    3152       <h3 id="rfc.section.11.1.2"><a href="#rfc.section.11.1.2">11.1.2</a>&nbsp;<a id="considerations.for.new.methods" href="#considerations.for.new.methods">Considerations for New Methods</a></h3>
    3153       <p id="rfc.section.11.1.2.p.1">Standardized HTTP methods are generic; that is, they are potentially applicable to any resource, not just one particular media
     3158      <p id="rfc.section.10.1.1.p.2">Values to be added to this name space require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.1"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>).
     3159      </p>
     3160      <h3 id="rfc.section.10.1.2"><a href="#rfc.section.10.1.2">10.1.2</a>&nbsp;<a id="considerations.for.new.methods" href="#considerations.for.new.methods">Considerations for New Methods</a></h3>
     3161      <p id="rfc.section.10.1.2.p.1">Standardized HTTP methods are generic; that is, they are potentially applicable to any resource, not just one particular media
    31543162         type, kind of resource, or application. As such, it is preferred that new HTTP methods be registered in a document that isn't
    31553163         specific to a single application or data format, since orthogonal technologies deserve orthogonal specification.
    31563164      </p>
    3157       <p id="rfc.section.11.1.2.p.2">Since HTTP message parsing (<a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.32"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) is independent of method semantics (aside from responses to HEAD), definitions of new HTTP methods cannot change the parsing
     3165      <p id="rfc.section.10.1.2.p.2">Since HTTP message parsing (<a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.32"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>) is independent of method semantics (aside from responses to HEAD), definitions of new HTTP methods cannot change the parsing
    31583166         algorithm or prohibit the presence of a message body on either the request or the response message. Definitions of new methods
    31593167         can specify that only zero-length bodies are allowed, which would imply that each such messages would be required to contain
    31603168         a Content-Length header field with a value of "0".
    31613169      </p>
    3162       <p id="rfc.section.11.1.2.p.3">New method definitions need to indicate whether they are safe (<a href="#safe.methods" title="Safe Methods">Section&nbsp;5.2.1</a>), idempotent (<a href="#idempotent.methods" title="Idempotent Methods">Section&nbsp;5.2.2</a>), cacheable (<a href="#cacheable.methods" title="Cacheable Methods">Section&nbsp;5.2.3</a>), and what semantics are to be associated with the request body if any is present in the request. If a method is cacheable,
     3170      <p id="rfc.section.10.1.2.p.3">New method definitions need to indicate whether they are safe (<a href="#safe.methods" title="Safe Methods">Section&nbsp;5.2.1</a>), idempotent (<a href="#idempotent.methods" title="Idempotent Methods">Section&nbsp;5.2.2</a>), cacheable (<a href="#cacheable.methods" title="Cacheable Methods">Section&nbsp;5.2.3</a>), and what semantics are to be associated with the request body if any is present in the request. If a method is cacheable,
    31633171         the method definition ought to describe how, and under what conditions, a cache can store a response and use it to satisfy
    31643172         a subsequent request.
    31653173      </p>
    3166       <h3 id="rfc.section.11.1.3"><a href="#rfc.section.11.1.3">11.1.3</a>&nbsp;<a id="method.registration" href="#method.registration">Registrations</a></h3>
    3167       <p id="rfc.section.11.1.3.p.1">The HTTP Method Registry shall be populated with the registrations below:</p>
     3174      <h3 id="rfc.section.10.1.3"><a href="#rfc.section.10.1.3">10.1.3</a>&nbsp;<a id="method.registration" href="#method.registration">Registrations</a></h3>
     3175      <p id="rfc.section.10.1.3.p.1">The HTTP Method Registry shall be populated with the registrations below:</p>
    31683176      <div id="rfc.table.2">
    31693177         <div id="iana.method.registration.table"></div>
    … …  
    32373245         </table>
    32383246      </div>
    3239       <h2 id="rfc.section.11.2"><a href="#rfc.section.11.2">11.2</a>&nbsp;<a id="status.code.registry" href="#status.code.registry">Status Code Registry</a></h2>
    3240       <p id="rfc.section.11.2.p.1">The HTTP Status Code Registry defines the name space for the response status-code token (<a href="#status.codes" title="Response Status Codes">Section&nbsp;7</a>). The status code registry is maintained at &lt;<a href="http://www.iana.org/assignments/http-status-codes">http://www.iana.org/assignments/http-status-codes</a>&gt;.
    3241       </p>
    3242       <p id="rfc.section.11.2.p.2">This section replaces the registration procedure for HTTP Status Codes previously defined in <a href="http://tools.ietf.org/html/rfc2817#section-7.1">Section 7.1</a> of <a href="#RFC2817" id="rfc.xref.RFC2817.1"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>.
    3243       </p>
    3244       <h3 id="rfc.section.11.2.1"><a href="#rfc.section.11.2.1">11.2.1</a>&nbsp;<a id="status.code.procedure" href="#status.code.procedure">Procedure</a></h3>
    3245       <p id="rfc.section.11.2.1.p.1">Values to be added to the HTTP status code name space require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.2"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>).
    3246       </p>
    3247       <h3 id="rfc.section.11.2.2"><a href="#rfc.section.11.2.2">11.2.2</a>&nbsp;<a id="considerations.for.new.status.codes" href="#considerations.for.new.status.codes">Considerations for New Status Codes</a></h3>
    3248       <p id="rfc.section.11.2.2.p.1">When it is necessary to express new semantics for a HTTP response that aren't specific to a single application or media type,
     3247      <h2 id="rfc.section.10.2"><a href="#rfc.section.10.2">10.2</a>&nbsp;<a id="status.code.registry" href="#status.code.registry">Status Code Registry</a></h2>
     3248      <p id="rfc.section.10.2.p.1">The HTTP Status Code Registry defines the name space for the response status-code token (<a href="#status.codes" title="Response Status Codes">Section&nbsp;7</a>). The status code registry is maintained at &lt;<a href="http://www.iana.org/assignments/http-status-codes">http://www.iana.org/assignments/http-status-codes</a>&gt;.
     3249      </p>
     3250      <p id="rfc.section.10.2.p.2">This section replaces the registration procedure for HTTP Status Codes previously defined in <a href="http://tools.ietf.org/html/rfc2817#section-7.1">Section 7.1</a> of <a href="#RFC2817" id="rfc.xref.RFC2817.1"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>.
     3251      </p>
     3252      <h3 id="rfc.section.10.2.1"><a href="#rfc.section.10.2.1">10.2.1</a>&nbsp;<a id="status.code.procedure" href="#status.code.procedure">Procedure</a></h3>
     3253      <p id="rfc.section.10.2.1.p.1">Values to be added to the HTTP status code name space require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.2"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>).
     3254      </p>
     3255      <h3 id="rfc.section.10.2.2"><a href="#rfc.section.10.2.2">10.2.2</a>&nbsp;<a id="considerations.for.new.status.codes" href="#considerations.for.new.status.codes">Considerations for New Status Codes</a></h3>
     3256      <p id="rfc.section.10.2.2.p.1">When it is necessary to express new semantics for a HTTP response that aren't specific to a single application or media type,
    32493257         and currently defined status codes are inadequate, a new status code can be registered.
    32503258      </p>
    3251       <p id="rfc.section.11.2.2.p.2">HTTP status codes are generic; that is, they are potentially applicable to any resource, not just one particular media type,
     3259      <p id="rfc.section.10.2.2.p.2">HTTP status codes are generic; that is, they are potentially applicable to any resource, not just one particular media type,
    32523260         "type" of resource, or application. As such, it is preferred that new HTTP status codes be registered in a document that isn't
    32533261         specific to a single application, so that this is clear.
    32543262      </p>
    3255       <p id="rfc.section.11.2.2.p.3">Definitions of new HTTP status codes typically explain the request conditions that produce a response containing the status
     3263      <p id="rfc.section.10.2.2.p.3">Definitions of new HTTP status codes typically explain the request conditions that produce a response containing the status
    32563264         code (e.g., combinations of request header fields and/or method(s)), along with any interactions with response header fields
    32573265         (e.g., those that are required, those that modify the semantics of the response).
    32583266      </p>
    3259       <p id="rfc.section.11.2.2.p.4">New HTTP status codes are required to fall under one of the categories defined in <a href="#status.codes" title="Response Status Codes">Section&nbsp;7</a>. To allow existing parsers to properly handle them, new status codes cannot disallow a response body, although they can mandate
     3267      <p id="rfc.section.10.2.2.p.4">New HTTP status codes are required to fall under one of the categories defined in <a href="#status.codes" title="Response Status Codes">Section&nbsp;7</a>. To allow existing parsers to properly handle them, new status codes cannot disallow a response body, although they can mandate
    32603268         a zero-length response body. They can require the presence of one or more particular HTTP response header field(s).
    32613269      </p>
    3262       <p id="rfc.section.11.2.2.p.5">Likewise, their definitions can specify that caches are allowed to use heuristics to determine their freshness (see <a href="#Part6" id="rfc.xref.Part6.18"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>; by default, it is not allowed), and can define how to determine the resource which they carry a representation for (see <a href="#identifying.response.associated.with.representation" title="Identifying the Resource Associated with a Representation">Section&nbsp;3.1</a>; by default, it is anonymous).
    3263       </p>
    3264       <h3 id="rfc.section.11.2.3"><a href="#rfc.section.11.2.3">11.2.3</a>&nbsp;<a id="status.code.registration" href="#status.code.registration">Registrations</a></h3>
    3265       <p id="rfc.section.11.2.3.p.1">The HTTP Status Code Registry shall be updated with the registrations below:</p>
     3270      <p id="rfc.section.10.2.2.p.5">Likewise, their definitions can specify that caches are allowed to use heuristics to determine their freshness (see <a href="#Part6" id="rfc.xref.Part6.18"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>; by default, it is not allowed), and can define how to determine the resource which they carry a representation for (see <a href="#identifying.response.associated.with.representation" title="Identifying the Resource Associated with a Representation">Section&nbsp;3.1</a>; by default, it is anonymous).
     3271      </p>
     3272      <h3 id="rfc.section.10.2.3"><a href="#rfc.section.10.2.3">10.2.3</a>&nbsp;<a id="status.code.registration" href="#status.code.registration">Registrations</a></h3>
     3273      <p id="rfc.section.10.2.3.p.1">The HTTP Status Code Registry shall be updated with the registrations below:</p>
    32663274      <div id="rfc.table.3">
    32673275         <div id="iana.status.code.registration.table"></div>
    … …  
    34943502         </table>
    34953503      </div>
    3496       <h2 id="rfc.section.11.3"><a href="#rfc.section.11.3">11.3</a>&nbsp;<a id="header.field.registry" href="#header.field.registry">Header Field Registry</a></h2>
    3497       <p id="rfc.section.11.3.p.1">HTTP header fields are registered within the Message Header Field Registry located at &lt;<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>&gt;, as defined by <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>.
    3498       </p>
    3499       <h3 id="rfc.section.11.3.1"><a href="#rfc.section.11.3.1">11.3.1</a>&nbsp;<a id="considerations.for.new.header.fields" href="#considerations.for.new.header.fields">Considerations for New Header Fields</a></h3>
    3500       <p id="rfc.section.11.3.1.p.1">Header fields are key:value pairs that can be used to communicate data about the message, its payload, the target resource,
     3504      <h2 id="rfc.section.10.3"><a href="#rfc.section.10.3">10.3</a>&nbsp;<a id="header.field.registry" href="#header.field.registry">Header Field Registry</a></h2>
     3505      <p id="rfc.section.10.3.p.1">HTTP header fields are registered within the Message Header Field Registry located at &lt;<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>&gt;, as defined by <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>.
     3506      </p>
     3507      <h3 id="rfc.section.10.3.1"><a href="#rfc.section.10.3.1">10.3.1</a>&nbsp;<a id="considerations.for.new.header.fields" href="#considerations.for.new.header.fields">Considerations for New Header Fields</a></h3>
     3508      <p id="rfc.section.10.3.1.p.1">Header fields are key:value pairs that can be used to communicate data about the message, its payload, the target resource,
    35013509         or the connection (i.e., control data). See <a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.33"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a> for a general definition of header field syntax in HTTP messages.
    35023510      </p>
    3503       <p id="rfc.section.11.3.1.p.2">The requirements for header field names are defined in <a href="http://tools.ietf.org/html/rfc3864#section-4.1">Section 4.1</a> of <a href="#RFC3864" id="rfc.xref.RFC3864.2"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>. Authors of specifications defining new fields are advised to keep the name as short as practical, and not to prefix them
     3511      <p id="rfc.section.10.3.1.p.2">The requirements for header field names are defined in <a href="http://tools.ietf.org/html/rfc3864#section-4.1">Section 4.1</a> of <a href="#RFC3864" id="rfc.xref.RFC3864.2"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>. Authors of specifications defining new fields are advised to keep the name as short as practical, and not to prefix them
    35043512         with "X-" if they are to be registered (either immediately or in the future).
    35053513      </p>
    3506       <p id="rfc.section.11.3.1.p.3">New header field values typically have their syntax defined using ABNF (<a href="#RFC5234" id="rfc.xref.RFC5234.2"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>), using the extension defined in <a href="p1-messaging.html#abnf.extension" title="ABNF list extension: #rule">Appendix B</a> of <a href="#Part1" id="rfc.xref.Part1.34"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a> as necessary, and are usually constrained to the range of ASCII characters. Header fields needing a greater range of characters
     3514      <p id="rfc.section.10.3.1.p.3">New header field values typically have their syntax defined using ABNF (<a href="#RFC5234" id="rfc.xref.RFC5234.2"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>), using the extension defined in <a href="p1-messaging.html#abnf.extension" title="ABNF list extension: #rule">Appendix B</a> of <a href="#Part1" id="rfc.xref.Part1.34"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a> as necessary, and are usually constrained to the range of ASCII characters. Header fields needing a greater range of characters
    35073515         can use an encoding such as the one defined in <a href="#RFC5987" id="rfc.xref.RFC5987.1"><cite title="Character Set and Language Encoding for Hypertext Transfer Protocol (HTTP) Header Field Parameters">[RFC5987]</cite></a>.
    35083516      </p>
    3509       <p id="rfc.section.11.3.1.p.4">Because commas (",") are used as a generic delimiter between field-values, they need to be treated with care if they are allowed
     3517      <p id="rfc.section.10.3.1.p.4">Because commas (",") are used as a generic delimiter between field-values, they need to be treated with care if they are allowed
    35103518         in the field-value's payload. Typically, components that might contain a comma are protected with double-quotes using the
    35113519         quoted-string ABNF production (<a href="p1-messaging.html#field.components" title="Field value components">Section 3.2.4</a> of <a href="#Part1" id="rfc.xref.Part1.35"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>).
    35123520      </p>
    3513       <p id="rfc.section.11.3.1.p.5">For example, a textual date and a URI (either of which might contain a comma) could be safely carried in field-values like
     3521      <p id="rfc.section.10.3.1.p.5">For example, a textual date and a URI (either of which might contain a comma) could be safely carried in field-values like
    35143522         these:
    35153523      </p>
    … …  
    35173525                     "http://without-a-comma.example.com/"
    35183526  Example-Date-Field: "Sat, 04 May 1996", "Wed, 14 Sep 2005"
    3519 </pre><p id="rfc.section.11.3.1.p.7">Note that double-quote delimiters almost always are used with the quoted-string production; using a different syntax inside
     3527</pre><p id="rfc.section.10.3.1.p.7">Note that double-quote delimiters almost always are used with the quoted-string production; using a different syntax inside
    35203528         double-quotes will likely cause unnecessary confusion.
    35213529      </p>
    3522       <p id="rfc.section.11.3.1.p.8">Many header fields use a format including (case-insensitively) named parameters (for instance, <a href="#header.content-type" class="smpl">Content-Type</a>, defined in <a href="#header.content-type" id="rfc.xref.header.content-type.4" title="Content-Type">Section&nbsp;10.9</a>). Allowing both unquoted (token) and quoted (quoted-string) syntax for the parameter value enables recipients to use existing
     3530      <p id="rfc.section.10.3.1.p.8">Many header fields use a format including (case-insensitively) named parameters (for instance, <a href="#header.content-type" class="smpl">Content-Type</a>, defined in <a href="#header.content-type" id="rfc.xref.header.content-type.4" title="Content-Type">Section&nbsp;3.2.1</a>). Allowing both unquoted (token) and quoted (quoted-string) syntax for the parameter value enables recipients to use existing
    35233531         parser components. When allowing both forms, the meaning of a parameter value ought to be independent of the syntax used for
    35243532         it (for an example, see the notes on parameter handling for media types in <a href="#media.types" title="Media Types">Section&nbsp;9.5</a>).
    35253533      </p>
    3526       <p id="rfc.section.11.3.1.p.9">Authors of specifications defining new header fields are advised to consider documenting: </p>
     3534      <p id="rfc.section.10.3.1.p.9">Authors of specifications defining new header fields are advised to consider documenting: </p>
    35273535      <ul>
    35283536         <li>
    … …  
    35613569         </li>
    35623570      </ul>
    3563       <h3 id="rfc.section.11.3.2"><a href="#rfc.section.11.3.2">11.3.2</a>&nbsp;<a id="header.field.registration" href="#header.field.registration">Registrations</a></h3>
    3564       <p id="rfc.section.11.3.2.p.1">The Message Header Field Registry shall be updated with the following permanent registrations:</p>
     3571      <h3 id="rfc.section.10.3.2"><a href="#rfc.section.10.3.2">10.3.2</a>&nbsp;<a id="header.field.registration" href="#header.field.registration">Registrations</a></h3>
     3572      <p id="rfc.section.10.3.2.p.1">The Message Header Field Registry shall be updated with the following permanent registrations:</p>
    35653573      <div id="rfc.table.4">
    35663574         <div id="iana.header.registration.table"></div>
    … …  
    35793587                  <td class="left">http</td>
    35803588                  <td class="left">standard</td>
    3581                   <td class="left"> <a href="#header.accept" id="rfc.xref.header.accept.4" title="Accept">Section&nbsp;10.1</a>
     3589                  <td class="left"> <a href="#header.accept" id="rfc.xref.header.accept.4" title="Accept">Section&nbsp;6.3.2</a>
    35823590                  </td>
    35833591               </tr>
    … …  
    35863594                  <td class="left">http</td>
    35873595                  <td class="left">standard</td>
    3588                   <td class="left"> <a href="#header.accept-charset" id="rfc.xref.header.accept-charset.3" title="Accept-Charset">Section&nbsp;10.2</a>
     3596                  <td class="left"> <a href="#header.accept-charset" id="rfc.xref.header.accept-charset.3" title="Accept-Charset">Section&nbsp;6.3.3</a>
    35893597                  </td>
    35903598               </tr>
    … …  
    35933601                  <td class="left">http</td>
    35943602                  <td class="left">standard</td>
    3595                   <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.4" title="Accept-Encoding">Section&nbsp;10.3</a>
     3603                  <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.4" title="Accept-Encoding">Section&nbsp;6.3.4</a>
    35963604                  </td>
    35973605               </tr>
    … …  
    36003608                  <td class="left">http</td>
    36013609                  <td class="left">standard</td>
    3602                   <td class="left"> <a href="#header.accept-language" id="rfc.xref.header.accept-language.3" title="Accept-Language">Section&nbsp;10.4</a>
     3610                  <td class="left"> <a href="#header.accept-language" id="rfc.xref.header.accept-language.3" title="Accept-Language">Section&nbsp;6.3.5</a>
    36033611                  </td>
    36043612               </tr>
    … …  
    36073615                  <td class="left">http</td>
    36083616                  <td class="left">standard</td>
    3609                   <td class="left"> <a href="#header.allow" id="rfc.xref.header.allow.3" title="Allow">Section&nbsp;10.5</a>
     3617                  <td class="left"> <a href="#header.allow" id="rfc.xref.header.allow.3" title="Allow">Section&nbsp;8.4.1</a>
    36103618                  </td>
    36113619               </tr>
    … …  
    36143622                  <td class="left">http</td>
    36153623                  <td class="left">standard</td>
    3616                   <td class="left"> <a href="#header.content-encoding" id="rfc.xref.header.content-encoding.3" title="Content-Encoding">Section&nbsp;10.6</a>
     3624                  <td class="left"> <a href="#header.content-encoding" id="rfc.xref.header.content-encoding.3" title="Content-Encoding">Section&nbsp;3.2.2</a>
    36173625                  </td>
    36183626               </tr>
    … …  
    36213629                  <td class="left">http</td>
    36223630                  <td class="left">standard</td>
    3623                   <td class="left"> <a href="#header.content-language" id="rfc.xref.header.content-language.2" title="Content-Language">Section&nbsp;10.7</a>
     3631                  <td class="left"> <a href="#header.content-language" id="rfc.xref.header.content-language.2" title="Content-Language">Section&nbsp;3.2.3</a>
    36243632                  </td>
    36253633               </tr>
    … …  
    36283636                  <td class="left">http</td>
    36293637                  <td class="left">standard</td>
    3630                   <td class="left"> <a href="#header.content-location" id="rfc.xref.header.content-location.4" title="Content-Location">Section&nbsp;10.8</a>
     3638                  <td class="left"> <a href="#header.content-location" id="rfc.xref.header.content-location.4" title="Content-Location">Section&nbsp;3.2.4</a>
    36313639                  </td>
    36323640               </tr>
    … …  
    36353643                  <td class="left">http</td>
    36363644                  <td class="left">standard</td>
    3637                   <td class="left"> <a href="#header.content-type" id="rfc.xref.header.content-type.5" title="Content-Type">Section&nbsp;10.9</a>
     3645                  <td class="left"> <a href="#header.content-type" id="rfc.xref.header.content-type.5" title="Content-Type">Section&nbsp;3.2.1</a>
    36383646                  </td>
    36393647               </tr>
    … …  
    36423650                  <td class="left">http</td>
    36433651                  <td class="left">standard</td>
    3644                   <td class="left"> <a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section&nbsp;10.10</a>
     3652                  <td class="left"> <a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section&nbsp;8.2.1</a>
    36453653                  </td>
    36463654               </tr>
    … …  
    36493657                  <td class="left">http</td>
    36503658                  <td class="left">standard</td>
    3651                   <td class="left"> <a href="#header.expect" id="rfc.xref.header.expect.3" title="Expect">Section&nbsp;10.11</a>
     3659                  <td class="left"> <a href="#header.expect" id="rfc.xref.header.expect.3" title="Expect">Section&nbsp;6.1.2</a>
    36523660                  </td>
    36533661               </tr>
    … …  
    36563664                  <td class="left">http</td>
    36573665                  <td class="left">standard</td>
    3658                   <td class="left"> <a href="#header.from" id="rfc.xref.header.from.2" title="From">Section&nbsp;10.12</a>
     3666                  <td class="left"> <a href="#header.from" id="rfc.xref.header.from.2" title="From">Section&nbsp;6.5.1</a>
    36593667                  </td>
    36603668               </tr>
    … …  
    36633671                  <td class="left">http</td>
    36643672                  <td class="left">standard</td>
    3665                   <td class="left"> <a href="#header.location" id="rfc.xref.header.location.4" title="Location">Section&nbsp;10.13</a>
     3673                  <td class="left"> <a href="#header.location" id="rfc.xref.header.location.4" title="Location">Section&nbsp;8.1.1</a>
    36663674                  </td>
    36673675               </tr>
    … …  
    36773685                  <td class="left">http</td>
    36783686                  <td class="left">standard</td>
    3679                   <td class="left"> <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.4" title="Max-Forwards">Section&nbsp;10.14</a>
     3687                  <td class="left"> <a href="#header.max-forwards" id="rfc.xref.header.max-forwards.4" title="Max-Forwards">Section&nbsp;6.1.1</a>
    36803688                  </td>
    36813689               </tr>
    … …  
    36843692                  <td class="left">http</td>
    36853693                  <td class="left">standard</td>
    3686                   <td class="left"> <a href="#header.referer" id="rfc.xref.header.referer.2" title="Referer">Section&nbsp;10.15</a>
     3694                  <td class="left"> <a href="#header.referer" id="rfc.xref.header.referer.2" title="Referer">Section&nbsp;6.5.2</a>
    36873695                  </td>
    36883696               </tr>
    … …  
    36913699                  <td class="left">http</td>
    36923700                  <td class="left">standard</td>
    3693                   <td class="left"> <a href="#header.retry-after" id="rfc.xref.header.retry-after.3" title="Retry-After">Section&nbsp;10.16</a>
     3701                  <td class="left"> <a href="#header.retry-after" id="rfc.xref.header.retry-after.3" title="Retry-After">Section&nbsp;8.1.2</a>
    36943702                  </td>
    36953703               </tr>
    … …  
    36983706                  <td class="left">http</td>
    36993707                  <td class="left">standard</td>
    3700                   <td class="left"> <a href="#header.server" id="rfc.xref.header.server.2" title="Server">Section&nbsp;10.17</a>
     3708                  <td class="left"> <a href="#header.server" id="rfc.xref.header.server.2" title="Server">Section&nbsp;8.4.2</a>
    37013709                  </td>
    37023710               </tr>
    … …  
    37053713                  <td class="left">http</td>
    37063714                  <td class="left">standard</td>
    3707                   <td class="left"> <a href="#header.user-agent" id="rfc.xref.header.user-agent.3" title="User-Agent">Section&nbsp;10.18</a>
     3715                  <td class="left"> <a href="#header.user-agent" id="rfc.xref.header.user-agent.3" title="User-Agent">Section&nbsp;6.5.3</a>
    37083716                  </td>
    37093717               </tr>
    … …  
    37113719         </table>
    37123720      </div>
    3713       <p id="rfc.section.11.3.2.p.2">The change controller for the above registrations is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
    3714       <h2 id="rfc.section.11.4"><a href="#rfc.section.11.4">11.4</a>&nbsp;<a id="content.coding.registry" href="#content.coding.registry">Content Coding Registry</a></h2>
    3715       <p id="rfc.section.11.4.p.1">The HTTP Content Coding Registry defines the name space for content coding names (<a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 4.2</a> of <a href="#Part1" id="rfc.xref.Part1.39"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>). The content coding registry is maintained at &lt;<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>&gt;.
    3716       </p>
    3717       <h3 id="rfc.section.11.4.1"><a href="#rfc.section.11.4.1">11.4.1</a>&nbsp;<a id="content.coding.procedure" href="#content.coding.procedure">Procedure</a></h3>
    3718       <p id="rfc.section.11.4.1.p.1">Content Coding registrations <em class="bcp14">MUST</em> include the following fields:
     3721      <p id="rfc.section.10.3.2.p.2">The change controller for the above registrations is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
     3722      <h2 id="rfc.section.10.4"><a href="#rfc.section.10.4">10.4</a>&nbsp;<a id="content.coding.registry" href="#content.coding.registry">Content Coding Registry</a></h2>
     3723      <p id="rfc.section.10.4.p.1">The HTTP Content Coding Registry defines the name space for content coding names (<a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 4.2</a> of <a href="#Part1" id="rfc.xref.Part1.39"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>). The content coding registry is maintained at &lt;<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>&gt;.
     3724      </p>
     3725      <h3 id="rfc.section.10.4.1"><a href="#rfc.section.10.4.1">10.4.1</a>&nbsp;<a id="content.coding.procedure" href="#content.coding.procedure">Procedure</a></h3>
     3726      <p id="rfc.section.10.4.1.p.1">Content Coding registrations <em class="bcp14">MUST</em> include the following fields:
    37193727      </p>
    37203728      <ul>
    … …  
    37233731         <li>Pointer to specification text</li>
    37243732      </ul>
    3725       <p id="rfc.section.11.4.1.p.2">Names of content codings <em class="bcp14">MUST NOT</em> overlap with names of transfer codings (<a href="p1-messaging.html#transfer.codings" title="Transfer Codings">Section 4</a> of <a href="#Part1" id="rfc.xref.Part1.40"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>), unless the encoding transformation is identical (as is the case for the compression codings defined in <a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 4.2</a> of <a href="#Part1" id="rfc.xref.Part1.41"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>).
    3726       </p>
    3727       <p id="rfc.section.11.4.1.p.3">Values to be added to this name space require IETF Review (see <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a> of <a href="#RFC5226" id="rfc.xref.RFC5226.3"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>), and <em class="bcp14">MUST</em> conform to the purpose of content coding defined in this section.
    3728       </p>
    3729       <h3 id="rfc.section.11.4.2"><a href="#rfc.section.11.4.2">11.4.2</a>&nbsp;<a id="content.coding.registration" href="#content.coding.registration">Registrations</a></h3>
    3730       <p id="rfc.section.11.4.2.p.1">The HTTP Content Codings Registry shall be updated with the registrations below:</p>
     3733      <p id="rfc.section.10.4.1.p.2">Names of content codings <em class="bcp14">MUST NOT</em> overlap with names of transfer codings (<a href="p1-messaging.html#transfer.codings" title="Transfer Codings">Section 4</a> of <a href="#Part1" id="rfc.xref.Part1.40"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>), unless the encoding transformation is identical (as is the case for the compression codings defined in <a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 4.2</a> of <a href="#Part1" id="rfc.xref.Part1.41"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>).
     3734      </p>
     3735      <p id="rfc.section.10.4.1.p.3">Values to be added to this name space require IETF Review (see <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a> of <a href="#RFC5226" id="rfc.xref.RFC5226.3"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>), and <em class="bcp14">MUST</em> conform to the purpose of content coding defined in this section.
     3736      </p>
     3737      <h3 id="rfc.section.10.4.2"><a href="#rfc.section.10.4.2">10.4.2</a>&nbsp;<a id="content.coding.registration" href="#content.coding.registration">Registrations</a></h3>
     3738      <p id="rfc.section.10.4.2.p.1">The HTTP Content Codings Registry shall be updated with the registrations below:</p>
    37313739      <div id="rfc.table.5">
    37323740         <div id="iana.content.coding.registration.table"></div>
    … …  
    37633771                  <td class="left">reserved (synonym for "no encoding" in <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> header field)
    37643772                  </td>
    3765                   <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.5" title="Accept-Encoding">Section&nbsp;10.3</a>
     3773                  <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.5" title="Accept-Encoding">Section&nbsp;6.3.4</a>
    37663774                  </td>
    37673775               </tr>
    … …  
    37693777         </table>
    37703778      </div>
    3771       <h1 id="rfc.section.12"><a href="#rfc.section.12">12.</a>&nbsp;<a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>
    3772       <p id="rfc.section.12.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1
     3779      <h1 id="rfc.section.11"><a href="#rfc.section.11">11.</a>&nbsp;<a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>
     3780      <p id="rfc.section.11.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1
    37733781         as described by this document. The discussion does not include definitive solutions to the problems revealed, though it does
    37743782         make some suggestions for reducing security risks.
    37753783      </p>
    3776       <h2 id="rfc.section.12.1"><a href="#rfc.section.12.1">12.1</a>&nbsp;<a id="security.sensitive" href="#security.sensitive">Transfer of Sensitive Information</a></h2>
    3777       <p id="rfc.section.12.1.p.1">Like any generic data transfer protocol, HTTP cannot regulate the content of the data that is transferred, nor is there any
     3784      <h2 id="rfc.section.11.1"><a href="#rfc.section.11.1">11.1</a>&nbsp;<a id="security.sensitive" href="#security.sensitive">Transfer of Sensitive Information</a></h2>
     3785      <p id="rfc.section.11.1.p.1">Like any generic data transfer protocol, HTTP cannot regulate the content of the data that is transferred, nor is there any
    37783786         a priori method of determining the sensitivity of any particular piece of information within the context of any given request.
    37793787         Therefore, applications <em class="bcp14">SHOULD</em> supply as much control over this information as possible to the provider of that information. Four header fields are worth
    37803788         special mention in this context: <a href="#header.server" class="smpl">Server</a>, <a href="p1-messaging.html#header.via" class="smpl">Via</a>, <a href="#header.referer" class="smpl">Referer</a> and <a href="#header.from" class="smpl">From</a>.
    37813789      </p>
    3782       <p id="rfc.section.12.1.p.2">Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks
     3790      <p id="rfc.section.11.1.p.2">Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks
    37833791         against software that is known to contain security holes. Implementers <em class="bcp14">SHOULD</em> make the <a href="#header.server" class="smpl">Server</a> header field a configurable option.
    37843792      </p>
    3785       <p id="rfc.section.12.1.p.3">Proxies which serve as a portal through a network firewall <em class="bcp14">SHOULD</em> take special precautions regarding the transfer of header information that identifies the hosts behind the firewall. In particular,
     3793      <p id="rfc.section.11.1.p.3">Proxies which serve as a portal through a network firewall <em class="bcp14">SHOULD</em> take special precautions regarding the transfer of header information that identifies the hosts behind the firewall. In particular,
    37863794         they <em class="bcp14">SHOULD</em> remove, or replace with sanitized versions, any <a href="p1-messaging.html#header.via" class="smpl">Via</a> fields generated behind the firewall.
    37873795      </p>
    3788       <p id="rfc.section.12.1.p.4">The <a href="#header.referer" class="smpl">Referer</a> header field allows reading patterns to be studied and reverse links drawn. Although it can be very useful, its power can
     3796      <p id="rfc.section.11.1.p.4">The <a href="#header.referer" class="smpl">Referer</a> header field allows reading patterns to be studied and reverse links drawn. Although it can be very useful, its power can
    37893797         be abused if user details are not separated from the information contained in the Referer. Even when the personal information
    37903798         has been removed, the Referer header field might indicate a private document's URI whose publication would be inappropriate.
    37913799      </p>
    3792       <p id="rfc.section.12.1.p.5">The information sent in the <a href="#header.from" class="smpl">From</a> field might conflict with the user's privacy interests or their site's security policy, and hence it <em class="bcp14">SHOULD NOT</em> be transmitted without the user being able to disable, enable, and modify the contents of the field. The user <em class="bcp14">MUST</em> be able to set the contents of this field within a user preference or application defaults configuration.
    3793       </p>
    3794       <p id="rfc.section.12.1.p.6">We suggest, though do not require, that a convenient toggle interface be provided for the user to enable or disable the sending
     3800      <p id="rfc.section.11.1.p.5">The information sent in the <a href="#header.from" class="smpl">From</a> field might conflict with the user's privacy interests or their site's security policy, and hence it <em class="bcp14">SHOULD NOT</em> be transmitted without the user being able to disable, enable, and modify the contents of the field. The user <em class="bcp14">MUST</em> be able to set the contents of this field within a user preference or application defaults configuration.
     3801      </p>
     3802      <p id="rfc.section.11.1.p.6">We suggest, though do not require, that a convenient toggle interface be provided for the user to enable or disable the sending
    37953803         of <a href="#header.from" class="smpl">From</a> and <a href="#header.referer" class="smpl">Referer</a> information.
    37963804      </p>
    3797       <p id="rfc.section.12.1.p.7">The <a href="#header.user-agent" class="smpl">User-Agent</a> (<a href="#header.user-agent" id="rfc.xref.header.user-agent.4" title="User-Agent">Section&nbsp;10.18</a>) or <a href="#header.server" class="smpl">Server</a> (<a href="#header.server" id="rfc.xref.header.server.3" title="Server">Section&nbsp;10.17</a>) header fields can sometimes be used to determine that a specific client or server has a particular security hole which might
     3805      <p id="rfc.section.11.1.p.7">The <a href="#header.user-agent" class="smpl">User-Agent</a> (<a href="#header.user-agent" id="rfc.xref.header.user-agent.4" title="User-Agent">Section&nbsp;6.5.3</a>) or <a href="#header.server" class="smpl">Server</a> (<a href="#header.server" id="rfc.xref.header.server.3" title="Server">Section&nbsp;8.4.2</a>) header fields can sometimes be used to determine that a specific client or server has a particular security hole which might
    37983806         be exploited. Unfortunately, this same information is often used for other valuable purposes for which HTTP currently has
    37993807         no better mechanism.
    38003808      </p>
    3801       <p id="rfc.section.12.1.p.8">Furthermore, the <a href="#header.user-agent" class="smpl">User-Agent</a> header field might contain enough entropy to be used, possibly in conjunction with other material, to uniquely identify the
     3809      <p id="rfc.section.11.1.p.8">Furthermore, the <a href="#header.user-agent" class="smpl">User-Agent</a> header field might contain enough entropy to be used, possibly in conjunction with other material, to uniquely identify the
    38023810         user.
    38033811      </p>
    3804       <p id="rfc.section.12.1.p.9">Some request methods, like TRACE (<a href="#TRACE" id="rfc.xref.TRACE.4" title="TRACE">Section&nbsp;5.3.8</a>), expose information that was sent in request header fields within the body of their response. Clients <em class="bcp14">SHOULD</em> be careful with sensitive information, like Cookies, Authorization credentials, and other header fields that might be used
     3812      <p id="rfc.section.11.1.p.9">Some request methods, like TRACE (<a href="#TRACE" id="rfc.xref.TRACE.4" title="TRACE">Section&nbsp;5.3.8</a>), expose information that was sent in request header fields within the body of their response. Clients <em class="bcp14">SHOULD</em> be careful with sensitive information, like Cookies, Authorization credentials, and other header fields that might be used
    38053813         to collect data from the client.
    38063814      </p>
    3807       <h2 id="rfc.section.12.2"><a href="#rfc.section.12.2">12.2</a>&nbsp;<a id="encoding.sensitive.information.in.uris" href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></h2>
    3808       <p id="rfc.section.12.2.p.1">Because the source of a link might be private information or might reveal an otherwise private information source, it is strongly
     3815      <h2 id="rfc.section.11.2"><a href="#rfc.section.11.2">11.2</a>&nbsp;<a id="encoding.sensitive.information.in.uris" href="#encoding.sensitive.information.in.uris">Encoding Sensitive Information in URIs</a></h2>
     3816      <p id="rfc.section.11.2.p.1">Because the source of a link might be private information or might reveal an otherwise private information source, it is strongly
    38093817         recommended that the user be able to select whether or not the <a href="#header.referer" class="smpl">Referer</a> field is sent. For example, a browser client could have a toggle switch for browsing openly/anonymously, which would respectively
    38103818         enable/disable the sending of Referer and From information.
    38113819      </p>
    3812       <p id="rfc.section.12.2.p.2">Clients <em class="bcp14">SHOULD NOT</em> include a <a href="#header.referer" class="smpl">Referer</a> header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol.
    3813       </p>
    3814       <p id="rfc.section.12.2.p.3">Authors of services <em class="bcp14">SHOULD NOT</em> use GET-based forms for the submission of sensitive data because that data will be placed in the request-target. Many existing
     3820      <p id="rfc.section.11.2.p.2">Clients <em class="bcp14">SHOULD NOT</em> include a <a href="#header.referer" class="smpl">Referer</a> header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol.
     3821      </p>
     3822      <p id="rfc.section.11.2.p.3">Authors of services <em class="bcp14">SHOULD NOT</em> use GET-based forms for the submission of sensitive data because that data will be placed in the request-target. Many existing
    38153823         servers, proxies, and user agents log or display the request-target in places where it might be visible to third parties.
    38163824         Such services can use POST-based form submission instead.
    38173825      </p>
    3818       <h2 id="rfc.section.12.3"><a href="#rfc.section.12.3">12.3</a>&nbsp;<a id="location.spoofing-leakage" href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></h2>
    3819       <p id="rfc.section.12.3.p.1">If a single server supports multiple organizations that do not trust one another, then it <em class="bcp14">MUST</em> check the values of <a href="#header.location" class="smpl">Location</a> and <a href="#header.content-location" class="smpl">Content-Location</a> header fields in responses that are generated under control of said organizations to make sure that they do not attempt to
     3826      <h2 id="rfc.section.11.3"><a href="#rfc.section.11.3">11.3</a>&nbsp;<a id="location.spoofing-leakage" href="#location.spoofing-leakage">Location Header Fields: Spoofing and Information Leakage</a></h2>
     3827      <p id="rfc.section.11.3.p.1">If a single server supports multiple organizations that do not trust one another, then it <em class="bcp14">MUST</em> check the values of <a href="#header.location" class="smpl">Location</a> and <a href="#header.content-location" class="smpl">Content-Location</a> header fields in responses that are generated under control of said organizations to make sure that they do not attempt to
    38203828         invalidate resources over which they have no authority.
    38213829      </p>
    3822       <p id="rfc.section.12.3.p.2">Furthermore, appending the fragment identifier from one URI to another one obtained from a <a href="#header.location" class="smpl">Location</a> header field might leak confidential information to the target server — although the fragment identifier is not transmitted
     3830      <p id="rfc.section.11.3.p.2">Furthermore, appending the fragment identifier from one URI to another one obtained from a <a href="#header.location" class="smpl">Location</a> header field might leak confidential information to the target server — although the fragment identifier is not transmitted
    38233831         in the final request, it might be visible to the user agent through other means, such as scripting.
    38243832      </p>
    3825       <h2 id="rfc.section.12.4"><a href="#rfc.section.12.4">12.4</a>&nbsp;Security Considerations for CONNECT
     3833      <h2 id="rfc.section.11.4"><a href="#rfc.section.11.4">11.4</a>&nbsp;Security Considerations for CONNECT
    38263834      </h2>
    3827       <p id="rfc.section.12.4.p.1">Since tunneled data is opaque to the proxy, there are additional risks to tunneling to other well-known or reserved ports.
     3835      <p id="rfc.section.11.4.p.1">Since tunneled data is opaque to the proxy, there are additional risks to tunneling to other well-known or reserved ports.
    38283836         A HTTP client CONNECTing to port 25 could relay spam via SMTP, for example. As such, proxies <em class="bcp14">SHOULD</em> restrict CONNECT access to a small number of known ports.
    38293837      </p>
    3830       <h2 id="rfc.section.12.5"><a href="#rfc.section.12.5">12.5</a>&nbsp;<a id="privacy.issues.connected.to.accept.header.fields" href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></h2>
    3831       <p id="rfc.section.12.5.p.1">Accept header fields can reveal information about the user to all servers which are accessed. The <a href="#header.accept-language" class="smpl">Accept-Language</a> header field in particular can reveal information the user would consider to be of a private nature, because the understanding
     3838      <h2 id="rfc.section.11.5"><a href="#rfc.section.11.5">11.5</a>&nbsp;<a id="privacy.issues.connected.to.accept.header.fields" href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></h2>
     3839      <p id="rfc.section.11.5.p.1">Accept header fields can reveal information about the user to all servers which are accessed. The <a href="#header.accept-language" class="smpl">Accept-Language</a> header field in particular can reveal information the user would consider to be of a private nature, because the understanding
    38323840         of particular languages is often strongly correlated to the membership of a particular ethnic group. User agents which offer
    38333841         the option to configure the contents of an Accept-Language header field to be sent in every request are strongly encouraged
    38343842         to let the configuration process include a message which makes the user aware of the loss of privacy involved.
    38353843      </p>
    3836       <p id="rfc.section.12.5.p.2">An approach that limits the loss of privacy would be for a user agent to omit the sending of Accept-Language header fields
     3844      <p id="rfc.section.11.5.p.2">An approach that limits the loss of privacy would be for a user agent to omit the sending of Accept-Language header fields
    38373845         by default, and to ask the user whether or not to start sending Accept-Language header fields to a server if it detects, by
    38383846         looking for any <a href="p6-cache.html#header.vary" class="smpl">Vary</a> header fields generated by the server, that such sending could improve the quality of service.
    38393847      </p>
    3840       <p id="rfc.section.12.5.p.3">Elaborate user-customized accept header fields sent in every request, in particular if these include quality values, can be
     3848      <p id="rfc.section.11.5.p.3">Elaborate user-customized accept header fields sent in every request, in particular if these include quality values, can be
    38413849         used by servers as relatively reliable and long-lived user identifiers. Such user identifiers would allow content providers
    38423850         to do click-trail tracking, and would allow collaborating content providers to match cross-server click-trails or form submissions
    … …  
    38473855         field configurability <em class="bcp14">SHOULD</em> warn users about the loss of privacy which can be involved.
    38483856      </p>
    3849       <h1 id="rfc.section.13"><a href="#rfc.section.13">13.</a>&nbsp;<a id="acks" href="#acks">Acknowledgments</a></h1>
    3850       <p id="rfc.section.13.p.1">See <a href="p1-messaging.html#acks" title="Acknowledgments">Section 9</a> of <a href="#Part1" id="rfc.xref.Part1.45"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
    3851       </p>
    3852       <h1 id="rfc.references"><a id="rfc.section.14" href="#rfc.section.14">14.</a> References
     3857      <h1 id="rfc.section.12"><a href="#rfc.section.12">12.</a>&nbsp;<a id="acks" href="#acks">Acknowledgments</a></h1>
     3858      <p id="rfc.section.12.p.1">See <a href="p1-messaging.html#acks" title="Acknowledgments">Section 9</a> of <a href="#Part1" id="rfc.xref.Part1.45"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>.
     3859      </p>
     3860      <h1 id="rfc.references"><a id="rfc.section.13" href="#rfc.section.13">13.</a> References
    38533861      </h1>
    3854       <h2 id="rfc.references.1"><a href="#rfc.section.14.1" id="rfc.section.14.1">14.1</a> Normative References
     3862      <h2 id="rfc.references.1"><a href="#rfc.section.13.1" id="rfc.section.13.1">13.1</a> Normative References
    38553863      </h2>
    38563864      <table>                             
    … …  
    39313939         </tr>
    39323940      </table>
    3933       <h2 id="rfc.references.2"><a href="#rfc.section.14.2" id="rfc.section.14.2">14.2</a> Informative References
     3941      <h2 id="rfc.references.2"><a href="#rfc.section.13.2" id="rfc.section.13.2">13.2</a> Informative References
    39343942      </h2>
    39353943      <table>                                           
    … …  
    41224130      </p>
    41234131      <h1 id="rfc.section.C"><a href="#rfc.section.C">C.</a>&nbsp;<a id="changes.from.rfc.2616" href="#changes.from.rfc.2616">Changes from RFC 2616</a></h1>
    4124       <p id="rfc.section.C.p.1">Introduce Method Registry. (<a href="#method.registry" title="Method Registry">Section&nbsp;11.1</a>)
     4132      <p id="rfc.section.C.p.1">Introduce Method Registry. (<a href="#method.registry" title="Method Registry">Section&nbsp;10.1</a>)
    41254133      </p>
    41264134      <p id="rfc.section.C.p.2">Clarify definition of POST. (<a href="#POST" id="rfc.xref.POST.3" title="POST">Section&nbsp;5.3.3</a>)
    … …  
    41304138      <p id="rfc.section.C.p.4">Take over definition of CONNECT method from <a href="#RFC2817" id="rfc.xref.RFC2817.2"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>. (<a href="#CONNECT" id="rfc.xref.CONNECT.3" title="CONNECT">Section&nbsp;5.3.6</a>)
    41314139      </p>
    4132       <p id="rfc.section.C.p.5">Take over the Status Code Registry, previously defined in <a href="http://tools.ietf.org/html/rfc2817#section-7.1">Section 7.1</a> of <a href="#RFC2817" id="rfc.xref.RFC2817.3"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>. (<a href="#status.code.registry" title="Status Code Registry">Section&nbsp;11.2</a>)
     4140      <p id="rfc.section.C.p.5">Take over the Status Code Registry, previously defined in <a href="http://tools.ietf.org/html/rfc2817#section-7.1">Section 7.1</a> of <a href="#RFC2817" id="rfc.xref.RFC2817.3"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>. (<a href="#status.code.registry" title="Status Code Registry">Section&nbsp;10.2</a>)
    41334141      </p>
    41344142      <p id="rfc.section.C.p.6">Broadened the definition of <a href="#status.203" class="smpl">203 (Non-Authoritative Information)</a> to include cases of payload transformations as well. (<a href="#status.203" id="rfc.xref.status.203.3" title="203 Non-Authoritative Information">Section&nbsp;7.3.4</a>)
    … …  
    41464154      <p id="rfc.section.C.p.10">Define status <a href="#status.426" class="smpl">426 (Upgrade Required)</a> (this was incorporated from <a href="#RFC2817" id="rfc.xref.RFC2817.4"><cite title="Upgrading to TLS Within HTTP/1.1">[RFC2817]</cite></a>). (<a href="#status.426" id="rfc.xref.status.426.3" title="426 Upgrade Required">Section&nbsp;7.5.15</a>)
    41474155      </p>
    4148       <p id="rfc.section.C.p.11">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section&nbsp;10</a>)
    4149       </p>
     4156      <p id="rfc.section.C.p.11">Change ABNF productions for header fields to only define the field value.</p>
    41504157      <p id="rfc.section.C.p.12">Reclassify "<a href="#header.allow" class="smpl">Allow</a>" as response header field, removing the option to specify it in a PUT request. Relax the server requirement on the contents
    4151          of the Allow header field and remove requirement on clients to always trust the header field value. (<a href="#header.allow" id="rfc.xref.header.allow.4" title="Allow">Section&nbsp;10.5</a>)
     4158         of the Allow header field and remove requirement on clients to always trust the header field value. (<a href="#header.allow" id="rfc.xref.header.allow.4" title="Allow">Section&nbsp;8.4.1</a>)
    41524159      </p>
    41534160      <p id="rfc.section.C.p.13">The ABNF for the <a href="#header.expect" class="smpl">Expect</a> header field has been both fixed (allowing parameters for value-less expectations as well) and simplified (allowing trailing
    4154          semicolons after "100-continue" when they were invalid before). (<a href="#header.expect" id="rfc.xref.header.expect.4" title="Expect">Section&nbsp;10.11</a>)
     4161         semicolons after "100-continue" when they were invalid before). (<a href="#header.expect" id="rfc.xref.header.expect.4" title="Expect">Section&nbsp;6.1.2</a>)
    41554162      </p>
    41564163      <p id="rfc.section.C.p.14">Correct syntax of <a href="#header.location" class="smpl">Location</a> header field to allow URI references (including relative references and fragments), as referred symbol "absoluteURI" wasn't
    4157          what was expected, and add some clarifications as to when use of fragments would not be appropriate. (<a href="#header.location" id="rfc.xref.header.location.5" title="Location">Section&nbsp;10.13</a>)
    4158       </p>
    4159       <p id="rfc.section.C.p.15">Restrict <a href="#header.max-forwards" class="smpl">Max-Forwards</a> header field to OPTIONS and TRACE (previously, extension methods could have used it as well). (<a href="#header.max-forwards" id="rfc.xref.header.max-forwards.5" title="Max-Forwards">Section&nbsp;10.14</a>)
    4160       </p>
    4161       <p id="rfc.section.C.p.16">Allow <a href="#header.referer" class="smpl">Referer</a> field value of "about:blank" as alternative to not specifying it. (<a href="#header.referer" id="rfc.xref.header.referer.3" title="Referer">Section&nbsp;10.15</a>)
    4162       </p>
    4163       <p id="rfc.section.C.p.17">In the description of the <a href="#header.server" class="smpl">Server</a> header field, the <a href="p1-messaging.html#header.via" class="smpl">Via</a> field was described as a SHOULD. The requirement was and is stated correctly in the description of the Via header field in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.46"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>. (<a href="#header.server" id="rfc.xref.header.server.4" title="Server">Section&nbsp;10.17</a>)
     4164         what was expected, and add some clarifications as to when use of fragments would not be appropriate. (<a href="#header.location" id="rfc.xref.header.location.5" title="Location">Section&nbsp;8.1.1</a>)
     4165      </p>
     4166      <p id="rfc.section.C.p.15">Restrict <a href="#header.max-forwards" class="smpl">Max-Forwards</a> header field to OPTIONS and TRACE (previously, extension methods could have used it as well). (<a href="#header.max-forwards" id="rfc.xref.header.max-forwards.5" title="Max-Forwards">Section&nbsp;6.1.1</a>)
     4167      </p>
     4168      <p id="rfc.section.C.p.16">Allow <a href="#header.referer" class="smpl">Referer</a> field value of "about:blank" as alternative to not specifying it. (<a href="#header.referer" id="rfc.xref.header.referer.3" title="Referer">Section&nbsp;6.5.2</a>)
     4169      </p>
     4170      <p id="rfc.section.C.p.17">In the description of the <a href="#header.server" class="smpl">Server</a> header field, the <a href="p1-messaging.html#header.via" class="smpl">Via</a> field was described as a SHOULD. The requirement was and is stated correctly in the description of the Via header field in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.46"><cite title="HTTP/1.1, part 1: Message Routing and Syntax&#34;">[Part1]</cite></a>. (<a href="#header.server" id="rfc.xref.header.server.4" title="Server">Section&nbsp;8.4.2</a>)
    41644171      </p>
    41654172      <p id="rfc.section.C.p.18">Clarify contexts that charset is used in. (<a href="#character.sets" title="Character Encodings (charset)">Section&nbsp;9.3</a>)
    41664173      </p>
    4167       <p id="rfc.section.C.p.19">Registration of Content Codings now requires IETF Review (<a href="#content.coding.registry" title="Content Coding Registry">Section&nbsp;11.4</a>)
     4174      <p id="rfc.section.C.p.19">Registration of Content Codings now requires IETF Review (<a href="#content.coding.registry" title="Content Coding Registry">Section&nbsp;10.4</a>)
    41684175      </p>
    41694176      <p id="rfc.section.C.p.20">Remove the default character encoding of "ISO-8859-1" for text media types; the default now is whatever the media type definition
    41704177         says. (<a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section&nbsp;9.5.1</a>)
    41714178      </p>
    4172       <p id="rfc.section.C.p.21">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section&nbsp;10</a>)
    4173       </p>
     4179      <p id="rfc.section.C.p.21">Change ABNF productions for header fields to only define the field value.</p>
    41744180      <p id="rfc.section.C.p.22">Remove definition of Content-MD5 header field because it was inconsistently implemented with respect to partial responses,
    4175          and also because of known deficiencies in the hash algorithm itself (see <a href="#RFC6151" id="rfc.xref.RFC6151.1"><cite title="Updated Security Considerations for the MD5 Message-Digest and the HMAC-MD5 Algorithms">[RFC6151]</cite></a> for details). (<a href="#header.field.definitions" title="Header Field Definitions">Section&nbsp;10</a>)
    4176       </p>
    4177       <p id="rfc.section.C.p.23">Remove ISO-8859-1 special-casing in <a href="#header.accept-charset" class="smpl">Accept-Charset</a>. (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.4" title="Accept-Charset">Section&nbsp;10.2</a>)
     4181         and also because of known deficiencies in the hash algorithm itself (see <a href="#RFC6151" id="rfc.xref.RFC6151.1"><cite title="Updated Security Considerations for the MD5 Message-Digest and the HMAC-MD5 Algorithms">[RFC6151]</cite></a> for details).
     4182      </p>
     4183      <p id="rfc.section.C.p.23">Remove ISO-8859-1 special-casing in <a href="#header.accept-charset" class="smpl">Accept-Charset</a>. (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.4" title="Accept-Charset">Section&nbsp;6.3.3</a>)
    41784184      </p>
    41794185      <p id="rfc.section.C.p.24">Remove base URI setting semantics for <a href="#header.content-location" class="smpl">Content-Location</a> due to poor implementation support, which was caused by too many broken servers emitting bogus Content-Location header fields,
    4180          and also the potentially undesirable effect of potentially breaking relative links in content-negotiated resources. (<a href="#header.content-location" id="rfc.xref.header.content-location.5" title="Content-Location">Section&nbsp;10.8</a>)
     4186         and also the potentially undesirable effect of potentially breaking relative links in content-negotiated resources. (<a href="#header.content-location" id="rfc.xref.header.content-location.5" title="Content-Location">Section&nbsp;3.2.4</a>)
    41814187      </p>
    41824188      <p id="rfc.section.C.p.25">Remove reference to non-existant identity transfer-coding value tokens. (<a href="#no.content-transfer-encoding" id="rfc.xref.no.content-transfer-encoding.1" title="No Content-Transfer-Encoding">Appendix&nbsp;A.5</a>)
    … …  
    49074913         <ul class="ind">
    49084914            <li><a id="rfc.index.1" href="#rfc.index.1"><b>1</b></a><ul>
    4909                   <li>100 Continue (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.100.1">7.1</a>, <a href="#rfc.iref.27"><b>7.2.1</b></a>, <a href="#rfc.xref.status.100.2">11.2.3</a></li>
    4910                   <li>100-continue (expect value)&nbsp;&nbsp;<a href="#rfc.iref.142"><b>10.11</b></a></li>
    4911                   <li>101 Switching Protocols (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.101.1">7.1</a>, <a href="#rfc.iref.28"><b>7.2.2</b></a>, <a href="#rfc.xref.status.101.2">11.2.3</a></li>
    4912                   <li>1xx Informational (status code class)&nbsp;&nbsp;<a href="#rfc.iref.26"><b>7.2</b></a></li>
     4915                  <li>100 Continue (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.100.1">7.1</a>, <a href="#rfc.iref.76"><b>7.2.1</b></a>, <a href="#rfc.xref.status.100.2">10.2.3</a></li>
     4916                  <li>100-continue (expect value)&nbsp;&nbsp;<a href="#rfc.iref.46"><b>6.1.2</b></a></li>
     4917                  <li>101 Switching Protocols (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.101.1">7.1</a>, <a href="#rfc.iref.77"><b>7.2.2</b></a>, <a href="#rfc.xref.status.101.2">10.2.3</a></li>
     4918                  <li>1xx Informational (status code class)&nbsp;&nbsp;<a href="#rfc.iref.75"><b>7.2</b></a></li>
    49134919               </ul>
    49144920            </li>
    49154921            <li><a id="rfc.index.2" href="#rfc.index.2"><b>2</b></a><ul>
    4916                   <li>200 OK (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.200.1">7.1</a>, <a href="#rfc.iref.30"><b>7.3.1</b></a>, <a href="#rfc.xref.status.200.2">11.2.3</a></li>
    4917                   <li>201 Created (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.201.1">7.1</a>, <a href="#rfc.iref.31"><b>7.3.2</b></a>, <a href="#rfc.xref.status.201.2">11.2.3</a></li>
    4918                   <li>202 Accepted (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.202.1">7.1</a>, <a href="#rfc.iref.32"><b>7.3.3</b></a>, <a href="#rfc.xref.status.202.2">11.2.3</a></li>
    4919                   <li>203 Non-Authoritative Information (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.203.1">7.1</a>, <a href="#rfc.iref.33"><b>7.3.4</b></a>, <a href="#rfc.xref.status.203.2">11.2.3</a>, <a href="#rfc.xref.status.203.3">C</a></li>
    4920                   <li>204 No Content (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.204.1">7.1</a>, <a href="#rfc.iref.34"><b>7.3.5</b></a>, <a href="#rfc.xref.status.204.2">11.2.3</a></li>
    4921                   <li>205 Reset Content (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.205.1">7.1</a>, <a href="#rfc.iref.35"><b>7.3.6</b></a>, <a href="#rfc.xref.status.205.2">11.2.3</a></li>
    4922                   <li>2xx Successful (status code class)&nbsp;&nbsp;<a href="#rfc.iref.29"><b>7.3</b></a></li>
     4922                  <li>200 OK (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.200.1">7.1</a>, <a href="#rfc.iref.79"><b>7.3.1</b></a>, <a href="#rfc.xref.status.200.2">10.2.3</a></li>
     4923                  <li>201 Created (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.201.1">7.1</a>, <a href="#rfc.iref.80"><b>7.3.2</b></a>, <a href="#rfc.xref.status.201.2">10.2.3</a></li>
     4924                  <li>202 Accepted (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.202.1">7.1</a>, <a href="#rfc.iref.81"><b>7.3.3</b></a>, <a href="#rfc.xref.status.202.2">10.2.3</a></li>
     4925                  <li>203 Non-Authoritative Information (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.203.1">7.1</a>, <a href="#rfc.iref.82"><b>7.3.4</b></a>, <a href="#rfc.xref.status.203.2">10.2.3</a>, <a href="#rfc.xref.status.203.3">C</a></li>
     4926                  <li>204 No Content (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.204.1">7.1</a>, <a href="#rfc.iref.83"><b>7.3.5</b></a>, <a href="#rfc.xref.status.204.2">10.2.3</a></li>
     4927                  <li>205 Reset Content (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.205.1">7.1</a>, <a href="#rfc.iref.84"><b>7.3.6</b></a>, <a href="#rfc.xref.status.205.2">10.2.3</a></li>
     4928                  <li>2xx Successful (status code class)&nbsp;&nbsp;<a href="#rfc.iref.78"><b>7.3</b></a></li>
    49234929               </ul>
    49244930            </li>
    49254931            <li><a id="rfc.index.3" href="#rfc.index.3"><b>3</b></a><ul>
    4926                   <li>300 Multiple Choices (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.300.1">7.1</a>, <a href="#rfc.iref.37"><b>7.4.1</b></a>, <a href="#rfc.xref.status.300.2">11.2.3</a></li>
    4927                   <li>301 Moved Permanently (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.301.1">7.1</a>, <a href="#rfc.iref.38"><b>7.4.2</b></a>, <a href="#rfc.xref.status.301.2">11.2.3</a>, <a href="#rfc.xref.status.301.3">C</a></li>
    4928                   <li>302 Found (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.302.1">7.1</a>, <a href="#rfc.iref.39"><b>7.4.3</b></a>, <a href="#rfc.xref.status.302.2">11.2.3</a>, <a href="#rfc.xref.status.302.3">C</a></li>
    4929                   <li>303 See Other (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.303.1">7.1</a>, <a href="#rfc.iref.40"><b>7.4.4</b></a>, <a href="#rfc.xref.status.303.2">11.2.3</a></li>
    4930                   <li>305 Use Proxy (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.305.1">7.1</a>, <a href="#rfc.iref.41"><b>7.4.5</b></a>, <a href="#rfc.xref.status.305.2">11.2.3</a>, <a href="#rfc.xref.status.305.3">C</a></li>
    4931                   <li>306 (Unused) (status code)&nbsp;&nbsp;<a href="#rfc.iref.42"><b>7.4.6</b></a>, <a href="#rfc.xref.status.306.1">11.2.3</a></li>
    4932                   <li>307 Temporary Redirect (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.307.1">7.1</a>, <a href="#rfc.iref.43"><b>7.4.7</b></a>, <a href="#rfc.xref.status.307.2">11.2.3</a>, <a href="#rfc.xref.status.307.3">C</a></li>
    4933                   <li>3xx Redirection (status code class)&nbsp;&nbsp;<a href="#rfc.iref.36"><b>7.4</b></a>, <a href="#rfc.xref.status.3xx.1">C</a></li>
     4932                  <li>300 Multiple Choices (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.300.1">7.1</a>, <a href="#rfc.iref.86"><b>7.4.1</b></a>, <a href="#rfc.xref.status.300.2">10.2.3</a></li>
     4933                  <li>301 Moved Permanently (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.301.1">7.1</a>, <a href="#rfc.iref.87"><b>7.4.2</b></a>, <a href="#rfc.xref.status.301.2">10.2.3</a>, <a href="#rfc.xref.status.301.3">C</a></li>
     4934                  <li>302 Found (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.302.1">7.1</a>, <a href="#rfc.iref.88"><b>7.4.3</b></a>, <a href="#rfc.xref.status.302.2">10.2.3</a>, <a href="#rfc.xref.status.302.3">C</a></li>
     4935                  <li>303 See Other (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.303.1">7.1</a>, <a href="#rfc.iref.89"><b>7.4.4</b></a>, <a href="#rfc.xref.status.303.2">10.2.3</a></li>
     4936                  <li>305 Use Proxy (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.305.1">7.1</a>, <a href="#rfc.iref.90"><b>7.4.5</b></a>, <a href="#rfc.xref.status.305.2">10.2.3</a>, <a href="#rfc.xref.status.305.3">C</a></li>
     4937                  <li>306 (Unused) (status code)&nbsp;&nbsp;<a href="#rfc.iref.91"><b>7.4.6</b></a>, <a href="#rfc.xref.status.306.1">10.2.3</a></li>
     4938                  <li>307 Temporary Redirect (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.307.1">7.1</a>, <a href="#rfc.iref.92"><b>7.4.7</b></a>, <a href="#rfc.xref.status.307.2">10.2.3</a>, <a href="#rfc.xref.status.307.3">C</a></li>
     4939                  <li>3xx Redirection (status code class)&nbsp;&nbsp;<a href="#rfc.iref.85"><b>7.4</b></a>, <a href="#rfc.xref.status.3xx.1">C</a></li>
    49344940               </ul>
    49354941            </li>
    49364942            <li><a id="rfc.index.4" href="#rfc.index.4"><b>4</b></a><ul>
    4937                   <li>400 Bad Request (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.400.1">7.1</a>, <a href="#rfc.iref.45"><b>7.5.1</b></a>, <a href="#rfc.xref.status.400.2">11.2.3</a></li>
    4938                   <li>402 Payment Required (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.402.1">7.1</a>, <a href="#rfc.iref.46"><b>7.5.2</b></a>, <a href="#rfc.xref.status.402.2">11.2.3</a></li>
    4939                   <li>403 Forbidden (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.403.1">7.1</a>, <a href="#rfc.iref.47"><b>7.5.3</b></a>, <a href="#rfc.xref.status.403.2">11.2.3</a></li>
    4940                   <li>404 Not Found (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.404.1">7.1</a>, <a href="#rfc.iref.48"><b>7.5.4</b></a>, <a href="#rfc.xref.status.404.2">11.2.3</a></li>
    4941                   <li>405 Method Not Allowed (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.405.1">7.1</a>, <a href="#rfc.iref.49"><b>7.5.5</b></a>, <a href="#rfc.xref.status.405.2">11.2.3</a></li>
    4942                   <li>406 Not Acceptable (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.406.1">7.1</a>, <a href="#rfc.iref.50"><b>7.5.6</b></a>, <a href="#rfc.xref.status.406.2">11.2.3</a></li>
    4943                   <li>408 Request Timeout (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.408.1">7.1</a>, <a href="#rfc.iref.51"><b>7.5.7</b></a>, <a href="#rfc.xref.status.408.2">11.2.3</a></li>
    4944                   <li>409 Conflict (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.409.1">7.1</a>, <a href="#rfc.iref.52"><b>7.5.8</b></a>, <a href="#rfc.xref.status.409.2">11.2.3</a></li>
    4945                   <li>410 Gone (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.410.1">7.1</a>, <a href="#rfc.iref.53"><b>7.5.9</b></a>, <a href="#rfc.xref.status.410.2">11.2.3</a></li>
    4946                   <li>411 Length Required (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.411.1">7.1</a>, <a href="#rfc.iref.54"><b>7.5.10</b></a>, <a href="#rfc.xref.status.411.2">11.2.3</a></li>
    4947                   <li>413 Request Representation Too Large (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.413.1">7.1</a>, <a href="#rfc.iref.55"><b>7.5.11</b></a>, <a href="#rfc.xref.status.413.2">11.2.3</a></li>
    4948                   <li>414 URI Too Long (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.414.1">7.1</a>, <a href="#rfc.iref.56"><b>7.5.12</b></a>, <a href="#rfc.xref.status.414.2">11.2.3</a></li>
    4949                   <li>415 Unsupported Media Type (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.415.1">7.1</a>, <a href="#rfc.iref.57"><b>7.5.13</b></a>, <a href="#rfc.xref.status.415.2">11.2.3</a></li>
    4950                   <li>417 Expectation Failed (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.417.1">7.1</a>, <a href="#rfc.iref.58"><b>7.5.14</b></a>, <a href="#rfc.xref.status.417.2">11.2.3</a></li>
    4951                   <li>426 Upgrade Required (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.426.1">7.1</a>, <a href="#rfc.iref.59"><b>7.5.15</b></a>, <a href="#rfc.xref.status.426.2">11.2.3</a>, <a href="#rfc.xref.status.426.3">C</a></li>
    4952                   <li>4xx Client Error (status code class)&nbsp;&nbsp;<a href="#rfc.iref.44"><b>7.5</b></a></li>
     4943                  <li>400 Bad Request (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.400.1">7.1</a>, <a href="#rfc.iref.94"><b>7.5.1</b></a>, <a href="#rfc.xref.status.400.2">10.2.3</a></li>
     4944                  <li>402 Payment Required (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.402.1">7.1</a>, <a href="#rfc.iref.95"><b>7.5.2</b></a>, <a href="#rfc.xref.status.402.2">10.2.3</a></li>
     4945                  <li>403 Forbidden (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.403.1">7.1</a>, <a href="#rfc.iref.96"><b>7.5.3</b></a>, <a href="#rfc.xref.status.403.2">10.2.3</a></li>
     4946                  <li>404 Not Found (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.404.1">7.1</a>, <a href="#rfc.iref.97"><b>7.5.4</b></a>, <a href="#rfc.xref.status.404.2">10.2.3</a></li>
     4947                  <li>405 Method Not Allowed (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.405.1">7.1</a>, <a href="#rfc.iref.98"><b>7.5.5</b></a>, <a href="#rfc.xref.status.405.2">10.2.3</a></li>
     4948                  <li>406 Not Acceptable (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.406.1">7.1</a>, <a href="#rfc.iref.99"><b>7.5.6</b></a>, <a href="#rfc.xref.status.406.2">10.2.3</a></li>
     4949                  <li>408 Request Timeout (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.408.1">7.1</a>, <a href="#rfc.iref.100"><b>7.5.7</b></a>, <a href="#rfc.xref.status.408.2">10.2.3</a></li>
     4950                  <li>409 Conflict (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.409.1">7.1</a>, <a href="#rfc.iref.101"><b>7.5.8</b></a>, <a href="#rfc.xref.status.409.2">10.2.3</a></li>
     4951                  <li>410 Gone (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.410.1">7.1</a>, <a href="#rfc.iref.102"><b>7.5.9</b></a>, <a href="#rfc.xref.status.410.2">10.2.3</a></li>
     4952                  <li>411 Length Required (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.411.1">7.1</a>, <a href="#rfc.iref.103"><b>7.5.10</b></a>, <a href="#rfc.xref.status.411.2">10.2.3</a></li>
     4953                  <li>413 Request Representation Too Large (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.413.1">7.1</a>, <a href="#rfc.iref.104"><b>7.5.11</b></a>, <a href="#rfc.xref.status.413.2">10.2.3</a></li>
     4954                  <li>414 URI Too Long (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.414.1">7.1</a>, <a href="#rfc.iref.105"><b>7.5.12</b></a>, <a href="#rfc.xref.status.414.2">10.2.3</a></li>
     4955                  <li>415 Unsupported Media Type (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.415.1">7.1</a>, <a href="#rfc.iref.106"><b>7.5.13</b></a>, <a href="#rfc.xref.status.415.2">10.2.3</a></li>
     4956                  <li>417 Expectation Failed (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.417.1">7.1</a>, <a href="#rfc.iref.107"><b>7.5.14</b></a>, <a href="#rfc.xref.status.417.2">10.2.3</a></li>
     4957                  <li>426 Upgrade Required (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.426.1">7.1</a>, <a href="#rfc.iref.108"><b>7.5.15</b></a>, <a href="#rfc.xref.status.426.2">10.2.3</a>, <a href="#rfc.xref.status.426.3">C</a></li>
     4958                  <li>4xx Client Error (status code class)&nbsp;&nbsp;<a href="#rfc.iref.93"><b>7.5</b></a></li>
    49534959               </ul>
    49544960            </li>
    49554961            <li><a id="rfc.index.5" href="#rfc.index.5"><b>5</b></a><ul>
    4956                   <li>500 Internal Server Error (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.500.1">7.1</a>, <a href="#rfc.iref.61"><b>7.6.1</b></a>, <a href="#rfc.xref.status.500.2">11.2.3</a></li>
    4957                   <li>501 Not Implemented (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.501.1">7.1</a>, <a href="#rfc.iref.62"><b>7.6.2</b></a>, <a href="#rfc.xref.status.501.2">11.2.3</a></li>
    4958                   <li>502 Bad Gateway (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.502.1">7.1</a>, <a href="#rfc.iref.63"><b>7.6.3</b></a>, <a href="#rfc.xref.status.502.2">11.2.3</a></li>
    4959                   <li>503 Service Unavailable (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.503.1">7.1</a>, <a href="#rfc.iref.64"><b>7.6.4</b></a>, <a href="#rfc.xref.status.503.2">11.2.3</a></li>
    4960                   <li>504 Gateway Timeout (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.504.1">7.1</a>, <a href="#rfc.iref.65"><b>7.6.5</b></a>, <a href="#rfc.xref.status.504.2">11.2.3</a></li>
    4961                   <li>505 HTTP Version Not Supported (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.505.1">7.1</a>, <a href="#rfc.iref.66"><b>7.6.6</b></a>, <a href="#rfc.xref.status.505.2">11.2.3</a></li>
    4962                   <li>5xx Server Error (status code class)&nbsp;&nbsp;<a href="#rfc.iref.60"><b>7.6</b></a></li>
     4962                  <li>500 Internal Server Error (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.500.1">7.1</a>, <a href="#rfc.iref.110"><b>7.6.1</b></a>, <a href="#rfc.xref.status.500.2">10.2.3</a></li>
     4963                  <li>501 Not Implemented (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.501.1">7.1</a>, <a href="#rfc.iref.111"><b>7.6.2</b></a>, <a href="#rfc.xref.status.501.2">10.2.3</a></li>
     4964                  <li>502 Bad Gateway (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.502.1">7.1</a>, <a href="#rfc.iref.112"><b>7.6.3</b></a>, <a href="#rfc.xref.status.502.2">10.2.3</a></li>
     4965                  <li>503 Service Unavailable (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.503.1">7.1</a>, <a href="#rfc.iref.113"><b>7.6.4</b></a>, <a href="#rfc.xref.status.503.2">10.2.3</a></li>
     4966                  <li>504 Gateway Timeout (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.504.1">7.1</a>, <a href="#rfc.iref.114"><b>7.6.5</b></a>, <a href="#rfc.xref.status.504.2">10.2.3</a></li>
     4967                  <li>505 HTTP Version Not Supported (status code)&nbsp;&nbsp;<a href="#rfc.xref.status.505.1">7.1</a>, <a href="#rfc.iref.115"><b>7.6.6</b></a>, <a href="#rfc.xref.status.505.2">10.2.3</a></li>
     4968                  <li>5xx Server Error (status code class)&nbsp;&nbsp;<a href="#rfc.iref.109"><b>7.6</b></a></li>
    49634969               </ul>
    49644970            </li>
    49654971            <li><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul>
    4966                   <li>Accept header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept.1">3.4.1</a>, <a href="#rfc.xref.header.accept.2">6.3</a>, <a href="#rfc.xref.header.accept.3">9.5</a>, <a href="#rfc.iref.a.1"><b>10.1</b></a>, <a href="#rfc.xref.header.accept.4">11.3.2</a></li>
    4967                   <li>Accept-Charset header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept-charset.1">3.4.1</a>, <a href="#rfc.xref.header.accept-charset.2">6.3</a>, <a href="#rfc.iref.a.2"><b>10.2</b></a>, <a href="#rfc.xref.header.accept-charset.3">11.3.2</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li>
    4968                   <li>Accept-Encoding header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept-encoding.1">3.4.1</a>, <a href="#rfc.xref.header.accept-encoding.2">6.3</a>, <a href="#rfc.xref.header.accept-encoding.3">9.4</a>, <a href="#rfc.iref.a.3"><b>10.3</b></a>, <a href="#rfc.xref.header.accept-encoding.4">11.3.2</a>, <a href="#rfc.xref.header.accept-encoding.5">11.4.2</a></li>
    4969                   <li>Accept-Language header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept-language.1">3.4.1</a>, <a href="#rfc.xref.header.accept-language.2">6.3</a>, <a href="#rfc.iref.a.4"><b>10.4</b></a>, <a href="#rfc.xref.header.accept-language.3">11.3.2</a></li>
    4970                   <li>Allow header field&nbsp;&nbsp;<a href="#rfc.xref.header.allow.1">5.1</a>, <a href="#rfc.xref.header.allow.2">8.4</a>, <a href="#rfc.iref.a.5"><b>10.5</b></a>, <a href="#rfc.xref.header.allow.3">11.3.2</a>, <a href="#rfc.xref.header.allow.4">C</a></li>
     4972                  <li>Accept header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept.1">3.5.1</a>, <a href="#rfc.xref.header.accept.2">6.3</a>, <a href="#rfc.iref.a.1"><b>6.3.2</b></a>, <a href="#rfc.xref.header.accept.3">9.5</a>, <a href="#rfc.xref.header.accept.4">10.3.2</a></li>
     4973                  <li>Accept-Charset header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept-charset.1">3.5.1</a>, <a href="#rfc.xref.header.accept-charset.2">6.3</a>, <a href="#rfc.iref.a.2"><b>6.3.3</b></a>, <a href="#rfc.xref.header.accept-charset.3">10.3.2</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li>
     4974                  <li>Accept-Encoding header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept-encoding.1">3.5.1</a>, <a href="#rfc.xref.header.accept-encoding.2">6.3</a>, <a href="#rfc.iref.a.3"><b>6.3.4</b></a>, <a href="#rfc.xref.header.accept-encoding.3">9.4</a>, <a href="#rfc.xref.header.accept-encoding.4">10.3.2</a>, <a href="#rfc.xref.header.accept-encoding.5">10.4.2</a></li>
     4975                  <li>Accept-Language header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept-language.1">3.5.1</a>, <a href="#rfc.xref.header.accept-language.2">6.3</a>, <a href="#rfc.iref.a.4"><b>6.3.5</b></a>, <a href="#rfc.xref.header.accept-language.3">10.3.2</a></li>
     4976                  <li>Allow header field&nbsp;&nbsp;<a href="#rfc.xref.header.allow.1">5.1</a>, <a href="#rfc.xref.header.allow.2">8.4</a>, <a href="#rfc.iref.a.5"><b>8.4.1</b></a>, <a href="#rfc.xref.header.allow.3">10.3.2</a>, <a href="#rfc.xref.header.allow.4">C</a></li>
    49714977               </ul>
    49724978            </li>
    49734979            <li><a id="rfc.index.C" href="#rfc.index.C"><b>C</b></a><ul>
    4974                   <li>cacheable&nbsp;&nbsp;<a href="#rfc.iref.c.2"><b>5.2.3</b></a></li>
     4980                  <li>cacheable&nbsp;&nbsp;<a href="#rfc.iref.c.6"><b>5.2.3</b></a></li>
    49754981                  <li>Coding Format&nbsp;&nbsp;
    49764982                     <ul>
    4977                         <li>compress&nbsp;&nbsp;<a href="#rfc.iref.c.5">9.4</a></li>
    4978                         <li>deflate&nbsp;&nbsp;<a href="#rfc.iref.c.6">9.4</a></li>
    4979                         <li>gzip&nbsp;&nbsp;<a href="#rfc.iref.c.7">9.4</a></li>
     4983                        <li>compress&nbsp;&nbsp;<a href="#rfc.iref.c.9">9.4</a></li>
     4984                        <li>deflate&nbsp;&nbsp;<a href="#rfc.iref.c.10">9.4</a></li>
     4985                        <li>gzip&nbsp;&nbsp;<a href="#rfc.iref.c.11">9.4</a></li>
    49804986                     </ul>
    49814987                  </li>
    4982                   <li>compress (Coding Format)&nbsp;&nbsp;<a href="#rfc.iref.c.4">9.4</a></li>
    4983                   <li>CONNECT method&nbsp;&nbsp;<a href="#rfc.xref.CONNECT.1">5.1</a>, <a href="#rfc.iref.c.3"><b>5.3.6</b></a>, <a href="#rfc.xref.CONNECT.2">11.1.3</a>, <a href="#rfc.xref.CONNECT.3">C</a></li>
     4988                  <li>compress (Coding Format)&nbsp;&nbsp;<a href="#rfc.iref.c.8">9.4</a></li>
     4989                  <li>CONNECT method&nbsp;&nbsp;<a href="#rfc.xref.CONNECT.1">5.1</a>, <a href="#rfc.iref.c.7"><b>5.3.6</b></a>, <a href="#rfc.xref.CONNECT.2">10.1.3</a>, <a href="#rfc.xref.CONNECT.3">C</a></li>
    49844990                  <li>content negotiation&nbsp;&nbsp;<a href="#rfc.iref.c.1">1</a></li>
    4985                   <li>Content-Encoding header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-encoding.1">3.2</a>, <a href="#rfc.xref.header.content-encoding.2">9.4</a>, <a href="#rfc.iref.c.8"><b>10.6</b></a>, <a href="#rfc.xref.header.content-encoding.3">11.3.2</a></li>
    4986                   <li>Content-Language header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-language.1">3.2</a>, <a href="#rfc.iref.c.9"><b>10.7</b></a>, <a href="#rfc.xref.header.content-language.2">11.3.2</a></li>
    4987                   <li>Content-Location header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-location.1">3.2</a>, <a href="#rfc.xref.header.content-location.2">5.3.3</a>, <a href="#rfc.iref.c.10"><b>10.8</b></a>, <a href="#rfc.xref.header.content-location.3">10.13</a>, <a href="#rfc.xref.header.content-location.4">11.3.2</a>, <a href="#rfc.xref.header.content-location.5">C</a></li>
     4991                  <li>Content-Encoding header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-encoding.1">3.2</a>, <a href="#rfc.iref.c.3"><b>3.2.2</b></a>, <a href="#rfc.xref.header.content-encoding.2">9.4</a>, <a href="#rfc.xref.header.content-encoding.3">10.3.2</a></li>
     4992                  <li>Content-Language header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-language.1">3.2</a>, <a href="#rfc.iref.c.4"><b>3.2.3</b></a>, <a href="#rfc.xref.header.content-language.2">10.3.2</a></li>
     4993                  <li>Content-Location header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-location.1">3.2</a>, <a href="#rfc.iref.c.5"><b>3.2.4</b></a>, <a href="#rfc.xref.header.content-location.2">5.3.3</a>, <a href="#rfc.xref.header.content-location.3">8.1.1</a>, <a href="#rfc.xref.header.content-location.4">10.3.2</a>, <a href="#rfc.xref.header.content-location.5">C</a></li>
    49884994                  <li>Content-Transfer-Encoding header field&nbsp;&nbsp;<a href="#rfc.iref.c.12">A.5</a>, <a href="#rfc.xref.no.content-transfer-encoding.1">C</a></li>
    4989                   <li>Content-Type header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-type.1">3.2</a>, <a href="#rfc.xref.header.content-type.2">7</a>, <a href="#rfc.xref.header.content-type.3">9.5</a>, <a href="#rfc.iref.c.11"><b>10.9</b></a>, <a href="#rfc.xref.header.content-type.4">11.3.1</a>, <a href="#rfc.xref.header.content-type.5">11.3.2</a></li>
     4995                  <li>Content-Type header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-type.1">3.2</a>, <a href="#rfc.iref.c.2"><b>3.2.1</b></a>, <a href="#rfc.xref.header.content-type.2">7</a>, <a href="#rfc.xref.header.content-type.3">9.5</a>, <a href="#rfc.xref.header.content-type.4">10.3.1</a>, <a href="#rfc.xref.header.content-type.5">10.3.2</a></li>
    49904996               </ul>
    49914997            </li>
    49924998            <li><a id="rfc.index.D" href="#rfc.index.D"><b>D</b></a><ul>
    4993                   <li>Date header field&nbsp;&nbsp;<a href="#rfc.xref.header.date.1">8.2</a>, <a href="#rfc.iref.d.3"><b>10.10</b></a>, <a href="#rfc.xref.header.date.2">11.3.2</a></li>
    4994                   <li>deflate (Coding Format)&nbsp;&nbsp;<a href="#rfc.iref.d.2">9.4</a></li>
    4995                   <li>DELETE method&nbsp;&nbsp;<a href="#rfc.xref.DELETE.1">5.1</a>, <a href="#rfc.iref.d.1"><b>5.3.5</b></a>, <a href="#rfc.xref.DELETE.2">11.1.3</a></li>
     4999                  <li>Date header field&nbsp;&nbsp;<a href="#rfc.xref.header.date.1">8.2</a>, <a href="#rfc.iref.d.2"><b>8.2.1</b></a>, <a href="#rfc.xref.header.date.2">10.3.2</a></li>
     5000                  <li>deflate (Coding Format)&nbsp;&nbsp;<a href="#rfc.iref.d.3">9.4</a></li>
     5001                  <li>DELETE method&nbsp;&nbsp;<a href="#rfc.xref.DELETE.1">5.1</a>, <a href="#rfc.iref.d.1"><b>5.3.5</b></a>, <a href="#rfc.xref.DELETE.2">10.1.3</a></li>
    49965002               </ul>
    49975003            </li>
    49985004            <li><a id="rfc.index.E" href="#rfc.index.E"><b>E</b></a><ul>
    4999                   <li>Expect header field&nbsp;&nbsp;<a href="#rfc.xref.header.expect.1">6.1</a>, <a href="#rfc.xref.header.expect.2">7.5.14</a>, <a href="#rfc.iref.e.1"><b>10.11</b></a>, <a href="#rfc.xref.header.expect.3">11.3.2</a>, <a href="#rfc.xref.header.expect.4">C</a></li>
     5005                  <li>Expect header field&nbsp;&nbsp;<a href="#rfc.xref.header.expect.1">6.1</a>, <a href="#rfc.iref.e.1"><b>6.1.2</b></a>, <a href="#rfc.xref.header.expect.2">7.5.14</a>, <a href="#rfc.xref.header.expect.3">10.3.2</a>, <a href="#rfc.xref.header.expect.4">C</a></li>
    50005006                  <li>Expect Values&nbsp;&nbsp;
    50015007                     <ul>
    5002                         <li>100-continue&nbsp;&nbsp;<a href="#rfc.iref.e.2"><b>10.11</b></a></li>
     5008                        <li>100-continue&nbsp;&nbsp;<a href="#rfc.iref.e.2"><b>6.1.2</b></a></li>
    50035009                     </ul>
    50045010                  </li>
    … …  
    50065012            </li>
    50075013            <li><a id="rfc.index.F" href="#rfc.index.F"><b>F</b></a><ul>
    5008                   <li>From header field&nbsp;&nbsp;<a href="#rfc.xref.header.from.1">6.5</a>, <a href="#rfc.iref.f.1"><b>10.12</b></a>, <a href="#rfc.xref.header.from.2">11.3.2</a></li>
     5014                  <li>From header field&nbsp;&nbsp;<a href="#rfc.xref.header.from.1">6.5</a>, <a href="#rfc.iref.f.1"><b>6.5.1</b></a>, <a href="#rfc.xref.header.from.2">10.3.2</a></li>
    50095015               </ul>
    50105016            </li>
    50115017            <li><a id="rfc.index.G" href="#rfc.index.G"><b>G</b></a><ul>
    5012                   <li>GET method&nbsp;&nbsp;<a href="#rfc.xref.GET.1">5.1</a>, <a href="#rfc.iref.g.4"><b>5.3.1</b></a>, <a href="#rfc.xref.GET.2">11.1.3</a></li>
     5018                  <li>GET method&nbsp;&nbsp;<a href="#rfc.xref.GET.1">5.1</a>, <a href="#rfc.iref.g.6"><b>5.3.1</b></a>, <a href="#rfc.xref.GET.2">10.1.3</a></li>
    50135019                  <li><tt>Grammar</tt>&nbsp;&nbsp;
    50145020                     <ul>
    5015                         <li><tt>Accept</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.33"><b>10.1</b></a></li>
    5016                         <li><tt>Accept-Charset</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.37"><b>10.2</b></a></li>
    5017                         <li><tt>Accept-Encoding</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.38"><b>10.3</b></a></li>
    5018                         <li><tt>accept-ext</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.36"><b>10.1</b></a></li>
    5019                         <li><tt>Accept-Language</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.40"><b>10.4</b></a></li>
    5020                         <li><tt>accept-params</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.35"><b>10.1</b></a></li>
    5021                         <li><tt>Allow</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.42"><b>10.5</b></a></li>
    5022                         <li><tt>asctime-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.20"><b>9.1</b></a></li>
    5023                         <li><tt>attribute</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.30"><b>9.5</b></a></li>
    5024                         <li><tt>charset</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.23"><b>9.3</b></a></li>
    5025                         <li><tt>codings</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.39"><b>10.3</b></a></li>
    5026                         <li><tt>content-coding</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.24"><b>9.4</b></a></li>
    5027                         <li><tt>Content-Encoding</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.43"><b>10.6</b></a></li>
    5028                         <li><tt>Content-Language</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.44"><b>10.7</b></a></li>
    5029                         <li><tt>Content-Location</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.45"><b>10.8</b></a></li>
    5030                         <li><tt>Content-Type</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.46"><b>10.9</b></a></li>
    5031                         <li><tt>Date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.47"><b>10.10</b></a></li>
    5032                         <li><tt>date1</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.7"><b>9.1</b></a></li>
    5033                         <li><tt>day</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.14"><b>9.1</b></a></li>
    5034                         <li><tt>day-name</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.12"><b>9.1</b></a></li>
    5035                         <li><tt>day-name-l</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.13"><b>9.1</b></a></li>
    5036                         <li><tt>delta-seconds</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.58"><b>10.16</b></a></li>
    5037                         <li><tt>Expect</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.48"><b>10.11</b></a></li>
    5038                         <li><tt>expect-name</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.52"><b>10.11</b></a></li>
    5039                         <li><tt>expect-param</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.50"><b>10.11</b></a></li>
    5040                         <li><tt>expect-value</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.51"><b>10.11</b></a></li>
    5041                         <li><tt>expectation</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.49"><b>10.11</b></a></li>
    5042                         <li><tt>From</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.53"><b>10.12</b></a></li>
    5043                         <li><tt>GMT</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.17"><b>9.1</b></a></li>
    5044                         <li><tt>hour</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.9"><b>9.1</b></a></li>
    5045                         <li><tt>HTTP-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.5"><b>9.1</b></a></li>
    5046                         <li><tt>language-range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.41"><b>10.4</b></a></li>
    5047                         <li><tt>language-tag</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.32"><b>9.6</b></a></li>
    5048                         <li><tt>Location</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.54"><b>10.13</b></a></li>
    5049                         <li><tt>Max-Forwards</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.55"><b>10.14</b></a></li>
    5050                         <li><tt>media-range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.34"><b>10.1</b></a></li>
    5051                         <li><tt>media-type</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.26"><b>9.5</b></a></li>
    5052                         <li><tt>method</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.3"><b>5.1</b></a></li>
     5021                        <li><tt>Accept</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.15"><b>6.3.2</b></a></li>
     5022                        <li><tt>Accept-Charset</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.19"><b>6.3.3</b></a></li>
     5023                        <li><tt>Accept-Encoding</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.20"><b>6.3.4</b></a></li>
     5024                        <li><tt>accept-ext</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.18"><b>6.3.2</b></a></li>
     5025                        <li><tt>Accept-Language</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.22"><b>6.3.5</b></a></li>
     5026                        <li><tt>accept-params</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.17"><b>6.3.2</b></a></li>
     5027                        <li><tt>Allow</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.31"><b>8.4.1</b></a></li>
     5028                        <li><tt>asctime-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.48"><b>9.1</b></a></li>
     5029                        <li><tt>attribute</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.58"><b>9.5</b></a></li>
     5030                        <li><tt>charset</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.51"><b>9.3</b></a></li>
     5031                        <li><tt>codings</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.21"><b>6.3.4</b></a></li>
     5032                        <li><tt>content-coding</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.52"><b>9.4</b></a></li>
     5033                        <li><tt>Content-Encoding</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.2"><b>3.2.2</b></a></li>
     5034                        <li><tt>Content-Language</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.3"><b>3.2.3</b></a></li>
     5035                        <li><tt>Content-Location</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.4"><b>3.2.4</b></a></li>
     5036                        <li><tt>Content-Type</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.1"><b>3.2.1</b></a></li>
     5037                        <li><tt>Date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.30"><b>8.2.1</b></a></li>
     5038                        <li><tt>date1</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.35"><b>9.1</b></a></li>
     5039                        <li><tt>day</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.42"><b>9.1</b></a></li>
     5040                        <li><tt>day-name</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.40"><b>9.1</b></a></li>
     5041                        <li><tt>day-name-l</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.41"><b>9.1</b></a></li>
     5042                        <li><tt>delta-seconds</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.29"><b>8.1.2</b></a></li>
     5043                        <li><tt>Expect</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.8"><b>6.1.2</b></a></li>
     5044                        <li><tt>expect-name</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.12"><b>6.1.2</b></a></li>
     5045                        <li><tt>expect-param</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.10"><b>6.1.2</b></a></li>
     5046                        <li><tt>expect-value</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.11"><b>6.1.2</b></a></li>
     5047                        <li><tt>expectation</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.9"><b>6.1.2</b></a></li>
     5048                        <li><tt>From</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.24"><b>6.5.1</b></a></li>
     5049                        <li><tt>GMT</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.45"><b>9.1</b></a></li>
     5050                        <li><tt>hour</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.37"><b>9.1</b></a></li>
     5051                        <li><tt>HTTP-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.33"><b>9.1</b></a></li>
     5052                        <li><tt>language-range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.23"><b>6.3.5</b></a></li>
     5053                        <li><tt>language-tag</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.60"><b>9.6</b></a></li>
     5054                        <li><tt>Location</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.27"><b>8.1.1</b></a></li>
     5055                        <li><tt>Max-Forwards</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.7"><b>6.1.1</b></a></li>
     5056                        <li><tt>media-range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.16"><b>6.3.2</b></a></li>
     5057                        <li><tt>media-type</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.54"><b>9.5</b></a></li>
     5058                        <li><tt>method</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.5"><b>5.1</b></a></li>
    50535059                        <li><tt>MIME-Version</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.61"><b>A.1</b></a></li>
    5054                         <li><tt>minute</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.10"><b>9.1</b></a></li>
    5055                         <li><tt>month</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.15"><b>9.1</b></a></li>
    5056                         <li><tt>obs-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.18"><b>9.1</b></a></li>
    5057                         <li><tt>parameter</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.29"><b>9.5</b></a></li>
    5058                         <li><tt>product</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.21"><b>9.2</b></a></li>
    5059                         <li><tt>product-version</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.22"><b>9.2</b></a></li>
    5060                         <li><tt>qvalue</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.2"><b>3.4.3</b></a></li>
    5061                         <li><tt>Referer</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.56"><b>10.15</b></a></li>
    5062                         <li><tt>Retry-After</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.57"><b>10.16</b></a></li>
    5063                         <li><tt>rfc1123-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.6"><b>9.1</b></a></li>
    5064                         <li><tt>rfc850-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.19"><b>9.1</b></a></li>
    5065                         <li><tt>second</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.11"><b>9.1</b></a></li>
    5066                         <li><tt>Server</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.59"><b>10.17</b></a></li>
    5067                         <li><tt>subtype</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.28"><b>9.5</b></a></li>
    5068                         <li><tt>time-of-day</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.8"><b>9.1</b></a></li>
    5069                         <li><tt>type</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.27"><b>9.5</b></a></li>
    5070                         <li><tt>User-Agent</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.60"><b>10.18</b></a></li>
    5071                         <li><tt>value</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.31"><b>9.5</b></a></li>
    5072                         <li><tt>weight</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.1"><b>3.4.3</b></a></li>
    5073                         <li><tt>year</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.16"><b>9.1</b></a></li>
     5060                        <li><tt>minute</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.38"><b>9.1</b></a></li>
     5061                        <li><tt>month</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.43"><b>9.1</b></a></li>
     5062                        <li><tt>obs-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.46"><b>9.1</b></a></li>
     5063                        <li><tt>parameter</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.57"><b>9.5</b></a></li>
     5064                        <li><tt>product</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.49"><b>9.2</b></a></li>
     5065                        <li><tt>product-version</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.50"><b>9.2</b></a></li>
     5066                        <li><tt>qvalue</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.14"><b>6.3.1</b></a></li>
     5067                        <li><tt>Referer</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.25"><b>6.5.2</b></a></li>
     5068                        <li><tt>Retry-After</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.28"><b>8.1.2</b></a></li>
     5069                        <li><tt>rfc1123-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.34"><b>9.1</b></a></li>
     5070                        <li><tt>rfc850-date</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.47"><b>9.1</b></a></li>
     5071                        <li><tt>second</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.39"><b>9.1</b></a></li>
     5072                        <li><tt>Server</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.32"><b>8.4.2</b></a></li>
     5073                        <li><tt>subtype</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.56"><b>9.5</b></a></li>
     5074                        <li><tt>time-of-day</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.36"><b>9.1</b></a></li>
     5075                        <li><tt>type</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.55"><b>9.5</b></a></li>
     5076                        <li><tt>User-Agent</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.26"><b>6.5.3</b></a></li>
     5077                        <li><tt>value</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.59"><b>9.5</b></a></li>
     5078                        <li><tt>weight</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.13"><b>6.3.1</b></a></li>
     5079                        <li><tt>year</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.44"><b>9.1</b></a></li>
    50745080                     </ul>
    50755081                  </li>
    5076                   <li>gzip (Coding Format)&nbsp;&nbsp;<a href="#rfc.iref.g.25">9.4</a></li>
     5082                  <li>gzip (Coding Format)&nbsp;&nbsp;<a href="#rfc.iref.g.53">9.4</a></li>
    50775083               </ul>
    50785084            </li>
    50795085            <li><a id="rfc.index.H" href="#rfc.index.H"><b>H</b></a><ul>
    5080                   <li>HEAD method&nbsp;&nbsp;<a href="#rfc.xref.HEAD.1">5.1</a>, <a href="#rfc.iref.h.1"><b>5.3.2</b></a>, <a href="#rfc.xref.HEAD.2">11.1.3</a></li>
     5086                  <li>HEAD method&nbsp;&nbsp;<a href="#rfc.xref.HEAD.1">5.1</a>, <a href="#rfc.iref.h.5"><b>5.3.2</b></a>, <a href="#rfc.xref.HEAD.2">10.1.3</a></li>
    50815087                  <li>Header Fields&nbsp;&nbsp;
    50825088                     <ul>
    5083                         <li>Accept&nbsp;&nbsp;<a href="#rfc.xref.header.accept.1">3.4.1</a>, <a href="#rfc.xref.header.accept.2">6.3</a>, <a href="#rfc.xref.header.accept.3">9.5</a>, <a href="#rfc.iref.h.2"><b>10.1</b></a>, <a href="#rfc.xref.header.accept.4">11.3.2</a></li>
    5084                         <li>Accept-Charset&nbsp;&nbsp;<a href="#rfc.xref.header.accept-charset.1">3.4.1</a>, <a href="#rfc.xref.header.accept-charset.2">6.3</a>, <a href="#rfc.iref.h.3"><b>10.2</b></a>, <a href="#rfc.xref.header.accept-charset.3">11.3.2</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li>
    5085                         <li>Accept-Encoding&nbsp;&nbsp;<a href="#rfc.xref.header.accept-encoding.1">3.4.1</a>, <a href="#rfc.xref.header.accept-encoding.2">6.3</a>, <a href="#rfc.xref.header.accept-encoding.3">9.4</a>, <a href="#rfc.iref.h.4"><b>10.3</b></a>, <a href="#rfc.xref.header.accept-encoding.4">11.3.2</a>, <a href="#rfc.xref.header.accept-encoding.5">11.4.2</a></li>
    5086                         <li>Accept-Language&nbsp;&nbsp;<a href="#rfc.xref.header.accept-language.1">3.4.1</a>, <a href="#rfc.xref.header.accept-language.2">6.3</a>, <a href="#rfc.iref.h.5"><b>10.4</b></a>, <a href="#rfc.xref.header.accept-language.3">11.3.2</a></li>
    5087                         <li>Allow&nbsp;&nbsp;<a href="#rfc.xref.header.allow.1">5.1</a>, <a href="#rfc.xref.header.allow.2">8.4</a>, <a href="#rfc.iref.h.6"><b>10.5</b></a>, <a href="#rfc.xref.header.allow.3">11.3.2</a>, <a href="#rfc.xref.header.allow.4">C</a></li>
    5088                         <li>Content-Encoding&nbsp;&nbsp;<a href="#rfc.xref.header.content-encoding.1">3.2</a>, <a href="#rfc.xref.header.content-encoding.2">9.4</a>, <a href="#rfc.iref.h.7"><b>10.6</b></a>, <a href="#rfc.xref.header.content-encoding.3">11.3.2</a></li>
    5089                         <li>Content-Language&nbsp;&nbsp;<a href="#rfc.xref.header.content-language.1">3.2</a>, <a href="#rfc.iref.h.8"><b>10.7</b></a>, <a href="#rfc.xref.header.content-language.2">11.3.2</a></li>
    5090                         <li>Content-Location&nbsp;&nbsp;<a href="#rfc.xref.header.content-location.1">3.2</a>, <a href="#rfc.xref.header.content-location.2">5.3.3</a>, <a href="#rfc.iref.h.9"><b>10.8</b></a>, <a href="#rfc.xref.header.content-location.3">10.13</a>, <a href="#rfc.xref.header.content-location.4">11.3.2</a>, <a href="#rfc.xref.header.content-location.5">C</a></li>
     5089                        <li>Accept&nbsp;&nbsp;<a href="#rfc.xref.header.accept.1">3.5.1</a>, <a href="#rfc.xref.header.accept.2">6.3</a>, <a href="#rfc.iref.h.8"><b>6.3.2</b></a>, <a href="#rfc.xref.header.accept.3">9.5</a>, <a href="#rfc.xref.header.accept.4">10.3.2</a></li>
     5090                        <li>Accept-Charset&nbsp;&nbsp;<a href="#rfc.xref.header.accept-charset.1">3.5.1</a>, <a href="#rfc.xref.header.accept-charset.2">6.3</a>, <a href="#rfc.iref.h.9"><b>6.3.3</b></a>, <a href="#rfc.xref.header.accept-charset.3">10.3.2</a>, <a href="#rfc.xref.header.accept-charset.4">C</a></li>
     5091                        <li>Accept-Encoding&nbsp;&nbsp;<a href="#rfc.xref.header.accept-encoding.1">3.5.1</a>, <a href="#rfc.xref.header.accept-encoding.2">6.3</a>, <a href="#rfc.iref.h.10"><b>6.3.4</b></a>, <a href="#rfc.xref.header.accept-encoding.3">9.4</a>, <a href="#rfc.xref.header.accept-encoding.4">10.3.2</a>, <a href="#rfc.xref.header.accept-encoding.5">10.4.2</a></li>
     5092                        <li>Accept-Language&nbsp;&nbsp;<a href="#rfc.xref.header.accept-language.1">3.5.1</a>, <a href="#rfc.xref.header.accept-language.2">6.3</a>, <a href="#rfc.iref.h.11"><b>6.3.5</b></a>, <a href="#rfc.xref.header.accept-language.3">10.3.2</a></li>
     5093                        <li>Allow&nbsp;&nbsp;<a href="#rfc.xref.header.allow.1">5.1</a>, <a href="#rfc.xref.header.allow.2">8.4</a>, <a href="#rfc.iref.h.18"><b>8.4.1</b></a>, <a href="#rfc.xref.header.allow.3">10.3.2</a>, <a href="#rfc.xref.header.allow.4">C</a></li>
     5094                        <li>Content-Encoding&nbsp;&nbsp;<a href="#rfc.xref.header.content-encoding.1">3.2</a>, <a href="#rfc.iref.h.2"><b>3.2.2</b></a>, <a href="#rfc.xref.header.content-encoding.2">9.4</a>, <a href="#rfc.xref.header.content-encoding.3">10.3.2</a></li>
     5095                        <li>Content-Language&nbsp;&nbsp;<a href="#rfc.xref.header.content-language.1">3.2</a>, <a href="#rfc.iref.h.3"><b>3.2.3</b></a>, <a href="#rfc.xref.header.content-language.2">10.3.2</a></li>
     5096                        <li>Content-Location&nbsp;&nbsp;<a href="#rfc.xref.header.content-location.1">3.2</a>, <a href="#rfc.iref.h.4"><b>3.2.4</b></a>, <a href="#rfc.xref.header.content-location.2">5.3.3</a>, <a href="#rfc.xref.header.content-location.3">8.1.1</a>, <a href="#rfc.xref.header.content-location.4">10.3.2</a>, <a href="#rfc.xref.header.content-location.5">C</a></li>
    50915097                        <li>Content-Transfer-Encoding&nbsp;&nbsp;<a href="#rfc.iref.h.21">A.5</a>, <a href="#rfc.xref.no.content-transfer-encoding.1">C</a></li>
    5092                         <li>Content-Type&nbsp;&nbsp;<a href="#rfc.xref.header.content-type.1">3.2</a>, <a href="#rfc.xref.header.content-type.2">7</a>, <a href="#rfc.xref.header.content-type.3">9.5</a>, <a href="#rfc.iref.h.10"><b>10.9</b></a>, <a href="#rfc.xref.header.content-type.4">11.3.1</a>, <a href="#rfc.xref.header.content-type.5">11.3.2</a></li>
    5093                         <li>Date&nbsp;&nbsp;<a href="#rfc.xref.header.date.1">8.2</a>, <a href="#rfc.iref.h.11"><b>10.10</b></a>, <a href="#rfc.xref.header.date.2">11.3.2</a></li>
    5094                         <li>Expect&nbsp;&nbsp;<a href="#rfc.xref.header.expect.1">6.1</a>, <a href="#rfc.xref.header.expect.2">7.5.14</a>, <a href="#rfc.iref.h.12"><b>10.11</b></a>, <a href="#rfc.xref.header.expect.3">11.3.2</a>, <a href="#rfc.xref.header.expect.4">C</a></li>
    5095                         <li>From&nbsp;&nbsp;<a href="#rfc.xref.header.from.1">6.5</a>, <a href="#rfc.iref.h.13"><b>10.12</b></a>, <a href="#rfc.xref.header.from.2">11.3.2</a></li>
    5096                         <li>Location&nbsp;&nbsp;<a href="#rfc.xref.header.location.1">5.3.3</a>, <a href="#rfc.xref.header.location.2">7.4</a>, <a href="#rfc.xref.header.location.3">8.1</a>, <a href="#rfc.iref.h.14"><b>10.13</b></a>, <a href="#rfc.xref.header.location.4">11.3.2</a>, <a href="#rfc.xref.header.location.5">C</a></li>
    5097                         <li>Max-Forwards&nbsp;&nbsp;<a href="#rfc.xref.header.max-forwards.1">5.3.7</a>, <a href="#rfc.xref.header.max-forwards.2">5.3.8</a>, <a href="#rfc.xref.header.max-forwards.3">6.1</a>, <a href="#rfc.iref.h.15"><b>10.14</b></a>, <a href="#rfc.xref.header.max-forwards.4">11.3.2</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li>
    5098                         <li>MIME-Version&nbsp;&nbsp;<a href="#rfc.xref.mime-version.1">11.3.2</a>, <a href="#rfc.iref.h.20"><b>A.1</b></a></li>
    5099                         <li>Referer&nbsp;&nbsp;<a href="#rfc.xref.header.referer.1">6.5</a>, <a href="#rfc.iref.h.16"><b>10.15</b></a>, <a href="#rfc.xref.header.referer.2">11.3.2</a>, <a href="#rfc.xref.header.referer.3">C</a></li>
    5100                         <li>Retry-After&nbsp;&nbsp;<a href="#rfc.xref.header.retry-after.1">7.6.4</a>, <a href="#rfc.xref.header.retry-after.2">8.1</a>, <a href="#rfc.iref.h.17"><b>10.16</b></a>, <a href="#rfc.xref.header.retry-after.3">11.3.2</a></li>
    5101                         <li>Server&nbsp;&nbsp;<a href="#rfc.xref.header.server.1">8.4</a>, <a href="#rfc.iref.h.18"><b>10.17</b></a>, <a href="#rfc.xref.header.server.2">11.3.2</a>, <a href="#rfc.xref.header.server.3">12.1</a>, <a href="#rfc.xref.header.server.4">C</a></li>
    5102                         <li>User-Agent&nbsp;&nbsp;<a href="#rfc.xref.header.user-agent.1">3.4.1</a>, <a href="#rfc.xref.header.user-agent.2">6.5</a>, <a href="#rfc.iref.h.19"><b>10.18</b></a>, <a href="#rfc.xref.header.user-agent.3">11.3.2</a>, <a href="#rfc.xref.header.user-agent.4">12.1</a></li>
     5098                        <li>Content-Type&nbsp;&nbsp;<a href="#rfc.xref.header.content-type.1">3.2</a>, <a href="#rfc.iref.h.1"><b>3.2.1</b></a>, <a href="#rfc.xref.header.content-type.2">7</a>, <a href="#rfc.xref.header.content-type.3">9.5</a>, <a href="#rfc.xref.header.content-type.4">10.3.1</a>, <a href="#rfc.xref.header.content-type.5">10.3.2</a></li>
     5099                        <li>Date&nbsp;&nbsp;<a href="#rfc.xref.header.date.1">8.2</a>, <a href="#rfc.iref.h.17"><b>8.2.1</b></a>, <a href="#rfc.xref.header.date.2">10.3.2</a></li>
     5100                        <li>Expect&nbsp;&nbsp;<a href="#rfc.xref.header.expect.1">6.1</a>, <a href="#rfc.iref.h.7"><b>6.1.2</b></a>, <a href="#rfc.xref.header.expect.2">7.5.14</a>, <a href="#rfc.xref.header.expect.3">10.3.2</a>, <a href="#rfc.xref.header.expect.4">C</a></li>
     5101                        <li>From&nbsp;&nbsp;<a href="#rfc.xref.header.from.1">6.5</a>, <a href="#rfc.iref.h.12"><b>6.5.1</b></a>, <a href="#rfc.xref.header.from.2">10.3.2</a></li>
     5102                        <li>Location&nbsp;&nbsp;<a href="#rfc.xref.header.location.1">5.3.3</a>, <a href="#rfc.xref.header.location.2">7.4</a>, <a href="#rfc.xref.header.location.3">8.1</a>, <a href="#rfc.iref.h.15"><b>8.1.1</b></a>, <a href="#rfc.xref.header.location.4">10.3.2</a>, <a href="#rfc.xref.header.location.5">C</a></li>
     5103                        <li>Max-Forwards&nbsp;&nbsp;<a href="#rfc.xref.header.max-forwards.1">5.3.7</a>, <a href="#rfc.xref.header.max-forwards.2">5.3.8</a>, <a href="#rfc.xref.header.max-forwards.3">6.1</a>, <a href="#rfc.iref.h.6"><b>6.1.1</b></a>, <a href="#rfc.xref.header.max-forwards.4">10.3.2</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li>
     5104                        <li>MIME-Version&nbsp;&nbsp;<a href="#rfc.xref.mime-version.1">10.3.2</a>, <a href="#rfc.iref.h.20"><b>A.1</b></a></li>
     5105                        <li>Referer&nbsp;&nbsp;<a href="#rfc.xref.header.referer.1">6.5</a>, <a href="#rfc.iref.h.13"><b>6.5.2</b></a>, <a href="#rfc.xref.header.referer.2">10.3.2</a>, <a href="#rfc.xref.header.referer.3">C</a></li>
     5106                        <li>Retry-After&nbsp;&nbsp;<a href="#rfc.xref.header.retry-after.1">7.6.4</a>, <a href="#rfc.xref.header.retry-after.2">8.1</a>, <a href="#rfc.iref.h.16"><b>8.1.2</b></a>, <a href="#rfc.xref.header.retry-after.3">10.3.2</a></li>
     5107                        <li>Server&nbsp;&nbsp;<a href="#rfc.xref.header.server.1">8.4</a>, <a href="#rfc.iref.h.19"><b>8.4.2</b></a>, <a href="#rfc.xref.header.server.2">10.3.2</a>, <a href="#rfc.xref.header.server.3">11.1</a>, <a href="#rfc.xref.header.server.4">C</a></li>
     5108                        <li>User-Agent&nbsp;&nbsp;<a href="#rfc.xref.header.user-agent.1">3.5.1</a>, <a href="#rfc.xref.header.user-agent.2">6.5</a>, <a href="#rfc.iref.h.14"><b>6.5.3</b></a>, <a href="#rfc.xref.header.user-agent.3">10.3.2</a>, <a href="#rfc.xref.header.user-agent.4">11.1</a></li>
    51035109                     </ul>
    51045110                  </li>
    … …  
    51105116            </li>
    51115117            <li><a id="rfc.index.L" href="#rfc.index.L"><b>L</b></a><ul>
    5112                   <li>Location header field&nbsp;&nbsp;<a href="#rfc.xref.header.location.1">5.3.3</a>, <a href="#rfc.xref.header.location.2">7.4</a>, <a href="#rfc.xref.header.location.3">8.1</a>, <a href="#rfc.iref.l.1"><b>10.13</b></a>, <a href="#rfc.xref.header.location.4">11.3.2</a>, <a href="#rfc.xref.header.location.5">C</a></li>
     5118                  <li>Location header field&nbsp;&nbsp;<a href="#rfc.xref.header.location.1">5.3.3</a>, <a href="#rfc.xref.header.location.2">7.4</a>, <a href="#rfc.xref.header.location.3">8.1</a>, <a href="#rfc.iref.l.1"><b>8.1.1</b></a>, <a href="#rfc.xref.header.location.4">10.3.2</a>, <a href="#rfc.xref.header.location.5">C</a></li>
    51135119               </ul>
    51145120            </li>
    51155121            <li><a id="rfc.index.M" href="#rfc.index.M"><b>M</b></a><ul>
    5116                   <li>Max-Forwards header field&nbsp;&nbsp;<a href="#rfc.xref.header.max-forwards.1">5.3.7</a>, <a href="#rfc.xref.header.max-forwards.2">5.3.8</a>, <a href="#rfc.xref.header.max-forwards.3">6.1</a>, <a href="#rfc.iref.m.9"><b>10.14</b></a>, <a href="#rfc.xref.header.max-forwards.4">11.3.2</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li>
     5122                  <li>Max-Forwards header field&nbsp;&nbsp;<a href="#rfc.xref.header.max-forwards.1">5.3.7</a>, <a href="#rfc.xref.header.max-forwards.2">5.3.8</a>, <a href="#rfc.xref.header.max-forwards.3">6.1</a>, <a href="#rfc.iref.m.9"><b>6.1.1</b></a>, <a href="#rfc.xref.header.max-forwards.4">10.3.2</a>, <a href="#rfc.xref.header.max-forwards.5">C</a></li>
    51175123                  <li>Methods&nbsp;&nbsp;
    51185124                     <ul>
    5119                         <li>CONNECT&nbsp;&nbsp;<a href="#rfc.xref.CONNECT.1">5.1</a>, <a href="#rfc.iref.m.6"><b>5.3.6</b></a>, <a href="#rfc.xref.CONNECT.2">11.1.3</a>, <a href="#rfc.xref.CONNECT.3">C</a></li>
    5120                         <li>DELETE&nbsp;&nbsp;<a href="#rfc.xref.DELETE.1">5.1</a>, <a href="#rfc.iref.m.5"><b>5.3.5</b></a>, <a href="#rfc.xref.DELETE.2">11.1.3</a></li>
    5121                         <li>GET&nbsp;&nbsp;<a href="#rfc.xref.GET.1">5.1</a>, <a href="#rfc.iref.m.1"><b>5.3.1</b></a>, <a href="#rfc.xref.GET.2">11.1.3</a></li>
    5122                         <li>HEAD&nbsp;&nbsp;<a href="#rfc.xref.HEAD.1">5.1</a>, <a href="#rfc.iref.m.2"><b>5.3.2</b></a>, <a href="#rfc.xref.HEAD.2">11.1.3</a></li>
    5123                         <li>OPTIONS&nbsp;&nbsp;<a href="#rfc.xref.OPTIONS.1">5.1</a>, <a href="#rfc.iref.m.7"><b>5.3.7</b></a>, <a href="#rfc.xref.OPTIONS.2">10.14</a>, <a href="#rfc.xref.OPTIONS.3">11.1.3</a></li>
    5124                         <li>POST&nbsp;&nbsp;<a href="#rfc.xref.POST.1">5.1</a>, <a href="#rfc.iref.m.3"><b>5.3.3</b></a>, <a href="#rfc.xref.POST.2">11.1.3</a>, <a href="#rfc.xref.POST.3">C</a></li>
    5125                         <li>PUT&nbsp;&nbsp;<a href="#rfc.xref.PUT.1">5.1</a>, <a href="#rfc.iref.m.4"><b>5.3.4</b></a>, <a href="#rfc.xref.PUT.2">11.1.3</a>, <a href="#rfc.xref.PUT.3">C</a></li>
    5126                         <li>TRACE&nbsp;&nbsp;<a href="#rfc.xref.TRACE.1">5.1</a>, <a href="#rfc.iref.m.8"><b>5.3.8</b></a>, <a href="#rfc.xref.TRACE.2">10.14</a>, <a href="#rfc.xref.TRACE.3">11.1.3</a>, <a href="#rfc.xref.TRACE.4">12.1</a></li>
     5125                        <li>CONNECT&nbsp;&nbsp;<a href="#rfc.xref.CONNECT.1">5.1</a>, <a href="#rfc.iref.m.6"><b>5.3.6</b></a>, <a href="#rfc.xref.CONNECT.2">10.1.3</a>, <a href="#rfc.xref.CONNECT.3">C</a></li>
     5126                        <li>DELETE&nbsp;&nbsp;<a href="#rfc.xref.DELETE.1">5.1</a>, <a href="#rfc.iref.m.5"><b>5.3.5</b></a>, <a href="#rfc.xref.DELETE.2">10.1.3</a></li>
     5127                        <li>GET&nbsp;&nbsp;<a href="#rfc.xref.GET.1">5.1</a>, <a href="#rfc.iref.m.1"><b>5.3.1</b></a>, <a href="#rfc.xref.GET.2">10.1.3</a></li>
     5128                        <li>HEAD&nbsp;&nbsp;<a href="#rfc.xref.HEAD.1">5.1</a>, <a href="#rfc.iref.m.2"><b>5.3.2</b></a>, <a href="#rfc.xref.HEAD.2">10.1.3</a></li>
     5129                        <li>OPTIONS&nbsp;&nbsp;<a href="#rfc.xref.OPTIONS.1">5.1</a>, <a href="#rfc.iref.m.7"><b>5.3.7</b></a>, <a href="#rfc.xref.OPTIONS.2">6.1.1</a>, <a href="#rfc.xref.OPTIONS.3">10.1.3</a></li>
     5130                        <li>POST&nbsp;&nbsp;<a href="#rfc.xref.POST.1">5.1</a>, <a href="#rfc.iref.m.3"><b>5.3.3</b></a>, <a href="#rfc.xref.POST.2">10.1.3</a>, <a href="#rfc.xref.POST.3">C</a></li>
     5131                        <li>PUT&nbsp;&nbsp;<a href="#rfc.xref.PUT.1">5.1</a>, <a href="#rfc.iref.m.4"><b>5.3.4</b></a>, <a href="#rfc.xref.PUT.2">10.1.3</a>, <a href="#rfc.xref.PUT.3">C</a></li>
     5132                        <li>TRACE&nbsp;&nbsp;<a href="#rfc.xref.TRACE.1">5.1</a>, <a href="#rfc.iref.m.8"><b>5.3.8</b></a>, <a href="#rfc.xref.TRACE.2">6.1.1</a>, <a href="#rfc.xref.TRACE.3">10.1.3</a>, <a href="#rfc.xref.TRACE.4">11.1</a></li>
    51275133                     </ul>
    51285134                  </li>
    5129                   <li>MIME-Version header field&nbsp;&nbsp;<a href="#rfc.xref.mime-version.1">11.3.2</a>, <a href="#rfc.iref.m.10"><b>A.1</b></a></li>
     5135                  <li>MIME-Version header field&nbsp;&nbsp;<a href="#rfc.xref.mime-version.1">10.3.2</a>, <a href="#rfc.iref.m.10"><b>A.1</b></a></li>
    51305136               </ul>
    51315137            </li>
    51325138            <li><a id="rfc.index.O" href="#rfc.index.O"><b>O</b></a><ul>
    5133                   <li>OPTIONS method&nbsp;&nbsp;<a href="#rfc.xref.OPTIONS.1">5.1</a>, <a href="#rfc.iref.o.1"><b>5.3.7</b></a>, <a href="#rfc.xref.OPTIONS.2">10.14</a>, <a href="#rfc.xref.OPTIONS.3">11.1.3</a></li>
     5139                  <li>OPTIONS method&nbsp;&nbsp;<a href="#rfc.xref.OPTIONS.1">5.1</a>, <a href="#rfc.iref.o.1"><b>5.3.7</b></a>, <a href="#rfc.xref.OPTIONS.2">6.1.1</a>, <a href="#rfc.xref.OPTIONS.3">10.1.3</a></li>
    51345140               </ul>
    51355141            </li>
    51365142            <li><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul>
    5137                   <li><em>Part1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.1">1</a>, <a href="#rfc.xref.Part1.2">1.1</a>, <a href="#rfc.xref.Part1.3">1.2</a>, <a href="#rfc.xref.Part1.4">2</a>, <a href="#rfc.xref.Part1.5">2</a>, <a href="#rfc.xref.Part1.6">2</a>, <a href="#rfc.xref.Part1.7">3</a>, <a href="#rfc.xref.Part1.8">3.1</a>, <a href="#rfc.xref.Part1.9">4.1</a>, <a href="#rfc.xref.Part1.10">4.2</a>, <a href="#rfc.xref.Part1.11">5.3.6</a>, <a href="#rfc.xref.Part1.12">5.3.7</a>, <a href="#rfc.xref.Part1.13">5.3.8</a>, <a href="#rfc.xref.Part1.14">5.3.8</a>, <a href="#rfc.xref.Part1.15">6.1</a>, <a href="#rfc.xref.Part1.16">6.5</a>, <a href="#rfc.xref.Part1.17">7.2.1</a>, <a href="#rfc.xref.Part1.18">7.2.2</a>, <a href="#rfc.xref.Part1.19">7.3.4</a>, <a href="#rfc.xref.Part1.20">7.3.6</a>, <a href="#rfc.xref.Part1.21">7.5.15</a>, <a href="#rfc.xref.Part1.22">7.6.6</a>, <a href="#rfc.xref.Part1.23">8</a>, <a href="#rfc.xref.Part1.24">9.4</a>, <a href="#rfc.xref.Part1.25">9.4</a>, <a href="#rfc.xref.Part1.26">9.4</a>, <a href="#rfc.xref.Part1.27">10.8</a>, <a href="#rfc.xref.Part1.28">10.11</a>, <a href="#rfc.xref.Part1.29">10.17</a>, <a href="#rfc.xref.Part1.30">10.17</a>, <a href="#rfc.xref.Part1.31">10.18</a>, <a href="#rfc.xref.Part1.32">11.1.2</a>, <a href="#rfc.xref.Part1.33">11.3.1</a>, <a href="#rfc.xref.Part1.34">11.3.1</a>, <a href="#rfc.xref.Part1.35">11.3.1</a>, <a href="#rfc.xref.Part1.36">11.3.1</a>, <a href="#rfc.xref.Part1.37">11.3.1</a>, <a href="#rfc.xref.Part1.38">11.3.1</a>, <a href="#rfc.xref.Part1.39">11.4</a>, <a href="#rfc.xref.Part1.40">11.4.1</a>, <a href="#rfc.xref.Part1.41">11.4.1</a>, <a href="#rfc.xref.Part1.42">11.4.2</a>, <a href="#rfc.xref.Part1.43">11.4.2</a>, <a href="#rfc.xref.Part1.44">11.4.2</a>, <a href="#rfc.xref.Part1.45">13</a>, <a href="#Part1"><b>14.1</b></a>, <a href="#rfc.xref.Part1.46">C</a>, <a href="#rfc.xref.Part1.47">D</a>, <a href="#rfc.xref.Part1.48">D</a>, <a href="#rfc.xref.Part1.49">D</a>, <a href="#rfc.xref.Part1.50">D</a>, <a href="#rfc.xref.Part1.51">D</a>, <a href="#rfc.xref.Part1.52">D</a>, <a href="#rfc.xref.Part1.53">D</a>, <a href="#rfc.xref.Part1.54">D</a>, <a href="#rfc.xref.Part1.55">D</a>, <a href="#rfc.xref.Part1.56">D</a>, <a href="#rfc.xref.Part1.57">D</a><ul>
     5143                  <li><em>Part1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.1">1</a>, <a href="#rfc.xref.Part1.2">1.1</a>, <a href="#rfc.xref.Part1.3">1.2</a>, <a href="#rfc.xref.Part1.4">2</a>, <a href="#rfc.xref.Part1.5">2</a>, <a href="#rfc.xref.Part1.6">2</a>, <a href="#rfc.xref.Part1.7">3</a>, <a href="#rfc.xref.Part1.8">3.1</a>, <a href="#rfc.xref.Part1.9">3.2.4</a>, <a href="#rfc.xref.Part1.10">4.1</a>, <a href="#rfc.xref.Part1.11">4.2</a>, <a href="#rfc.xref.Part1.12">5.3.6</a>, <a href="#rfc.xref.Part1.13">5.3.7</a>, <a href="#rfc.xref.Part1.14">5.3.8</a>, <a href="#rfc.xref.Part1.15">5.3.8</a>, <a href="#rfc.xref.Part1.16">6.1</a>, <a href="#rfc.xref.Part1.17">6.1.2</a>, <a href="#rfc.xref.Part1.18">6.5</a>, <a href="#rfc.xref.Part1.19">6.5.3</a>, <a href="#rfc.xref.Part1.20">7.2.1</a>, <a href="#rfc.xref.Part1.21">7.2.2</a>, <a href="#rfc.xref.Part1.22">7.3.4</a>, <a href="#rfc.xref.Part1.23">7.3.6</a>, <a href="#rfc.xref.Part1.24">7.5.15</a>, <a href="#rfc.xref.Part1.25">7.6.6</a>, <a href="#rfc.xref.Part1.26">8</a>, <a href="#rfc.xref.Part1.27">8.4.2</a>, <a href="#rfc.xref.Part1.28">8.4.2</a>, <a href="#rfc.xref.Part1.29">9.4</a>, <a href="#rfc.xref.Part1.30">9.4</a>, <a href="#rfc.xref.Part1.31">9.4</a>, <a href="#rfc.xref.Part1.32">10.1.2</a>, <a href="#rfc.xref.Part1.33">10.3.1</a>, <a href="#rfc.xref.Part1.34">10.3.1</a>, <a href="#rfc.xref.Part1.35">10.3.1</a>, <a href="#rfc.xref.Part1.36">10.3.1</a>, <a href="#rfc.xref.Part1.37">10.3.1</a>, <a href="#rfc.xref.Part1.38">10.3.1</a>, <a href="#rfc.xref.Part1.39">10.4</a>, <a href="#rfc.xref.Part1.40">10.4.1</a>, <a href="#rfc.xref.Part1.41">10.4.1</a>, <a href="#rfc.xref.Part1.42">10.4.2</a>, <a href="#rfc.xref.Part1.43">10.4.2</a>, <a href="#rfc.xref.Part1.44">10.4.2</a>, <a href="#rfc.xref.Part1.45">12</a>, <a href="#Part1"><b>13.1</b></a>, <a href="#rfc.xref.Part1.46">C</a>, <a href="#rfc.xref.Part1.47">D</a>, <a href="#rfc.xref.Part1.48">D</a>, <a href="#rfc.xref.Part1.49">D</a>, <a href="#rfc.xref.Part1.50">D</a>, <a href="#rfc.xref.Part1.51">D</a>, <a href="#rfc.xref.Part1.52">D</a>, <a href="#rfc.xref.Part1.53">D</a>, <a href="#rfc.xref.Part1.54">D</a>, <a href="#rfc.xref.Part1.55">D</a>, <a href="#rfc.xref.Part1.56">D</a>, <a href="#rfc.xref.Part1.57">D</a><ul>
    51385144                        <li><em>Section 1.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.3">1.2</a></li>
    5139                         <li><em>Section 2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.19">7.3.4</a></li>
     5145                        <li><em>Section 2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.22">7.3.4</a></li>
    51405146                        <li><em>Section 2.5</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.2">1.1</a></li>
    5141                         <li><em>Section 2.6</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.22">7.6.6</a></li>
     5147                        <li><em>Section 2.6</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.25">7.6.6</a></li>
    51425148                        <li><em>Section 2.7</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.4">2</a>, <a href="#rfc.xref.Part1.54">D</a>, <a href="#rfc.xref.Part1.56">D</a>, <a href="#rfc.xref.Part1.57">D</a></li>
    5143                         <li><em>Section 3.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.29">10.17</a>, <a href="#rfc.xref.Part1.31">10.18</a>, <a href="#rfc.xref.Part1.33">11.3.1</a>, <a href="#rfc.xref.Part1.36">11.3.1</a></li>
     5149                        <li><em>Section 3.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.19">6.5.3</a>, <a href="#rfc.xref.Part1.27">8.4.2</a>, <a href="#rfc.xref.Part1.33">10.3.1</a>, <a href="#rfc.xref.Part1.36">10.3.1</a></li>
    51445150                        <li><em>Section 3.2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.48">D</a>, <a href="#rfc.xref.Part1.49">D</a>, <a href="#rfc.xref.Part1.50">D</a></li>
    5145                         <li><em>Section 3.2.4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.35">11.3.1</a>, <a href="#rfc.xref.Part1.51">D</a>, <a href="#rfc.xref.Part1.52">D</a>, <a href="#rfc.xref.Part1.53">D</a>, <a href="#rfc.xref.Part1.55">D</a></li>
    5146                         <li><em>Section 3.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.7">3</a>, <a href="#rfc.xref.Part1.10">4.2</a>, <a href="#rfc.xref.Part1.20">7.3.6</a>, <a href="#rfc.xref.Part1.32">11.1.2</a></li>
    5147                         <li><em>Section 3.3.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.9">4.1</a></li>
    5148                         <li><em>Section 4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.40">11.4.1</a></li>
    5149                         <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.38">11.3.1</a></li>
    5150                         <li><em>Section 4.2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.24">9.4</a>, <a href="#rfc.xref.Part1.42">11.4.2</a></li>
    5151                         <li><em>Section 4.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.39">11.4</a>, <a href="#rfc.xref.Part1.41">11.4.1</a></li>
    5152                         <li><em>Section 4.2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.25">9.4</a>, <a href="#rfc.xref.Part1.43">11.4.2</a></li>
    5153                         <li><em>Section 4.2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.26">9.4</a>, <a href="#rfc.xref.Part1.44">11.4.2</a></li>
    5154                         <li><em>Section 4.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.16">6.5</a></li>
    5155                         <li><em>Section 5.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.5">2</a>, <a href="#rfc.xref.Part1.11">5.3.6</a>, <a href="#rfc.xref.Part1.12">5.3.7</a></li>
    5156                         <li><em>Section 5.4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.15">6.1</a></li>
    5157                         <li><em>Section 5.5</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.6">2</a>, <a href="#rfc.xref.Part1.8">3.1</a>, <a href="#rfc.xref.Part1.23">8</a>, <a href="#rfc.xref.Part1.27">10.8</a></li>
    5158                         <li><em>Section 5.7</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.13">5.3.8</a>, <a href="#rfc.xref.Part1.30">10.17</a>, <a href="#rfc.xref.Part1.46">C</a></li>
    5159                         <li><em>Section 6.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.37">11.3.1</a></li>
    5160                         <li><em>Section 6.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.17">7.2.1</a>, <a href="#rfc.xref.Part1.28">10.11</a></li>
    5161                         <li><em>Section 6.4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.18">7.2.2</a>, <a href="#rfc.xref.Part1.21">7.5.15</a></li>
    5162                         <li><em>Section 7.3.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.14">5.3.8</a></li>
    5163                         <li><em>Section 9</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.45">13</a></li>
    5164                         <li><em>Appendix B</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.34">11.3.1</a></li>
     5151                        <li><em>Section 3.2.4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.35">10.3.1</a>, <a href="#rfc.xref.Part1.51">D</a>, <a href="#rfc.xref.Part1.52">D</a>, <a href="#rfc.xref.Part1.53">D</a>, <a href="#rfc.xref.Part1.55">D</a></li>
     5152                        <li><em>Section 3.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.7">3</a>, <a href="#rfc.xref.Part1.11">4.2</a>, <a href="#rfc.xref.Part1.23">7.3.6</a>, <a href="#rfc.xref.Part1.32">10.1.2</a></li>
     5153                        <li><em>Section 3.3.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.10">4.1</a></li>
     5154                        <li><em>Section 4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.40">10.4.1</a></li>
     5155                        <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.38">10.3.1</a></li>
     5156                        <li><em>Section 4.2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.29">9.4</a>, <a href="#rfc.xref.Part1.42">10.4.2</a></li>
     5157                        <li><em>Section 4.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.39">10.4</a>, <a href="#rfc.xref.Part1.41">10.4.1</a></li>
     5158                        <li><em>Section 4.2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.30">9.4</a>, <a href="#rfc.xref.Part1.43">10.4.2</a></li>
     5159                        <li><em>Section 4.2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.31">9.4</a>, <a href="#rfc.xref.Part1.44">10.4.2</a></li>
     5160                        <li><em>Section 4.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.18">6.5</a></li>
     5161                        <li><em>Section 5.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.5">2</a>, <a href="#rfc.xref.Part1.12">5.3.6</a>, <a href="#rfc.xref.Part1.13">5.3.7</a></li>
     5162                        <li><em>Section 5.4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.16">6.1</a></li>
     5163                        <li><em>Section 5.5</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.6">2</a>, <a href="#rfc.xref.Part1.8">3.1</a>, <a href="#rfc.xref.Part1.9">3.2.4</a>, <a href="#rfc.xref.Part1.26">8</a></li>
     5164                        <li><em>Section 5.7</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.14">5.3.8</a>, <a href="#rfc.xref.Part1.28">8.4.2</a>, <a href="#rfc.xref.Part1.46">C</a></li>
     5165                        <li><em>Section 6.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.37">10.3.1</a></li>
     5166                        <li><em>Section 6.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.17">6.1.2</a>, <a href="#rfc.xref.Part1.20">7.2.1</a></li>
     5167                        <li><em>Section 6.4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.21">7.2.2</a>, <a href="#rfc.xref.Part1.24">7.5.15</a></li>
     5168                        <li><em>Section 7.3.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.15">5.3.8</a></li>
     5169                        <li><em>Section 9</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.45">12</a></li>
     5170                        <li><em>Appendix B</em>&nbsp;&nbsp;<a href="#rfc.xref.Part1.34">10.3.1</a></li>
    51655171                     </ul>
    51665172                  </li>
    5167                   <li><em>Part4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.1">3.2</a>, <a href="#rfc.xref.Part4.2">3.2</a>, <a href="#rfc.xref.Part4.3">5.3.1</a>, <a href="#rfc.xref.Part4.4">6.2</a>, <a href="#rfc.xref.Part4.5">6.2</a>, <a href="#rfc.xref.Part4.6">6.2</a>, <a href="#rfc.xref.Part4.7">6.2</a>, <a href="#rfc.xref.Part4.8">6.2</a>, <a href="#rfc.xref.Part4.9">7.1</a>, <a href="#rfc.xref.Part4.10">7.1</a>, <a href="#rfc.xref.Part4.11">7.1</a>, <a href="#rfc.xref.Part4.12">7.3.2</a>, <a href="#rfc.xref.Part4.13">7.4</a>, <a href="#Part4"><b>14.1</b></a>, <a href="#rfc.xref.Part4.14">F.2</a><ul>
    5168                         <li><em>Section 2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.2">3.2</a></li>
    5169                         <li><em>Section 2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.1">3.2</a>, <a href="#rfc.xref.Part4.12">7.3.2</a></li>
     5173                  <li><em>Part4</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.1">3.3</a>, <a href="#rfc.xref.Part4.2">3.3</a>, <a href="#rfc.xref.Part4.3">5.3.1</a>, <a href="#rfc.xref.Part4.4">6.2</a>, <a href="#rfc.xref.Part4.5">6.2</a>, <a href="#rfc.xref.Part4.6">6.2</a>, <a href="#rfc.xref.Part4.7">6.2</a>, <a href="#rfc.xref.Part4.8">6.2</a>, <a href="#rfc.xref.Part4.9">7.1</a>, <a href="#rfc.xref.Part4.10">7.1</a>, <a href="#rfc.xref.Part4.11">7.1</a>, <a href="#rfc.xref.Part4.12">7.3.2</a>, <a href="#rfc.xref.Part4.13">7.4</a>, <a href="#Part4"><b>13.1</b></a>, <a href="#rfc.xref.Part4.14">F.2</a><ul>
     5174                        <li><em>Section 2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.2">3.3</a></li>
     5175                        <li><em>Section 2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.1">3.3</a>, <a href="#rfc.xref.Part4.12">7.3.2</a></li>
    51705176                        <li><em>Section 3.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.5">6.2</a></li>
    51715177                        <li><em>Section 3.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part4.6">6.2</a></li>
    … …  
    51775183                     </ul>
    51785184                  </li>
    5179                   <li><em>Part5</em>&nbsp;&nbsp;<a href="#rfc.xref.Part5.1">4.1</a>, <a href="#rfc.xref.Part5.2">5.3.1</a>, <a href="#rfc.xref.Part5.3">5.3.1</a>, <a href="#rfc.xref.Part5.4">5.3.4</a>, <a href="#rfc.xref.Part5.5">6.1</a>, <a href="#rfc.xref.Part5.6">6.2</a>, <a href="#rfc.xref.Part5.7">7.1</a>, <a href="#rfc.xref.Part5.8">7.1</a>, <a href="#rfc.xref.Part5.9">7.1</a>, <a href="#rfc.xref.Part5.10">8.4</a>, <a href="#Part5"><b>14.1</b></a><ul>
     5185                  <li><em>Part5</em>&nbsp;&nbsp;<a href="#rfc.xref.Part5.1">4.1</a>, <a href="#rfc.xref.Part5.2">5.3.1</a>, <a href="#rfc.xref.Part5.3">5.3.1</a>, <a href="#rfc.xref.Part5.4">5.3.4</a>, <a href="#rfc.xref.Part5.5">6.1</a>, <a href="#rfc.xref.Part5.6">6.2</a>, <a href="#rfc.xref.Part5.7">7.1</a>, <a href="#rfc.xref.Part5.8">7.1</a>, <a href="#rfc.xref.Part5.9">7.1</a>, <a href="#rfc.xref.Part5.10">8.4</a>, <a href="#Part5"><b>13.1</b></a><ul>
    51805186                        <li><em>Section 3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part5.7">7.1</a></li>
    51815187                        <li><em>Section 3.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part5.8">7.1</a></li>
    … …  
    51875193                     </ul>
    51885194                  </li>
    5189                   <li><em>Part6</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.1">3.2</a>, <a href="#rfc.xref.Part6.2">3.4.1</a>, <a href="#rfc.xref.Part6.3">5.2.3</a>, <a href="#rfc.xref.Part6.4">5.3.1</a>, <a href="#rfc.xref.Part6.5">5.3.2</a>, <a href="#rfc.xref.Part6.6">5.3.3</a>, <a href="#rfc.xref.Part6.7">5.3.4</a>, <a href="#rfc.xref.Part6.8">5.3.5</a>, <a href="#rfc.xref.Part6.9">7.3.1</a>, <a href="#rfc.xref.Part6.10">7.3.4</a>, <a href="#rfc.xref.Part6.11">7.3.4</a>, <a href="#rfc.xref.Part6.12">7.3.4</a>, <a href="#rfc.xref.Part6.13">7.4.1</a>, <a href="#rfc.xref.Part6.14">7.4.2</a>, <a href="#rfc.xref.Part6.15">7.5.9</a>, <a href="#rfc.xref.Part6.16">8.2</a>, <a href="#rfc.xref.Part6.17">8.2</a>, <a href="#rfc.xref.Part6.18">11.2.2</a>, <a href="#rfc.xref.Part6.19">11.3.1</a>, <a href="#Part6"><b>14.1</b></a><ul>
     5195                  <li><em>Part6</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.1">3.2</a>, <a href="#rfc.xref.Part6.2">3.5.1</a>, <a href="#rfc.xref.Part6.3">5.2.3</a>, <a href="#rfc.xref.Part6.4">5.3.1</a>, <a href="#rfc.xref.Part6.5">5.3.2</a>, <a href="#rfc.xref.Part6.6">5.3.3</a>, <a href="#rfc.xref.Part6.7">5.3.4</a>, <a href="#rfc.xref.Part6.8">5.3.5</a>, <a href="#rfc.xref.Part6.9">7.3.1</a>, <a href="#rfc.xref.Part6.10">7.3.4</a>, <a href="#rfc.xref.Part6.11">7.3.4</a>, <a href="#rfc.xref.Part6.12">7.3.4</a>, <a href="#rfc.xref.Part6.13">7.4.1</a>, <a href="#rfc.xref.Part6.14">7.4.2</a>, <a href="#rfc.xref.Part6.15">7.5.9</a>, <a href="#rfc.xref.Part6.16">8.2</a>, <a href="#rfc.xref.Part6.17">8.2</a>, <a href="#rfc.xref.Part6.18">10.2.2</a>, <a href="#rfc.xref.Part6.19">10.3.1</a>, <a href="#Part6"><b>13.1</b></a><ul>
    51905196                        <li><em>Section 4.1.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.6">5.3.3</a></li>
    51915197                        <li><em>Section 4.1.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.9">7.3.1</a>, <a href="#rfc.xref.Part6.12">7.3.4</a>, <a href="#rfc.xref.Part6.13">7.4.1</a>, <a href="#rfc.xref.Part6.14">7.4.2</a>, <a href="#rfc.xref.Part6.15">7.5.9</a></li>
    … …  
    51955201                        <li><em>Section 7.2</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.10">7.3.4</a></li>
    51965202                        <li><em>Section 7.3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.1">3.2</a></li>
    5197                         <li><em>Section 7.5</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.2">3.4.1</a>, <a href="#rfc.xref.Part6.17">8.2</a></li>
     5203                        <li><em>Section 7.5</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.2">3.5.1</a>, <a href="#rfc.xref.Part6.17">8.2</a></li>
    51985204                        <li><em>Section 7.6</em>&nbsp;&nbsp;<a href="#rfc.xref.Part6.11">7.3.4</a></li>
    51995205                     </ul>
    52005206                  </li>
    5201                   <li><em>Part7</em>&nbsp;&nbsp;<a href="#rfc.xref.Part7.1">6.4</a>, <a href="#rfc.xref.Part7.2">6.4</a>, <a href="#rfc.xref.Part7.3">7.1</a>, <a href="#rfc.xref.Part7.4">7.1</a>, <a href="#rfc.xref.Part7.5">7.1</a>, <a href="#rfc.xref.Part7.6">8.3</a>, <a href="#rfc.xref.Part7.7">8.3</a>, <a href="#Part7"><b>14.1</b></a><ul>
     5207                  <li><em>Part7</em>&nbsp;&nbsp;<a href="#rfc.xref.Part7.1">6.4</a>, <a href="#rfc.xref.Part7.2">6.4</a>, <a href="#rfc.xref.Part7.3">7.1</a>, <a href="#rfc.xref.Part7.4">7.1</a>, <a href="#rfc.xref.Part7.5">7.1</a>, <a href="#rfc.xref.Part7.6">8.3</a>, <a href="#rfc.xref.Part7.7">8.3</a>, <a href="#Part7"><b>13.1</b></a><ul>
    52025208                        <li><em>Section 3</em>&nbsp;&nbsp;<a href="#rfc.xref.Part7.3">7.1</a></li>
    52035209                        <li><em>Section 3.1</em>&nbsp;&nbsp;<a href="#rfc.xref.Part7.4">7.1</a></li>
    … …  
    52105216                  </li>
    52115217                  <li>payload&nbsp;&nbsp;<a href="#rfc.iref.p.1">4</a></li>
    5212                   <li>POST method&nbsp;&nbsp;<a href="#rfc.xref.POST.1">5.1</a>, <a href="#rfc.iref.p.2"><b>5.3.3</b></a>, <a href="#rfc.xref.POST.2">11.1.3</a>, <a href="#rfc.xref.POST.3">C</a></li>
    5213                   <li>PUT method&nbsp;&nbsp;<a href="#rfc.xref.PUT.1">5.1</a>, <a href="#rfc.iref.p.3"><b>5.3.4</b></a>, <a href="#rfc.xref.PUT.2">11.1.3</a>, <a href="#rfc.xref.PUT.3">C</a></li>
     5218                  <li>POST method&nbsp;&nbsp;<a href="#rfc.xref.POST.1">5.1</a>, <a href="#rfc.iref.p.2"><b>5.3.3</b></a>, <a href="#rfc.xref.POST.2">10.1.3</a>, <a href="#rfc.xref.POST.3">C</a></li>
     5219                  <li>PUT method&nbsp;&nbsp;<a href="#rfc.xref.PUT.1">5.1</a>, <a href="#rfc.iref.p.3"><b>5.3.4</b></a>, <a href="#rfc.xref.PUT.2">10.1.3</a>, <a href="#rfc.xref.PUT.3">C</a></li>
    52145220               </ul>
    52155221            </li>
    52165222            <li><a id="rfc.index.R" href="#rfc.index.R"><b>R</b></a><ul>
    5217                   <li>Referer header field&nbsp;&nbsp;<a href="#rfc.xref.header.referer.1">6.5</a>, <a href="#rfc.iref.r.2"><b>10.15</b></a>, <a href="#rfc.xref.header.referer.2">11.3.2</a>, <a href="#rfc.xref.header.referer.3">C</a></li>
     5223                  <li>Referer header field&nbsp;&nbsp;<a href="#rfc.xref.header.referer.1">6.5</a>, <a href="#rfc.iref.r.2"><b>6.5.2</b></a>, <a href="#rfc.xref.header.referer.2">10.3.2</a>, <a href="#rfc.xref.header.referer.3">C</a></li>
    52185224                  <li>representation&nbsp;&nbsp;<a href="#rfc.iref.r.1">3</a></li>
    5219                   <li><em>REST</em>&nbsp;&nbsp;<a href="#rfc.xref.REST.1">5.1</a>, <a href="#REST"><b>14.2</b></a></li>
    5220                   <li>Retry-After header field&nbsp;&nbsp;<a href="#rfc.xref.header.retry-after.1">7.6.4</a>, <a href="#rfc.xref.header.retry-after.2">8.1</a>, <a href="#rfc.iref.r.3"><b>10.16</b></a>, <a href="#rfc.xref.header.retry-after.3">11.3.2</a></li>
    5221                   <li><em>RFC1123</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1123.1">9.1</a>, <a href="#rfc.xref.RFC1123.2">9.1</a>, <a href="#RFC1123"><b>14.2</b></a><ul>
     5225                  <li><em>REST</em>&nbsp;&nbsp;<a href="#rfc.xref.REST.1">5.1</a>, <a href="#REST"><b>13.2</b></a></li>
     5226                  <li>Retry-After header field&nbsp;&nbsp;<a href="#rfc.xref.header.retry-after.1">7.6.4</a>, <a href="#rfc.xref.header.retry-after.2">8.1</a>, <a href="#rfc.iref.r.3"><b>8.1.2</b></a>, <a href="#rfc.xref.header.retry-after.3">10.3.2</a></li>
     5227                  <li><em>RFC1123</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1123.1">9.1</a>, <a href="#rfc.xref.RFC1123.2">9.1</a>, <a href="#RFC1123"><b>13.2</b></a><ul>
    52225228                        <li><em>Section 5.2.14</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1123.2">9.1</a></li>
    52235229                     </ul>
    52245230                  </li>
    5225                   <li><em>RFC1945</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1945.1">7.4</a>, <a href="#RFC1945"><b>14.2</b></a>, <a href="#rfc.xref.RFC1945.2">B</a><ul>
     5231                  <li><em>RFC1945</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1945.1">7.4</a>, <a href="#RFC1945"><b>13.2</b></a>, <a href="#rfc.xref.RFC1945.2">B</a><ul>
    52265232                        <li><em>Section 9.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1945.1">7.4</a></li>
    52275233                     </ul>
    52285234                  </li>
    5229                   <li><em>RFC1950</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1950.1">11.4.2</a>, <a href="#RFC1950"><b>14.1</b></a></li>
    5230                   <li><em>RFC1951</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1951.1">11.4.2</a>, <a href="#RFC1951"><b>14.1</b></a></li>
    5231                   <li><em>RFC1952</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1952.1">11.4.2</a>, <a href="#RFC1952"><b>14.1</b></a></li>
    5232                   <li><em>RFC2045</em>&nbsp;&nbsp;<a href="#RFC2045"><b>14.1</b></a>, <a href="#rfc.xref.RFC2045.1">A</a>, <a href="#rfc.xref.RFC2045.2">A.1</a></li>
    5233                   <li><em>RFC2046</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2046.1">3.3</a>, <a href="#rfc.xref.RFC2046.2">9.5</a>, <a href="#rfc.xref.RFC2046.3">9.5.2</a>, <a href="#RFC2046"><b>14.1</b></a>, <a href="#rfc.xref.RFC2046.4">A.2</a><ul>
    5234                         <li><em>Section 4.5.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2046.1">3.3</a></li>
     5235                  <li><em>RFC1950</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1950.1">10.4.2</a>, <a href="#RFC1950"><b>13.1</b></a></li>
     5236                  <li><em>RFC1951</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1951.1">10.4.2</a>, <a href="#RFC1951"><b>13.1</b></a></li>
     5237                  <li><em>RFC1952</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC1952.1">10.4.2</a>, <a href="#RFC1952"><b>13.1</b></a></li>
     5238                  <li><em>RFC2045</em>&nbsp;&nbsp;<a href="#RFC2045"><b>13.1</b></a>, <a href="#rfc.xref.RFC2045.1">A</a>, <a href="#rfc.xref.RFC2045.2">A.1</a></li>
     5239                  <li><em>RFC2046</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2046.1">3.4</a>, <a href="#rfc.xref.RFC2046.2">9.5</a>, <a href="#rfc.xref.RFC2046.3">9.5.2</a>, <a href="#RFC2046"><b>13.1</b></a>, <a href="#rfc.xref.RFC2046.4">A.2</a><ul>
     5240                        <li><em>Section 4.5.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2046.1">3.4</a></li>
    52355241                        <li><em>Section 5.1.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2046.3">9.5.2</a></li>
    52365242                     </ul>
    52375243                  </li>
    5238                   <li><em>RFC2049</em>&nbsp;&nbsp;<a href="#RFC2049"><b>14.2</b></a>, <a href="#rfc.xref.RFC2049.1">A.2</a><ul>
     5244                  <li><em>RFC2049</em>&nbsp;&nbsp;<a href="#RFC2049"><b>13.2</b></a>, <a href="#rfc.xref.RFC2049.1">A.2</a><ul>
    52395245                        <li><em>Section 4</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2049.1">A.2</a></li>
    52405246                     </ul>
    52415247                  </li>
    5242                   <li><em>RFC2068</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2068.1">7.4</a>, <a href="#rfc.xref.RFC2068.2">7.4</a>, <a href="#RFC2068"><b>14.2</b></a>, <a href="#rfc.xref.RFC2068.3">B</a><ul>
     5248                  <li><em>RFC2068</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2068.1">7.4</a>, <a href="#rfc.xref.RFC2068.2">7.4</a>, <a href="#RFC2068"><b>13.2</b></a>, <a href="#rfc.xref.RFC2068.3">B</a><ul>
    52435249                        <li><em>Section 10.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2068.2">7.4</a></li>
    52445250                        <li><em>Section 10.3.4</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2068.1">7.4</a></li>
    52455251                     </ul>
    52465252                  </li>
    5247                   <li><em>RFC2076</em>&nbsp;&nbsp;<a href="#RFC2076"><b>14.2</b></a>, <a href="#rfc.xref.RFC2076.1">B</a></li>
    5248                   <li><em>RFC2119</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2119.1">1.1</a>, <a href="#RFC2119"><b>14.1</b></a></li>
    5249                   <li><em>RFC2277</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2277.1">9.3</a>, <a href="#RFC2277"><b>14.2</b></a></li>
    5250                   <li><em>RFC2295</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2295.1">3.4</a>, <a href="#RFC2295"><b>14.2</b></a></li>
    5251                   <li><em>RFC2388</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2388.1">9.5.2</a>, <a href="#RFC2388"><b>14.2</b></a></li>
    5252                   <li><em>RFC2557</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2557.1">10.8</a>, <a href="#RFC2557"><b>14.2</b></a>, <a href="#rfc.xref.RFC2557.2">A.6</a><ul>
    5253                         <li><em>Section 4</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2557.1">10.8</a></li>
     5253                  <li><em>RFC2076</em>&nbsp;&nbsp;<a href="#RFC2076"><b>13.2</b></a>, <a href="#rfc.xref.RFC2076.1">B</a></li>
     5254                  <li><em>RFC2119</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2119.1">1.1</a>, <a href="#RFC2119"><b>13.1</b></a></li>
     5255                  <li><em>RFC2277</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2277.1">9.3</a>, <a href="#RFC2277"><b>13.2</b></a></li>
     5256                  <li><em>RFC2295</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2295.1">3.5</a>, <a href="#RFC2295"><b>13.2</b></a></li>
     5257                  <li><em>RFC2388</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2388.1">9.5.2</a>, <a href="#RFC2388"><b>13.2</b></a></li>
     5258                  <li><em>RFC2557</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2557.1">3.2.4</a>, <a href="#RFC2557"><b>13.2</b></a>, <a href="#rfc.xref.RFC2557.2">A.6</a><ul>
     5259                        <li><em>Section 4</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2557.1">3.2.4</a></li>
    52545260                     </ul>
    52555261                  </li>
    5256                   <li><em>RFC2616</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.1">7.4</a>, <a href="#rfc.xref.RFC2616.2">10.4</a>, <a href="#RFC2616"><b>14.2</b></a>, <a href="#rfc.xref.RFC2616.3">F.1</a><ul>
    5257                         <li><em>Section 10.3.8</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.1">7.4</a></li>
    5258                         <li><em>Section 14.4</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.2">10.4</a></li>
     5262                  <li><em>RFC2616</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.1">6.3.5</a>, <a href="#rfc.xref.RFC2616.2">7.4</a>, <a href="#RFC2616"><b>13.2</b></a>, <a href="#rfc.xref.RFC2616.3">F.1</a><ul>
     5263                        <li><em>Section 10.3.8</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.2">7.4</a></li>
     5264                        <li><em>Section 14.4</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.1">6.3.5</a></li>
    52595265                     </ul>
    52605266                  </li>
    5261                   <li><em>RFC2817</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2817.1">11.2</a>, <a href="#RFC2817"><b>14.2</b></a>, <a href="#rfc.xref.RFC2817.2">C</a>, <a href="#rfc.xref.RFC2817.3">C</a>, <a href="#rfc.xref.RFC2817.4">C</a><ul>
    5262                         <li><em>Section 7.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2817.1">11.2</a>, <a href="#rfc.xref.RFC2817.3">C</a></li>
     5267                  <li><em>RFC2817</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2817.1">10.2</a>, <a href="#RFC2817"><b>13.2</b></a>, <a href="#rfc.xref.RFC2817.2">C</a>, <a href="#rfc.xref.RFC2817.3">C</a>, <a href="#rfc.xref.RFC2817.4">C</a><ul>
     5268                        <li><em>Section 7.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2817.1">10.2</a>, <a href="#rfc.xref.RFC2817.3">C</a></li>
    52635269                     </ul>
    52645270                  </li>
    5265                   <li><em>RFC3629</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3629.1">9.3</a>, <a href="#RFC3629"><b>14.2</b></a></li>
    5266                   <li><em>RFC3864</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3864.1">11.3</a>, <a href="#rfc.xref.RFC3864.2">11.3.1</a>, <a href="#RFC3864"><b>14.2</b></a><ul>
    5267                         <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3864.2">11.3.1</a></li>
     5271                  <li><em>RFC3629</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3629.1">9.3</a>, <a href="#RFC3629"><b>13.2</b></a></li>
     5272                  <li><em>RFC3864</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3864.1">10.3</a>, <a href="#rfc.xref.RFC3864.2">10.3.1</a>, <a href="#RFC3864"><b>13.2</b></a><ul>
     5273                        <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3864.2">10.3.1</a></li>
    52685274                     </ul>
    52695275                  </li>
    5270                   <li><em>RFC3986</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3986.1">10.13</a>, <a href="#rfc.xref.RFC3986.2">10.13</a>, <a href="#RFC3986"><b>14.1</b></a><ul>
    5271                         <li><em>Section 4.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3986.1">10.13</a></li>
    5272                         <li><em>Section 5</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3986.2">10.13</a></li>
     5276                  <li><em>RFC3986</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3986.1">8.1.1</a>, <a href="#rfc.xref.RFC3986.2">8.1.1</a>, <a href="#RFC3986"><b>13.1</b></a><ul>
     5277                        <li><em>Section 4.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3986.1">8.1.1</a></li>
     5278                        <li><em>Section 5</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3986.2">8.1.1</a></li>
    52735279                     </ul>
    52745280                  </li>
    5275                   <li><em>RFC4288</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4288.1">9.5</a>, <a href="#RFC4288"><b>14.2</b></a></li>
    5276                   <li><em>RFC4647</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.1">10.4</a>, <a href="#rfc.xref.RFC4647.2">10.4</a>, <a href="#rfc.xref.RFC4647.3">10.4</a>, <a href="#rfc.xref.RFC4647.4">10.4</a>, <a href="#RFC4647"><b>14.1</b></a><ul>
    5277                         <li><em>Section 2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.1">10.4</a></li>
    5278                         <li><em>Section 2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.2">10.4</a></li>
    5279                         <li><em>Section 3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.3">10.4</a></li>
    5280                         <li><em>Section 3.3.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.4">10.4</a></li>
     5281                  <li><em>RFC4288</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4288.1">9.5</a>, <a href="#RFC4288"><b>13.2</b></a></li>
     5282                  <li><em>RFC4647</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.1">6.3.5</a>, <a href="#rfc.xref.RFC4647.2">6.3.5</a>, <a href="#rfc.xref.RFC4647.3">6.3.5</a>, <a href="#rfc.xref.RFC4647.4">6.3.5</a>, <a href="#RFC4647"><b>13.1</b></a><ul>
     5283                        <li><em>Section 2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.1">6.3.5</a></li>
     5284                        <li><em>Section 2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.2">6.3.5</a></li>
     5285                        <li><em>Section 3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.3">6.3.5</a></li>
     5286                        <li><em>Section 3.3.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC4647.4">6.3.5</a></li>
    52815287                     </ul>
    52825288                  </li>
    5283                   <li><em>RFC5226</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5226.1">11.1.1</a>, <a href="#rfc.xref.RFC5226.2">11.2.1</a>, <a href="#rfc.xref.RFC5226.3">11.4.1</a>, <a href="#RFC5226"><b>14.2</b></a><ul>
    5284                         <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5226.1">11.1.1</a>, <a href="#rfc.xref.RFC5226.2">11.2.1</a>, <a href="#rfc.xref.RFC5226.3">11.4.1</a></li>
     5289                  <li><em>RFC5226</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5226.1">10.1.1</a>, <a href="#rfc.xref.RFC5226.2">10.2.1</a>, <a href="#rfc.xref.RFC5226.3">10.4.1</a>, <a href="#RFC5226"><b>13.2</b></a><ul>
     5290                        <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5226.1">10.1.1</a>, <a href="#rfc.xref.RFC5226.2">10.2.1</a>, <a href="#rfc.xref.RFC5226.3">10.4.1</a></li>
    52855291                     </ul>
    52865292                  </li>
    5287                   <li><em>RFC5234</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5234.1">1.2</a>, <a href="#rfc.xref.RFC5234.2">11.3.1</a>, <a href="#RFC5234"><b>14.1</b></a>, <a href="#rfc.xref.RFC5234.3">D</a><ul>
     5293                  <li><em>RFC5234</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5234.1">1.2</a>, <a href="#rfc.xref.RFC5234.2">10.3.1</a>, <a href="#RFC5234"><b>13.1</b></a>, <a href="#rfc.xref.RFC5234.3">D</a><ul>
    52885294                        <li><em>Appendix B.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5234.3">D</a></li>
    52895295                     </ul>
    52905296                  </li>
    5291                   <li><em>RFC5322</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5322.1">9.1</a>, <a href="#rfc.xref.RFC5322.2">10.10</a>, <a href="#rfc.xref.RFC5322.3">10.12</a>, <a href="#rfc.xref.RFC5322.4">10.12</a>, <a href="#RFC5322"><b>14.2</b></a>, <a href="#rfc.xref.RFC5322.5">A</a><ul>
    5292                         <li><em>Section 3.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5322.1">9.1</a></li>
    5293                         <li><em>Section 3.4</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5322.3">10.12</a>, <a href="#rfc.xref.RFC5322.4">10.12</a></li>
    5294                         <li><em>Section 3.6.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5322.2">10.10</a></li>
     5297                  <li><em>RFC5322</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5322.1">6.5.1</a>, <a href="#rfc.xref.RFC5322.2">6.5.1</a>, <a href="#rfc.xref.RFC5322.3">8.2.1</a>, <a href="#rfc.xref.RFC5322.4">9.1</a>, <a href="#RFC5322"><b>13.2</b></a>, <a href="#rfc.xref.RFC5322.5">A</a><ul>
     5298                        <li><em>Section 3.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5322.4">9.1</a></li>
     5299                        <li><em>Section 3.4</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5322.1">6.5.1</a>, <a href="#rfc.xref.RFC5322.2">6.5.1</a></li>
     5300                        <li><em>Section 3.6.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5322.3">8.2.1</a></li>
    52955301                     </ul>
    52965302                  </li>
    5297                   <li><em>RFC5646</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5646.1">9.6</a>, <a href="#rfc.xref.RFC5646.2">9.6</a>, <a href="#rfc.xref.RFC5646.3">9.6</a>, <a href="#RFC5646"><b>14.1</b></a><ul>
     5303                  <li><em>RFC5646</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5646.1">9.6</a>, <a href="#rfc.xref.RFC5646.2">9.6</a>, <a href="#rfc.xref.RFC5646.3">9.6</a>, <a href="#RFC5646"><b>13.1</b></a><ul>
    52985304                        <li><em>Section 2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5646.2">9.6</a></li>
    52995305                     </ul>
    53005306                  </li>
    5301                   <li><em>RFC5789</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5789.1">5.3.4</a>, <a href="#RFC5789"><b>14.2</b></a></li>
    5302                   <li><em>RFC5987</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5987.1">11.3.1</a>, <a href="#RFC5987"><b>14.2</b></a></li>
    5303                   <li><em>RFC6151</em>&nbsp;&nbsp;<a href="#RFC6151"><b>14.2</b></a>, <a href="#rfc.xref.RFC6151.1">C</a></li>
    5304                   <li><em>RFC6266</em>&nbsp;&nbsp;<a href="#RFC6266"><b>14.2</b></a>, <a href="#rfc.xref.RFC6266.1">B</a>, <a href="#rfc.xref.RFC6266.2">C</a></li>
     5307                  <li><em>RFC5789</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5789.1">5.3.4</a>, <a href="#RFC5789"><b>13.2</b></a></li>
     5308                  <li><em>RFC5987</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5987.1">10.3.1</a>, <a href="#RFC5987"><b>13.2</b></a></li>
     5309                  <li><em>RFC6151</em>&nbsp;&nbsp;<a href="#RFC6151"><b>13.2</b></a>, <a href="#rfc.xref.RFC6151.1">C</a></li>
     5310                  <li><em>RFC6266</em>&nbsp;&nbsp;<a href="#RFC6266"><b>13.2</b></a>, <a href="#rfc.xref.RFC6266.1">B</a>, <a href="#rfc.xref.RFC6266.2">C</a></li>
    53055311               </ul>
    53065312            </li>
    53075313            <li><a id="rfc.index.S" href="#rfc.index.S"><b>S</b></a><ul>
    53085314                  <li>safe&nbsp;&nbsp;<a href="#rfc.iref.s.2"><b>5.2.1</b></a></li>
    5309                   <li>selected representation&nbsp;&nbsp;<a href="#rfc.iref.s.1"><b>3.2</b></a></li>
    5310                   <li>Server header field&nbsp;&nbsp;<a href="#rfc.xref.header.server.1">8.4</a>, <a href="#rfc.iref.s.44"><b>10.17</b></a>, <a href="#rfc.xref.header.server.2">11.3.2</a>, <a href="#rfc.xref.header.server.3">12.1</a>, <a href="#rfc.xref.header.server.4">C</a></li>
     5315                  <li>selected representation&nbsp;&nbsp;<a href="#rfc.iref.s.1"><b>3.3</b></a></li>
     5316                  <li>Server header field&nbsp;&nbsp;<a href="#rfc.xref.header.server.1">8.4</a>, <a href="#rfc.iref.s.44"><b>8.4.2</b></a>, <a href="#rfc.xref.header.server.2">10.3.2</a>, <a href="#rfc.xref.header.server.3">11.1</a>, <a href="#rfc.xref.header.server.4">C</a></li>
    53115317                  <li>Status Codes&nbsp;&nbsp;
    53125318                     <ul>
    5313                         <li>100 Continue&nbsp;&nbsp;<a href="#rfc.xref.status.100.1">7.1</a>, <a href="#rfc.iref.s.4"><b>7.2.1</b></a>, <a href="#rfc.xref.status.100.2">11.2.3</a></li>
    5314                         <li>101 Switching Protocols&nbsp;&nbsp;<a href="#rfc.xref.status.101.1">7.1</a>, <a href="#rfc.iref.s.5"><b>7.2.2</b></a>, <a href="#rfc.xref.status.101.2">11.2.3</a></li>
    5315                         <li>200 OK&nbsp;&nbsp;<a href="#rfc.xref.status.200.1">7.1</a>, <a href="#rfc.iref.s.7"><b>7.3.1</b></a>, <a href="#rfc.xref.status.200.2">11.2.3</a></li>
    5316                         <li>201 Created&nbsp;&nbsp;<a href="#rfc.xref.status.201.1">7.1</a>, <a href="#rfc.iref.s.8"><b>7.3.2</b></a>, <a href="#rfc.xref.status.201.2">11.2.3</a></li>
    5317                         <li>202 Accepted&nbsp;&nbsp;<a href="#rfc.xref.status.202.1">7.1</a>, <a href="#rfc.iref.s.9"><b>7.3.3</b></a>, <a href="#rfc.xref.status.202.2">11.2.3</a></li>
    5318                         <li>203 Non-Authoritative Information&nbsp;&nbsp;<a href="#rfc.xref.status.203.1">7.1</a>, <a href="#rfc.iref.s.10"><b>7.3.4</b></a>, <a href="#rfc.xref.status.203.2">11.2.3</a>, <a href="#rfc.xref.status.203.3">C</a></li>
    5319                         <li>204 No Content&nbsp;&nbsp;<a href="#rfc.xref.status.204.1">7.1</a>, <a href="#rfc.iref.s.11"><b>7.3.5</b></a>, <a href="#rfc.xref.status.204.2">11.2.3</a></li>
    5320                         <li>205 Reset Content&nbsp;&nbsp;<a href="#rfc.xref.status.205.1">7.1</a>, <a href="#rfc.iref.s.12"><b>7.3.6</b></a>, <a href="#rfc.xref.status.205.2">11.2.3</a></li>
    5321                         <li>300 Multiple Choices&nbsp;&nbsp;<a href="#rfc.xref.status.300.1">7.1</a>, <a href="#rfc.iref.s.14"><b>7.4.1</b></a>, <a href="#rfc.xref.status.300.2">11.2.3</a></li>
    5322                         <li>301 Moved Permanently&nbsp;&nbsp;<a href="#rfc.xref.status.301.1">7.1</a>, <a href="#rfc.iref.s.15"><b>7.4.2</b></a>, <a href="#rfc.xref.status.301.2">11.2.3</a>, <a href="#rfc.xref.status.301.3">C</a></li>
    5323                         <li>302 Found&nbsp;&nbsp;<a href="#rfc.xref.status.302.1">7.1</a>, <a href="#rfc.iref.s.16"><b>7.4.3</b></a>, <a href="#rfc.xref.status.302.2">11.2.3</a>, <a href="#rfc.xref.status.302.3">C</a></li>
    5324                         <li>303 See Other&nbsp;&nbsp;<a href="#rfc.xref.status.303.1">7.1</a>, <a href="#rfc.iref.s.17"><b>7.4.4</b></a>, <a href="#rfc.xref.status.303.2">11.2.3</a></li>
    5325                         <li>305 Use Proxy&nbsp;&nbsp;<a href="#rfc.xref.status.305.1">7.1</a>, <a href="#rfc.iref.s.18"><b>7.4.5</b></a>, <a href="#rfc.xref.status.305.2">11.2.3</a>, <a href="#rfc.xref.status.305.3">C</a></li>
    5326                         <li>306 (Unused)&nbsp;&nbsp;<a href="#rfc.iref.s.19"><b>7.4.6</b></a>, <a href="#rfc.xref.status.306.1">11.2.3</a></li>
    5327                         <li>307 Temporary Redirect&nbsp;&nbsp;<a href="#rfc.xref.status.307.1">7.1</a>, <a href="#rfc.iref.s.20"><b>7.4.7</b></a>, <a href="#rfc.xref.status.307.2">11.2.3</a>, <a href="#rfc.xref.status.307.3">C</a></li>
    5328                         <li>400 Bad Request&nbsp;&nbsp;<a href="#rfc.xref.status.400.1">7.1</a>, <a href="#rfc.iref.s.22"><b>7.5.1</b></a>, <a href="#rfc.xref.status.400.2">11.2.3</a></li>
    5329                         <li>402