Changeset 1923


Ignore:
Timestamp:
01/10/12 07:39:45 (8 years ago)
Author:
fielding@…
Message:

(editorial) move protocol elements up near their primary use in fields

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

Legend:

Unmodified
Added
Removed

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

    r1922 r1923  
    449449  }
    450450  @bottom-center {
    451        content: "Expires April 3, 2013";
     451       content: "Expires March 2013";
    452452  }
    453453  @bottom-right {
    … …  
    474474      <link rel="Chapter" title="2 Resource" href="#rfc.section.2">
    475475      <link rel="Chapter" title="3 Representation" href="#rfc.section.3">
    476       <link rel="Chapter" title="4 Request Methods" href="#rfc.section.4">
    477       <link rel="Chapter" title="5 Request Header Fields" href="#rfc.section.5">
    478       <link rel="Chapter" title="6 Response Status Codes" href="#rfc.section.6">
    479       <link rel="Chapter" title="7 Response Header Fields" href="#rfc.section.7">
    480       <link rel="Chapter" title="8 Protocol Parameters" href="#rfc.section.8">
     476      <link rel="Chapter" title="4 Product Tokens" href="#rfc.section.4">
     477      <link rel="Chapter" title="5 Request Methods" href="#rfc.section.5">
     478      <link rel="Chapter" title="6 Request Header Fields" href="#rfc.section.6">
     479      <link rel="Chapter" title="7 Response Status Codes" href="#rfc.section.7">
     480      <link rel="Chapter" title="8 Response Header Fields" href="#rfc.section.8">
    481481      <link rel="Chapter" title="9 IANA Considerations" href="#rfc.section.9">
    482482      <link rel="Chapter" title="10 Security Considerations" href="#rfc.section.10">
    … …  
    496496      <meta name="dct.creator" content="Reschke, J. F.">
    497497      <meta name="dct.identifier" content="urn:ietf:id:draft-ietf-httpbis-p2-semantics-latest">
    498       <meta name="dct.issued" scheme="ISO8601" content="2012-09-30">
     498      <meta name="dct.issued" scheme="ISO8601" content="2012-09">
    499499      <meta name="dct.replaces" content="urn:ietf:rfc:2616">
    500500      <meta name="dct.abstract" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypertext information systems. This document defines the semantics of HTTP/1.1 messages, as expressed by request methods, request header fields, response status codes, and response header fields, along with the payload of messages (metadata and body content) and mechanisms for content negotiation.">
    … …  
    524524            <tr>
    525525               <td class="left">Intended status: Standards Track</td>
    526                <td class="right">September 30, 2012</td>
     526               <td class="right">September 2012</td>
    527527            </tr>
    528528            <tr>
    529                <td class="left">Expires: April 3, 2013</td>
     529               <td class="left">Expires: March 2013</td>
    530530               <td class="right"></td>
    531531            </tr>
    … …  
    555555         in progress”.
    556556      </p>
    557       <p>This Internet-Draft will expire on April 3, 2013.</p>
     557      <p>This Internet-Draft will expire in March 2013.</p>
    558558      <h1><a id="rfc.copyrightnotice" href="#rfc.copyrightnotice">Copyright Notice</a></h1>
    559559      <p>Copyright © 2012 IETF Trust and the persons identified as the document authors. All rights reserved.</p>
    … …  
    580580         <li><a href="#rfc.section.2">2.</a>&nbsp;&nbsp;&nbsp;<a href="#resource">Resource</a></li>
    581581         <li><a href="#rfc.section.3">3.</a>&nbsp;&nbsp;&nbsp;<a href="#representation">Representation</a><ul>
    582                <li><a href="#rfc.section.3.1">3.1</a>&nbsp;&nbsp;&nbsp;<a href="#representation.header.fields">Representation Header Fields</a><ul>
    583                      <li><a href="#rfc.section.3.1.1">3.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-type">Content-Type</a></li>
    584                      <li><a href="#rfc.section.3.1.2">3.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-encoding">Content-Encoding</a></li>
    585                      <li><a href="#rfc.section.3.1.3">3.1.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-language">Content-Language</a></li>
    586                      <li><a href="#rfc.section.3.1.4">3.1.4</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-location">Content-Location</a></li>
     582               <li><a href="#rfc.section.3.1">3.1</a>&nbsp;&nbsp;&nbsp;<a href="#representation.metadata">Representation Metadata</a><ul>
     583                     <li><a href="#rfc.section.3.1.1">3.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#data.type">Data Type</a><ul>
     584                           <li><a href="#rfc.section.3.1.1.1">3.1.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#media.types">Media Types</a></li>
     585                           <li><a href="#rfc.section.3.1.1.2">3.1.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#character.sets">Character Encodings (charset)</a></li>
     586                           <li><a href="#rfc.section.3.1.1.3">3.1.1.3</a>&nbsp;&nbsp;&nbsp;<a href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></li>
     587                           <li><a href="#rfc.section.3.1.1.4">3.1.1.4</a>&nbsp;&nbsp;&nbsp;<a href="#multipart.types">Multipart Types</a></li>
     588                           <li><a href="#rfc.section.3.1.1.5">3.1.1.5</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-type">Content-Type</a></li>
     589                        </ul>
     590                     </li>
     591                     <li><a href="#rfc.section.3.1.2">3.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#data.encoding">Data Encoding</a><ul>
     592                           <li><a href="#rfc.section.3.1.2.1">3.1.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#content.codings">Content Codings</a></li>
     593                           <li><a href="#rfc.section.3.1.2.2">3.1.2.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-encoding">Content-Encoding</a></li>
     594                        </ul>
     595                     </li>
     596                     <li><a href="#rfc.section.3.1.3">3.1.3</a>&nbsp;&nbsp;&nbsp;<a href="#audience.language">Audience Language</a><ul>
     597                           <li><a href="#rfc.section.3.1.3.1">3.1.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#language.tags">Language Tags</a></li>
     598                           <li><a href="#rfc.section.3.1.3.2">3.1.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-language">Content-Language</a></li>
     599                        </ul>
     600                     </li>
     601                     <li><a href="#rfc.section.3.1.4">3.1.4</a>&nbsp;&nbsp;&nbsp;<a href="#identification">Identification</a><ul>
     602                           <li><a href="#rfc.section.3.1.4.1">3.1.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#identifying.payload">Identifying the Payload</a></li>
     603                           <li><a href="#rfc.section.3.1.4.2">3.1.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-location">Content-Location</a></li>
     604                        </ul>
     605                     </li>
    587606                  </ul>
    588607               </li>
    589608               <li><a href="#rfc.section.3.2">3.2</a>&nbsp;&nbsp;&nbsp;<a href="#representation.data">Representation Data</a></li>
    590                <li><a href="#rfc.section.3.3">3.3</a>&nbsp;&nbsp;&nbsp;<a href="#payload">Message Payload</a><ul>
    591                      <li><a href="#rfc.section.3.3.1">3.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#payload.header.fields">Payload Header Fields</a></li>
    592                      <li><a href="#rfc.section.3.3.2">3.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#identifying.payload">Identifying the Payload</a></li>
    593                   </ul>
    594                </li>
     609               <li><a href="#rfc.section.3.3">3.3</a>&nbsp;&nbsp;&nbsp;<a href="#payload">Payload Semantics</a></li>
    595610               <li><a href="#rfc.section.3.4">3.4</a>&nbsp;&nbsp;&nbsp;<a href="#content.negotiation">Content Negotiation</a><ul>
    596611                     <li><a href="#rfc.section.3.4.1">3.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#proactive.negotiation">Proactive Negotiation</a></li>
    … …  
    600615            </ul>
    601616         </li>
    602          <li><a href="#rfc.section.4">4.</a>&nbsp;&nbsp;&nbsp;<a href="#methods">Request Methods</a><ul>
    603                <li><a href="#rfc.section.4.1">4.1</a>&nbsp;&nbsp;&nbsp;<a href="#method.overview">Overview</a></li>
    604                <li><a href="#rfc.section.4.2">4.2</a>&nbsp;&nbsp;&nbsp;<a href="#method.properties">Common Method Properties</a><ul>
    605                      <li><a href="#rfc.section.4.2.1">4.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#safe.methods">Safe Methods</a></li>
    606                      <li><a href="#rfc.section.4.2.2">4.2.2</a>&nbsp;&nbsp;&nbsp;<a href="#idempotent.methods">Idempotent Methods</a></li>
    607                      <li><a href="#rfc.section.4.2.3">4.2.3</a>&nbsp;&nbsp;&nbsp;<a href="#cacheable.methods">Cacheable Methods</a></li>
     617         <li><a href="#rfc.section.4">4.</a>&nbsp;&nbsp;&nbsp;<a href="#product.tokens">Product Tokens</a></li>
     618         <li><a href="#rfc.section.5">5.</a>&nbsp;&nbsp;&nbsp;<a href="#methods">Request Methods</a><ul>
     619               <li><a href="#rfc.section.5.1">5.1</a>&nbsp;&nbsp;&nbsp;<a href="#method.overview">Overview</a></li>
     620               <li><a href="#rfc.section.5.2">5.2</a>&nbsp;&nbsp;&nbsp;<a href="#method.properties">Common Method Properties</a><ul>
     621                     <li><a href="#rfc.section.5.2.1">5.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#safe.methods">Safe Methods</a></li>
     622                     <li><a href="#rfc.section.5.2.2">5.2.2</a>&nbsp;&nbsp;&nbsp;<a href="#idempotent.methods">Idempotent Methods</a></li>
     623                     <li><a href="#rfc.section.5.2.3">5.2.3</a>&nbsp;&nbsp;&nbsp;<a href="#cacheable.methods">Cacheable Methods</a></li>
    608624                  </ul>
    609625               </li>
    610                <li><a href="#rfc.section.4.3">4.3</a>&nbsp;&nbsp;&nbsp;<a href="#method.definitions">Method Definitions</a><ul>
    611                      <li><a href="#rfc.section.4.3.1">4.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#GET">GET</a></li>
    612                      <li><a href="#rfc.section.4.3.2">4.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#HEAD">HEAD</a></li>
    613                      <li><a href="#rfc.section.4.3.3">4.3.3</a>&nbsp;&nbsp;&nbsp;<a href="#POST">POST</a></li>
    614                      <li><a href="#rfc.section.4.3.4">4.3.4</a>&nbsp;&nbsp;&nbsp;<a href="#PUT">PUT</a></li>
    615                      <li><a href="#rfc.section.4.3.5">4.3.5</a>&nbsp;&nbsp;&nbsp;<a href="#DELETE">DELETE</a></li>
    616                      <li><a href="#rfc.section.4.3.6">4.3.6</a>&nbsp;&nbsp;&nbsp;<a href="#CONNECT">CONNECT</a></li>
    617                      <li><a href="#rfc.section.4.3.7">4.3.7</a>&nbsp;&nbsp;&nbsp;<a href="#OPTIONS">OPTIONS</a></li>
    618                      <li><a href="#rfc.section.4.3.8">4.3.8</a>&nbsp;&nbsp;&nbsp;<a href="#TRACE">TRACE</a></li>
     626               <li><a href="#rfc.section.5.3">5.3</a>&nbsp;&nbsp;&nbsp;<a href="#method.definitions">Method Definitions</a><ul>
     627                     <li><a href="#rfc.section.5.3.1">5.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#GET">GET</a></li>
     628                     <li><a href="#rfc.section.5.3.2">5.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#HEAD">HEAD</a></li>
     629                     <li><a href="#rfc.section.5.3.3">5.3.3</a>&nbsp;&nbsp;&nbsp;<a href="#POST">POST</a></li>
     630                     <li><a href="#rfc.section.5.3.4">5.3.4</a>&nbsp;&nbsp;&nbsp;<a href="#PUT">PUT</a></li>
     631                     <li><a href="#rfc.section.5.3.5">5.3.5</a>&nbsp;&nbsp;&nbsp;<a href="#DELETE">DELETE</a></li>
     632                     <li><a href="#rfc.section.5.3.6">5.3.6</a>&nbsp;&nbsp;&nbsp;<a href="#CONNECT">CONNECT</a></li>
     633                     <li><a href="#rfc.section.5.3.7">5.3.7</a>&nbsp;&nbsp;&nbsp;<a href="#OPTIONS">OPTIONS</a></li>
     634                     <li><a href="#rfc.section.5.3.8">5.3.8</a>&nbsp;&nbsp;&nbsp;<a href="#TRACE">TRACE</a></li>
    619635                  </ul>
    620636               </li>
    621637            </ul>
    622638         </li>
    623          <li><a href="#rfc.section.5">5.</a>&nbsp;&nbsp;&nbsp;<a href="#request.header.fields">Request Header Fields</a><ul>
    624                <li><a href="#rfc.section.5.1">5.1</a>&nbsp;&nbsp;&nbsp;<a href="#request.controls">Controls</a><ul>
    625                      <li><a href="#rfc.section.5.1.1">5.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.max-forwards">Max-Forwards</a></li>
    626                      <li><a href="#rfc.section.5.1.2">5.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.expect">Expect</a><ul>
    627                            <li><a href="#rfc.section.5.1.2.1">5.1.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></li>
     639         <li><a href="#rfc.section.6">6.</a>&nbsp;&nbsp;&nbsp;<a href="#request.header.fields">Request Header Fields</a><ul>
     640               <li><a href="#rfc.section.6.1">6.1</a>&nbsp;&nbsp;&nbsp;<a href="#request.controls">Controls</a><ul>
     641                     <li><a href="#rfc.section.6.1.1">6.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.max-forwards">Max-Forwards</a></li>
     642                     <li><a href="#rfc.section.6.1.2">6.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.expect">Expect</a><ul>
     643                           <li><a href="#rfc.section.6.1.2.1">6.1.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></li>
    628644                        </ul>
    629645                     </li>
    630646                  </ul>
    631647               </li>
    632                <li><a href="#rfc.section.5.2">5.2</a>&nbsp;&nbsp;&nbsp;<a href="#request.conditionals">Conditionals</a></li>
    633                <li><a href="#rfc.section.5.3">5.3</a>&nbsp;&nbsp;&nbsp;<a href="#request.conneg">Content Negotiation</a><ul>
    634                      <li><a href="#rfc.section.5.3.1">5.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#quality.values">Quality Values</a></li>
    635                      <li><a href="#rfc.section.5.3.2">5.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept">Accept</a></li>
    636                      <li><a href="#rfc.section.5.3.3">5.3.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-charset">Accept-Charset</a></li>
    637                      <li><a href="#rfc.section.5.3.4">5.3.4</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-encoding">Accept-Encoding</a></li>
    638                      <li><a href="#rfc.section.5.3.5">5.3.5</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-language">Accept-Language</a></li>
     648               <li><a href="#rfc.section.6.2">6.2</a>&nbsp;&nbsp;&nbsp;<a href="#request.conditionals">Conditionals</a></li>
     649               <li><a href="#rfc.section.6.3">6.3</a>&nbsp;&nbsp;&nbsp;<a href="#request.conneg">Content Negotiation</a><ul>
     650                     <li><a href="#rfc.section.6.3.1">6.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#quality.values">Quality Values</a></li>
     651                     <li><a href="#rfc.section.6.3.2">6.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept">Accept</a></li>
     652                     <li><a href="#rfc.section.6.3.3">6.3.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-charset">Accept-Charset</a></li>
     653                     <li><a href="#rfc.section.6.3.4">6.3.4</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-encoding">Accept-Encoding</a></li>
     654                     <li><a href="#rfc.section.6.3.5">6.3.5</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-language">Accept-Language</a></li>
    639655                  </ul>
    640656               </li>
    641                <li><a href="#rfc.section.5.4">5.4</a>&nbsp;&nbsp;&nbsp;<a href="#request.auth">Authentication</a></li>
    642                <li><a href="#rfc.section.5.5">5.5</a>&nbsp;&nbsp;&nbsp;<a href="#request.context">Context</a><ul>
    643                      <li><a href="#rfc.section.5.5.1">5.5.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.from">From</a></li>
    644                      <li><a href="#rfc.section.5.5.2">5.5.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.referer">Referer</a></li>
    645                      <li><a href="#rfc.section.5.5.3">5.5.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.user-agent">User-Agent</a></li>
     657               <li><a href="#rfc.section.6.4">6.4</a>&nbsp;&nbsp;&nbsp;<a href="#request.auth">Authentication Credentials</a></li>
     658               <li><a href="#rfc.section.6.5">6.5</a>&nbsp;&nbsp;&nbsp;<a href="#request.context">Context</a><ul>
     659                     <li><a href="#rfc.section.6.5.1">6.5.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.from">From</a></li>
     660                     <li><a href="#rfc.section.6.5.2">6.5.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.referer">Referer</a></li>
     661                     <li><a href="#rfc.section.6.5.3">6.5.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.user-agent">User-Agent</a></li>
    646662                  </ul>
    647663               </li>
    648664            </ul>
    649665         </li>
    650          <li><a href="#rfc.section.6">6.</a>&nbsp;&nbsp;&nbsp;<a href="#status.codes">Response Status Codes</a><ul>
    651                <li><a href="#rfc.section.6.1">6.1</a>&nbsp;&nbsp;&nbsp;<a href="#overview.of.status.codes">Overview of Status Codes</a></li>
    652                <li><a href="#rfc.section.6.2">6.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.1xx">Informational 1xx</a><ul>
    653                      <li><a href="#rfc.section.6.2.1">6.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.100">100 Continue</a></li>
    654                      <li><a href="#rfc.section.6.2.2">6.2.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.101">101 Switching Protocols</a></li>
     666         <li><a href="#rfc.section.7">7.</a>&nbsp;&nbsp;&nbsp;<a href="#status.codes">Response Status Codes</a><ul>
     667               <li><a href="#rfc.section.7.1">7.1</a>&nbsp;&nbsp;&nbsp;<a href="#overview.of.status.codes">Overview of Status Codes</a></li>
     668               <li><a href="#rfc.section.7.2">7.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.1xx">Informational 1xx</a><ul>
     669                     <li><a href="#rfc.section.7.2.1">7.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.100">100 Continue</a></li>
     670                     <li><a href="#rfc.section.7.2.2">7.2.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.101">101 Switching Protocols</a></li>
    655671                  </ul>
    656672               </li>
    657                <li><a href="#rfc.section.6.3">6.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.2xx">Successful 2xx</a><ul>
    658                      <li><a href="#rfc.section.6.3.1">6.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.200">200 OK</a></li>
    659                      <li><a href="#rfc.section.6.3.2">6.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.201">201 Created</a></li>
    660                      <li><a href="#rfc.section.6.3.3">6.3.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.202">202 Accepted</a></li>
    661                      <li><a href="#rfc.section.6.3.4">6.3.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.203">203 Non-Authoritative Information</a></li>
    662                      <li><a href="#rfc.section.6.3.5">6.3.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.204">204 No Content</a></li>
    663                      <li><a href="#rfc.section.6.3.6">6.3.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.205">205 Reset Content</a></li>
     673               <li><a href="#rfc.section.7.3">7.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.2xx">Successful 2xx</a><ul>
     674                     <li><a href="#rfc.section.7.3.1">7.3.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.200">200 OK</a></li>
     675                     <li><a href="#rfc.section.7.3.2">7.3.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.201">201 Created</a></li>
     676                     <li><a href="#rfc.section.7.3.3">7.3.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.202">202 Accepted</a></li>
     677                     <li><a href="#rfc.section.7.3.4">7.3.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.203">203 Non-Authoritative Information</a></li>
     678                     <li><a href="#rfc.section.7.3.5">7.3.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.204">204 No Content</a></li>
     679                     <li><a href="#rfc.section.7.3.6">7.3.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.205">205 Reset Content</a></li>
    664680                  </ul>
    665681               </li>
    666                <li><a href="#rfc.section.6.4">6.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.3xx">Redirection 3xx</a><ul>
    667                      <li><a href="#rfc.section.6.4.1">6.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.300">300 Multiple Choices</a></li>
    668                      <li><a href="#rfc.section.6.4.2">6.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.301">301 Moved Permanently</a></li>
    669                      <li><a href="#rfc.section.6.4.3">6.4.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.302">302 Found</a></li>
    670                      <li><a href="#rfc.section.6.4.4">6.4.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.303">303 See Other</a></li>
    671                      <li><a href="#rfc.section.6.4.5">6.4.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.305">305 Use Proxy</a></li>
    672                      <li><a href="#rfc.section.6.4.6">6.4.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.306">306 (Unused)</a></li>
    673                      <li><a href="#rfc.section.6.4.7">6.4.7</a>&nbsp;&nbsp;&nbsp;<a href="#status.307">307 Temporary Redirect</a></li>
     682               <li><a href="#rfc.section.7.4">7.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.3xx">Redirection 3xx</a><ul>
     683                     <li><a href="#rfc.section.7.4.1">7.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.300">300 Multiple Choices</a></li>
     684                     <li><a href="#rfc.section.7.4.2">7.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.301">301 Moved Permanently</a></li>
     685                     <li><a href="#rfc.section.7.4.3">7.4.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.302">302 Found</a></li>
     686                     <li><a href="#rfc.section.7.4.4">7.4.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.303">303 See Other</a></li>
     687                     <li><a href="#rfc.section.7.4.5">7.4.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.305">305 Use Proxy</a></li>
     688                     <li><a href="#rfc.section.7.4.6">7.4.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.306">306 (Unused)</a></li>
     689                     <li><a href="#rfc.section.7.4.7">7.4.7</a>&nbsp;&nbsp;&nbsp;<a href="#status.307">307 Temporary Redirect</a></li>
    674690                  </ul>
    675691               </li>
    676                <li><a href="#rfc.section.6.5">6.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.4xx">Client Error 4xx</a><ul>
    677                      <li><a href="#rfc.section.6.5.1">6.5.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.400">400 Bad Request</a></li>
    678                      <li><a href="#rfc.section.6.5.2">6.5.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.402">402 Payment Required</a></li>
    679                      <li><a href="#rfc.section.6.5.3">6.5.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.403">403 Forbidden</a></li>
    680                      <li><a href="#rfc.section.6.5.4">6.5.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.404">404 Not Found</a></li>
    681                      <li><a href="#rfc.section.6.5.5">6.5.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.405">405 Method Not Allowed</a></li>
    682                      <li><a href="#rfc.section.6.5.6">6.5.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.406">406 Not Acceptable</a></li>
    683                      <li><a href="#rfc.section.6.5.7">6.5.7</a>&nbsp;&nbsp;&nbsp;<a href="#status.408">408 Request Timeout</a></li>
    684                      <li><a href="#rfc.section.6.5.8">6.5.8</a>&nbsp;&nbsp;&nbsp;<a href="#status.409">409 Conflict</a></li>
    685                      <li><a href="#rfc.section.6.5.9">6.5.9</a>&nbsp;&nbsp;&nbsp;<a href="#status.410">410 Gone</a></li>
    686                      <li><a href="#rfc.section.6.5.10">6.5.10</a>&nbsp;&nbsp;&nbsp;<a href="#status.411">411 Length Required</a></li>
    687                      <li><a href="#rfc.section.6.5.11">6.5.11</a>&nbsp;&nbsp;&nbsp;<a href="#status.413">413 Request Representation Too Large</a></li>
    688                      <li><a href="#rfc.section.6.5.12">6.5.12</a>&nbsp;&nbsp;&nbsp;<a href="#status.414">414 URI Too Long</a></li>
    689                      <li><a href="#rfc.section.6.5.13">6.5.13</a>&nbsp;&nbsp;&nbsp;<a href="#status.415">415 Unsupported Media Type</a></li>
    690                      <li><a href="#rfc.section.6.5.14">6.5.14</a>&nbsp;&nbsp;&nbsp;<a href="#status.417">417 Expectation Failed</a></li>
    691                      <li><a href="#rfc.section.6.5.15">6.5.15</a>&nbsp;&nbsp;&nbsp;<a href="#status.426">426 Upgrade Required</a></li>
     692               <li><a href="#rfc.section.7.5">7.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.4xx">Client Error 4xx</a><ul>
     693                     <li><a href="#rfc.section.7.5.1">7.5.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.400">400 Bad Request</a></li>
     694                     <li><a href="#rfc.section.7.5.2">7.5.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.402">402 Payment Required</a></li>
     695                     <li><a href="#rfc.section.7.5.3">7.5.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.403">403 Forbidden</a></li>
     696                     <li><a href="#rfc.section.7.5.4">7.5.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.404">404 Not Found</a></li>
     697                     <li><a href="#rfc.section.7.5.5">7.5.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.405">405 Method Not Allowed</a></li>
     698                     <li><a href="#rfc.section.7.5.6">7.5.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.406">406 Not Acceptable</a></li>
     699                     <li><a href="#rfc.section.7.5.7">7.5.7</a>&nbsp;&nbsp;&nbsp;<a href="#status.408">408 Request Timeout</a></li>
     700                     <li><a href="#rfc.section.7.5.8">7.5.8</a>&nbsp;&nbsp;&nbsp;<a href="#status.409">409 Conflict</a></li>
     701                     <li><a href="#rfc.section.7.5.9">7.5.9</a>&nbsp;&nbsp;&nbsp;<a href="#status.410">410 Gone</a></li>
     702                     <li><a href="#rfc.section.7.5.10">7.5.10</a>&nbsp;&nbsp;&nbsp;<a href="#status.411">411 Length Required</a></li>
     703                     <li><a href="#rfc.section.7.5.11">7.5.11</a>&nbsp;&nbsp;&nbsp;<a href="#status.413">413 Request Representation Too Large</a></li>
     704                     <li><a href="#rfc.section.7.5.12">7.5.12</a>&nbsp;&nbsp;&nbsp;<a href="#status.414">414 URI Too Long</a></li>
     705                     <li><a href="#rfc.section.7.5.13">7.5.13</a>&nbsp;&nbsp;&nbsp;<a href="#status.415">415 Unsupported Media Type</a></li>
     706                     <li><a href="#rfc.section.7.5.14">7.5.14</a>&nbsp;&nbsp;&nbsp;<a href="#status.417">417 Expectation Failed</a></li>
     707                     <li><a href="#rfc.section.7.5.15">7.5.15</a>&nbsp;&nbsp;&nbsp;<a href="#status.426">426 Upgrade Required</a></li>
    692708                  </ul>
    693709               </li>
    694                <li><a href="#rfc.section.6.6">6.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.5xx">Server Error 5xx</a><ul>
    695                      <li><a href="#rfc.section.6.6.1">6.6.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.500">500 Internal Server Error</a></li>
    696                      <li><a href="#rfc.section.6.6.2">6.6.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.501">501 Not Implemented</a></li>
    697                      <li><a href="#rfc.section.6.6.3">6.6.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.502">502 Bad Gateway</a></li>
    698                      <li><a href="#rfc.section.6.6.4">6.6.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.503">503 Service Unavailable</a></li>
    699                      <li><a href="#rfc.section.6.6.5">6.6.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.504">504 Gateway Timeout</a></li>
    700                      <li><a href="#rfc.section.6.6.6">6.6.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.505">505 HTTP Version Not Supported</a></li>
     710               <li><a href="#rfc.section.7.6">7.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.5xx">Server Error 5xx</a><ul>
     711                     <li><a href="#rfc.section.7.6.1">7.6.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.500">500 Internal Server Error</a></li>
     712                     <li><a href="#rfc.section.7.6.2">7.6.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.501">501 Not Implemented</a></li>
     713                     <li><a href="#rfc.section.7.6.3">7.6.3</a>&nbsp;&nbsp;&nbsp;<a href="#status.502">502 Bad Gateway</a></li>
     714                     <li><a href="#rfc.section.7.6.4">7.6.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.503">503 Service Unavailable</a></li>
     715                     <li><a href="#rfc.section.7.6.5">7.6.5</a>&nbsp;&nbsp;&nbsp;<a href="#status.504">504 Gateway Timeout</a></li>
     716                     <li><a href="#rfc.section.7.6.6">7.6.6</a>&nbsp;&nbsp;&nbsp;<a href="#status.505">505 HTTP Version Not Supported</a></li>
    701717                  </ul>
    702718               </li>
    703719            </ul>
    704720         </li>
    705          <li><a href="#rfc.section.7">7.</a>&nbsp;&nbsp;&nbsp;<a href="#response.header.fields">Response Header Fields</a><ul>
    706                <li><a href="#rfc.section.7.1">7.1</a>&nbsp;&nbsp;&nbsp;<a href="#response.control.data">Control Data</a><ul>
    707                      <li><a href="#rfc.section.7.1.1">7.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.date">Date</a></li>
    708                      <li><a href="#rfc.section.7.1.2">7.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.location">Location</a></li>
    709                      <li><a href="#rfc.section.7.1.3">7.1.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.retry-after">Retry-After</a></li>
     721         <li><a href="#rfc.section.8">8.</a>&nbsp;&nbsp;&nbsp;<a href="#response.header.fields">Response Header Fields</a><ul>
     722               <li><a href="#rfc.section.8.1">8.1</a>&nbsp;&nbsp;&nbsp;<a href="#response.control.data">Control Data</a><ul>
     723                     <li><a href="#rfc.section.8.1.1">8.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#origination.date">Origination Date</a><ul>
     724                           <li><a href="#rfc.section.8.1.1.1">8.1.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#http.date">Date/Time Formats</a></li>
     725                           <li><a href="#rfc.section.8.1.1.2">8.1.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.date">Date</a></li>
     726                        </ul>
     727                     </li>
     728                     <li><a href="#rfc.section.8.1.2">8.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.location">Location</a></li>
     729                     <li><a href="#rfc.section.8.1.3">8.1.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.retry-after">Retry-After</a></li>
    710730                  </ul>
    711731               </li>
    712                <li><a href="#rfc.section.7.2">7.2</a>&nbsp;&nbsp;&nbsp;<a href="#selected.representation">Selected Representation Header Fields</a><ul>
    713                      <li><a href="#rfc.section.7.2.1">7.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.vary">Vary</a></li>
     732               <li><a href="#rfc.section.8.2">8.2</a>&nbsp;&nbsp;&nbsp;<a href="#selected.representation">Selected Representation Header Fields</a><ul>
     733                     <li><a href="#rfc.section.8.2.1">8.2.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.vary">Vary</a></li>
    714734                  </ul>
    715735               </li>
    716                <li><a href="#rfc.section.7.3">7.3</a>&nbsp;&nbsp;&nbsp;<a href="#response.auth">Authentication Challenges</a></li>
    717                <li><a href="#rfc.section.7.4">7.4</a>&nbsp;&nbsp;&nbsp;<a href="#response.inform">Informative</a><ul>
    718                      <li><a href="#rfc.section.7.4.1">7.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.allow">Allow</a></li>
    719                      <li><a href="#rfc.section.7.4.2">7.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.server">Server</a></li>
     736               <li><a href="#rfc.section.8.3">8.3</a>&nbsp;&nbsp;&nbsp;<a href="#response.auth">Authentication Challenges</a></li>
     737               <li><a href="#rfc.section.8.4">8.4</a>&nbsp;&nbsp;&nbsp;<a href="#response.inform">Informative</a><ul>
     738                     <li><a href="#rfc.section.8.4.1">8.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.allow">Allow</a></li>
     739                     <li><a href="#rfc.section.8.4.2">8.4.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.server">Server</a></li>
    720740                  </ul>
    721741               </li>
    722             </ul>
    723          </li>
    724          <li><a href="#rfc.section.8">8.</a>&nbsp;&nbsp;&nbsp;<a href="#protocol.parameters">Protocol Parameters</a><ul>
    725                <li><a href="#rfc.section.8.1">8.1</a>&nbsp;&nbsp;&nbsp;<a href="#http.date">Date/Time Formats</a></li>
    726                <li><a href="#rfc.section.8.2">8.2</a>&nbsp;&nbsp;&nbsp;<a href="#product.tokens">Product Tokens</a></li>
    727                <li><a href="#rfc.section.8.3">8.3</a>&nbsp;&nbsp;&nbsp;<a href="#character.sets">Character Encodings (charset)</a></li>
    728                <li><a href="#rfc.section.8.4">8.4</a>&nbsp;&nbsp;&nbsp;<a href="#content.codings">Content Codings</a></li>
    729                <li><a href="#rfc.section.8.5">8.5</a>&nbsp;&nbsp;&nbsp;<a href="#media.types">Media Types</a><ul>
    730                      <li><a href="#rfc.section.8.5.1">8.5.1</a>&nbsp;&nbsp;&nbsp;<a href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></li>
    731                      <li><a href="#rfc.section.8.5.2">8.5.2</a>&nbsp;&nbsp;&nbsp;<a href="#multipart.types">Multipart Types</a></li>
    732                   </ul>
    733                </li>
    734                <li><a href="#rfc.section.8.6">8.6</a>&nbsp;&nbsp;&nbsp;<a href="#language.tags">Language Tags</a></li>
    735742            </ul>
    736743         </li>
    … …  
    840847      </p>
    841848      <p id="rfc.section.1.p.2">HTTP provides a uniform interface for interacting with resources regardless of their type, nature, or implementation. HTTP
    842          semantics includes the intentions defined by each request method (<a href="#methods" title="Request Methods">Section&nbsp;4</a>), extensions to those semantics that might be described in request header fields (<a href="#request.header.fields" title="Request Header Fields">Section&nbsp;5</a>), the meaning of status codes to indicate a machine-readable response (<a href="#status.codes" title="Response Status Codes">Section&nbsp;6</a>), and other control data and resource metadata that might be given in response header fields (<a href="#response.header.fields" title="Response Header Fields">Section&nbsp;7</a>).
     849         semantics includes the intentions defined by each request method (<a href="#methods" title="Request Methods">Section&nbsp;5</a>), extensions to those semantics that might be described in request header fields (<a href="#request.header.fields" title="Request Header Fields">Section&nbsp;6</a>), the meaning of status codes to indicate a machine-readable response (<a href="#status.codes" title="Response Status Codes">Section&nbsp;7</a>), and other control data and resource metadata that might be given in response header fields (<a href="#response.header.fields" title="Response Header Fields">Section&nbsp;8</a>).
    843850      </p>
    844851      <p id="rfc.section.1.p.3"><span id="rfc.iref.c.1"></span> In addition, this document defines the payload of messages (a.k.a., content), the associated metadata header fields that define
    … …  
    863870      </p>
    864871      <p id="rfc.section.2.p.3">One design goal of HTTP is to separate resource identification from request semantics, which is made possible by vesting the
    865          request semantics in the request method (<a href="#methods" title="Request Methods">Section&nbsp;4</a>) and a few request-modifying header fields (<a href="#request.header.fields" title="Request Header Fields">Section&nbsp;5</a>). Resource owners <em class="bcp14">SHOULD NOT</em> include request semantics within a URI, such as by specifying an action to invoke within the path or query components of the
     872         request semantics in the request method (<a href="#methods" title="Request Methods">Section&nbsp;5</a>) and a few request-modifying header fields (<a href="#request.header.fields" title="Request Header Fields">Section&nbsp;6</a>). Resource owners <em class="bcp14">SHOULD NOT</em> include request semantics within a URI, such as by specifying an action to invoke within the path or query components of the
    866873         effective request URI, unless those semantics are disabled when they are inconsistent with the request method.
    867874      </p>
    … …  
    877884         (representation data).
    878885      </p>
    879       <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a id="representation.header.fields" href="#representation.header.fields">Representation Header Fields</a></h2>
     886      <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a id="representation.metadata" href="#representation.metadata">Representation Metadata</a></h2>
    880887      <p id="rfc.section.3.1.p.1">Representation header fields provide metadata about the representation. When a message includes a payload body, the representation
    881888         header fields describe how to interpret the representation data enclosed in the payload body. In a response to a HEAD request,
    … …  
    883890         same request had been a GET.
    884891      </p>
    885       <p id="rfc.section.3.1.p.2">The following header fields are defined as representation metadata:</p>
     892      <p id="rfc.section.3.1.p.2">The following header fields are defined to convey representation metadata:</p>
    886893      <div id="rfc.table.u.1">
    887894         <table class="tt full left" cellpadding="3" cellspacing="0">
    … …  
    895902               <tr>
    896903                  <td class="left">Content-Type</td>
    897                   <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section&nbsp;3.1.1</a></td>
     904                  <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section&nbsp;3.1.1.5</a></td>
    898905               </tr>
    899906               <tr>
    900907                  <td class="left">Content-Encoding</td>
    901                   <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section&nbsp;3.1.2</a></td>
     908                  <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section&nbsp;3.1.2.2</a></td>
    902909               </tr>
    903910               <tr>
    904911                  <td class="left">Content-Language</td>
    905                   <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section&nbsp;3.1.3</a></td>
     912                  <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section&nbsp;3.1.3.2</a></td>
    906913               </tr>
    907914               <tr>
    908915                  <td class="left">Content-Location</td>
    909                   <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section&nbsp;3.1.4</a></td>
     916                  <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section&nbsp;3.1.4.2</a></td>
    910917               </tr>
    911918               <tr>
    … …  
    916923         </table>
    917924      </div>
     925      <h3 id="rfc.section.3.1.1"><a href="#rfc.section.3.1.1">3.1.1</a>&nbsp;<a id="data.type" href="#data.type">Data Type</a></h3>
     926      <h4 id="rfc.section.3.1.1.1"><a href="#rfc.section.3.1.1.1">3.1.1.1</a>&nbsp;<a id="media.types" href="#media.types">Media Types</a></h4>
     927      <p id="rfc.section.3.1.1.1.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.1"><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.2" title="Content-Type">Section&nbsp;3.1.1.5</a>) and <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>) header fields in order to provide open and extensible data typing and type negotiation.
     928      </p>
     929      <div id="rfc.figure.u.1"></div><pre class="inline"><span id="rfc.iref.g.1"></span><span id="rfc.iref.g.2"></span><span id="rfc.iref.g.3"></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> )
     930  <a href="#media.types" class="smpl">type</a>       = <a href="#imported.abnf" class="smpl">token</a>
     931  <a href="#media.types" class="smpl">subtype</a>    = <a href="#imported.abnf" class="smpl">token</a>
     932</pre><div id="rule.parameter">
     933         <p id="rfc.section.3.1.1.1.p.3">      The type/subtype <em class="bcp14">MAY</em> be followed by parameters in the form of attribute/value pairs.
     934         </p>
     935      </div>
     936      <div id="rfc.figure.u.2"></div><pre class="inline"><span id="rfc.iref.g.4"></span><span id="rfc.iref.g.5"></span><span id="rfc.iref.g.6"></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>
     937  <a href="#rule.parameter" class="smpl">attribute</a>      = <a href="#imported.abnf" class="smpl">token</a>
     938  <a href="#rule.parameter" class="smpl">value</a>          = <a href="#imported.abnf" class="smpl">word</a>
     939</pre><p id="rfc.section.3.1.1.1.p.5">The type, subtype, and parameter attribute names are case-insensitive. Parameter values might or might not be case-sensitive,
     940         depending on the semantics of the parameter name. The presence or absence of a parameter might be significant to the processing
     941         of a media-type, depending on its definition within the media type registry.
     942      </p>
     943      <p id="rfc.section.3.1.1.1.p.6">A parameter value that matches the <a href="#imported.abnf" class="smpl">token</a> production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent.
     944      </p>
     945      <p id="rfc.section.3.1.1.1.p.7">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is
     946         outlined in <a href="#RFC4288" id="rfc.xref.RFC4288.1"><cite title="Media Type Specifications and Registration Procedures">[RFC4288]</cite></a>. Use of non-registered media types is discouraged.
     947      </p>
     948      <h4 id="rfc.section.3.1.1.2"><a href="#rfc.section.3.1.1.2">3.1.1.2</a>&nbsp;<a id="character.sets" href="#character.sets">Character Encodings (charset)</a></h4>
     949      <p id="rfc.section.3.1.1.2.p.1">HTTP uses charset names to indicate the character encoding of a textual representation.</p>
     950      <div id="rule.charset">
     951         <p id="rfc.section.3.1.1.2.p.2">  A character encoding is identified by a case-insensitive token. The complete set of tokens is defined by the IANA Character
     952            Set registry (&lt;<a href="http://www.iana.org/assignments/character-sets">http://www.iana.org/assignments/character-sets</a>&gt;).
     953         </p>
     954      </div>
     955      <div id="rfc.figure.u.3"></div><pre class="inline"><span id="rfc.iref.g.7"></span>  <a href="#rule.charset" class="smpl">charset</a> = <a href="#imported.abnf" class="smpl">token</a>
     956</pre><p id="rfc.section.3.1.1.2.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
     957         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.
     958      </p>
     959      <p id="rfc.section.3.1.1.2.p.5">HTTP uses charset in two contexts: within an <a href="#header.accept-charset" class="smpl">Accept-Charset</a> request header field (in which the charset value is an unquoted token) and as the value of a parameter in a <a href="#header.content-type" class="smpl">Content-Type</a> header field (within a request or response), in which case the parameter value of the charset parameter can be quoted.
     960      </p>
     961      <p id="rfc.section.3.1.1.2.p.6">Implementers need to be aware of IETF character set requirements <a href="#RFC3629" id="rfc.xref.RFC3629.1"><cite title="UTF-8, a transformation format of ISO 10646">[RFC3629]</cite></a>  <a href="#RFC2277" id="rfc.xref.RFC2277.1"><cite title="IETF Policy on Character Sets and Languages">[RFC2277]</cite></a>.
     962      </p>
     963      <h4 id="rfc.section.3.1.1.3"><a href="#rfc.section.3.1.1.3">3.1.1.3</a>&nbsp;<a id="canonicalization.and.text.defaults" href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></h4>
     964      <p id="rfc.section.3.1.1.3.p.1">Internet media types are registered with a canonical form. A representation transferred via HTTP messages <em class="bcp14">MUST</em> be in the appropriate canonical form prior to its transmission except for "text" types, as defined in the next paragraph.
     965      </p>
     966      <p id="rfc.section.3.1.1.3.p.2">When in canonical form, media subtypes of the "text" type use CRLF as the text line break. HTTP relaxes this requirement and
     967         allows the transport of text media with plain CR or LF alone representing a line break when it is done consistently for an
     968         entire representation. HTTP applications <em class="bcp14">MUST</em> accept CRLF, bare CR, and bare LF as indicating a line break in text media received via HTTP. In addition, if the text is
     969         in a character encoding that does not use octets 13 and 10 for CR and LF respectively, as is the case for some multi-byte
     970         character encodings, HTTP allows the use of whatever octet sequences are defined by that character encoding to represent the
     971         equivalent of CR and LF for line breaks. This flexibility regarding line breaks applies only to text media in the payload
     972         body; a bare CR or LF <em class="bcp14">MUST NOT</em> be substituted for CRLF within any of the HTTP control structures (such as header fields and multipart boundaries).
     973      </p>
     974      <p id="rfc.section.3.1.1.3.p.3">If a representation is encoded with a content-coding, the underlying data <em class="bcp14">MUST</em> be in a form defined above prior to being encoded.
     975      </p>
     976      <h4 id="rfc.section.3.1.1.4"><a href="#rfc.section.3.1.1.4">3.1.1.4</a>&nbsp;<a id="multipart.types" href="#multipart.types">Multipart Types</a></h4>
     977      <p id="rfc.section.3.1.1.4.p.1">MIME provides for a number of "multipart" types — encapsulations of one or more representations within a single message body.
     978         All multipart types share a common syntax, as defined in <a href="http://tools.ietf.org/html/rfc2046#section-5.1.1">Section 5.1.1</a> of <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, and include a boundary parameter as part of the media type value. The message body is itself a protocol element; a sender <em class="bcp14">MUST</em> generate only CRLF to represent line breaks between body-parts.
     979      </p>
     980      <p id="rfc.section.3.1.1.4.p.2">In general, HTTP treats a multipart message body no differently than any other media type: strictly as payload. HTTP does
     981         not use the multipart boundary as an indicator of message body length.  In all other respects, an HTTP user agent <em class="bcp14">SHOULD</em> follow the same or similar behavior as a MIME user agent would upon receipt of a multipart type. The MIME header fields within
     982         each body-part of a multipart message body do not have any significance to HTTP beyond that defined by their MIME semantics.
     983      </p>
     984      <p id="rfc.section.3.1.1.4.p.3">A recipient <em class="bcp14">MUST</em> treat an unrecognized multipart subtype as being equivalent to "multipart/mixed".
     985      </p>
     986      <div class="note" id="rfc.section.3.1.1.4.p.4">
     987         <p> <b>Note:</b> The "multipart/form-data" type has been specifically defined for carrying form data suitable for processing via the POST request
     988            method, as described in <a href="#RFC2388" id="rfc.xref.RFC2388.1"><cite title="Returning Values from Forms: multipart/form-data">[RFC2388]</cite></a>.
     989         </p>
     990      </div>
    918991      <div id="rfc.iref.c.2"></div>
    919       <h3 id="rfc.section.3.1.1"><a href="#rfc.section.3.1.1">3.1.1</a>&nbsp;<a id="header.content-type" href="#header.content-type">Content-Type</a></h3>
    920       <p id="rfc.section.3.1.1.p.1">The "Content-Type" header field indicates the media type of the representation, which defines both the data format and how
     992      <h4 id="rfc.section.3.1.1.5"><a href="#rfc.section.3.1.1.5">3.1.1.5</a>&nbsp;<a id="header.content-type" href="#header.content-type">Content-Type</a></h4>
     993      <p id="rfc.section.3.1.1.5.p.1">The "Content-Type" header field indicates the media type of the representation, which defines both the data format and how
    921994         that data <em class="bcp14">SHOULD</em> be processed by the recipient (within the scope of the request method semantics) after any <a href="#header.content-encoding" class="smpl">Content-Encoding</a> is decoded. For responses to the HEAD method, the media type is that which would have been sent had the request been a GET.
    922995      </p>
    923       <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>
    924 </pre><p id="rfc.section.3.1.1.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section&nbsp;8.5</a>. An example of the field is
    925       </p>
    926       <div id="rfc.figure.u.2"></div><pre class="text">  Content-Type: text/html; charset=ISO-8859-4
    927 </pre><p id="rfc.section.3.1.1.p.5">A sender <em class="bcp14">SHOULD</em> include a Content-Type header field in a message containing a payload body, defining the media type of the enclosed representation,
    928          unless the intended media type is unknown to the sender. If a Content-Type header field is not present, recipients <em class="bcp14">MAY</em> either assume a media type of "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 representation data to determine its type.
    929       </p>
    930       <p id="rfc.section.3.1.1.p.6">In practice, resource owners do not always properly configure their origin server to provide the correct Content-Type for
     996      <div id="rfc.figure.u.4"></div><pre class="inline"><span id="rfc.iref.g.8"></span>  <a href="#header.content-type" class="smpl">Content-Type</a> = <a href="#media.types" class="smpl">media-type</a>
     997</pre><p id="rfc.section.3.1.1.5.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section&nbsp;3.1.1.1</a>. An example of the field is
     998      </p>
     999      <div id="rfc.figure.u.5"></div><pre class="text">  Content-Type: text/html; charset=ISO-8859-4
     1000</pre><p id="rfc.section.3.1.1.5.p.5">A sender <em class="bcp14">SHOULD</em> include a Content-Type header field in a message containing a payload body, defining the media type of the enclosed representation,
     1001         unless the intended media type is unknown to the sender. If a Content-Type header field is not present, recipients <em class="bcp14">MAY</em> either assume a media type of "application/octet-stream" (<a href="#RFC2046" id="rfc.xref.RFC2046.3"><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 representation data to determine its type.
     1002      </p>
     1003      <p id="rfc.section.3.1.1.5.p.6">In practice, resource owners do not always properly configure their origin server to provide the correct Content-Type for
    9311004         a given representation, with the result that some clients will examine a payload's content and override the specified type.
    9321005         Clients that do so risk drawing incorrect conclusions, which might expose additional security risks (e.g., "privilege escalation").
    … …  
    9351008         sniffing" when it is used.
    9361009      </p>
    937       <div id="rfc.iref.c.3"></div>
    938       <h3 id="rfc.section.3.1.2"><a href="#rfc.section.3.1.2">3.1.2</a>&nbsp;<a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h3>
    939       <p id="rfc.section.3.1.2.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent
     1010      <h3 id="rfc.section.3.1.2"><a href="#rfc.section.3.1.2">3.1.2</a>&nbsp;<a id="data.encoding" href="#data.encoding">Data Encoding</a></h3>
     1011      <h4 id="rfc.section.3.1.2.1"><a href="#rfc.section.3.1.2.1">3.1.2.1</a>&nbsp;<a id="content.codings" href="#content.codings">Content Codings</a></h4>
     1012      <p id="rfc.section.3.1.2.1.p.1">Content coding values indicate an encoding transformation that has been or can be applied to a representation. Content codings
     1013         are primarily used to allow a representation to be compressed or otherwise usefully transformed without losing the identity
     1014         of its underlying media type and without loss of information. Frequently, the representation is stored in coded form, transmitted
     1015         directly, and only decoded by the recipient.
     1016      </p>
     1017      <div id="rfc.figure.u.6"></div><pre class="inline"><span id="rfc.iref.g.9"></span>  <a href="#content.codings" class="smpl">content-coding</a>   = <a href="#imported.abnf" class="smpl">token</a>
     1018</pre><p id="rfc.section.3.1.2.1.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.1" 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;3.1.2.2</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding
     1019         mechanism will be required to remove the encoding.
     1020      </p>
     1021      <p id="rfc.section.3.1.2.1.p.4">compress<span id="rfc.iref.c.3"></span> 
     1022      </p>
     1023      <ul class="empty">
     1024         <li>See <a href="p1-messaging.html#compress.coding" title="Compress Coding">Section 4.2.1</a> of <a href="#Part1" id="rfc.xref.Part1.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>.
     1025         </li>
     1026      </ul>
     1027      <p id="rfc.section.3.1.2.1.p.5">deflate<span id="rfc.iref.d.1"></span> 
     1028      </p>
     1029      <ul class="empty">
     1030         <li>See <a href="p1-messaging.html#deflate.coding" title="Deflate Coding">Section 4.2.2</a> of <a href="#Part1" id="rfc.xref.Part1.8"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>.
     1031         </li>
     1032      </ul>
     1033      <p id="rfc.section.3.1.2.1.p.6">gzip<span id="rfc.iref.g.10"></span> 
     1034      </p>
     1035      <ul class="empty">
     1036         <li>See <a href="p1-messaging.html#gzip.coding" title="Gzip Coding">Section 4.2.3</a> of <a href="#Part1" id="rfc.xref.Part1.9"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>.
     1037         </li>
     1038      </ul>
     1039      <div id="rfc.iref.c.4"></div>
     1040      <h4 id="rfc.section.3.1.2.2"><a href="#rfc.section.3.1.2.2">3.1.2.2</a>&nbsp;<a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h4>
     1041      <p id="rfc.section.3.1.2.2.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent
    9401042         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
    9411043         its underlying media type.
    9421044      </p>
    943       <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>
    944 </pre><p id="rfc.section.3.1.2.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section&nbsp;8.4</a>. An example of its use is
    945       </p>
    946       <div id="rfc.figure.u.4"></div><pre class="text">  Content-Encoding: gzip
    947 </pre><p id="rfc.section.3.1.2.p.5">The content-coding is a characteristic of the representation. Typically, the representation data is stored with this encoding
     1045      <div id="rfc.figure.u.7"></div><pre class="inline"><span id="rfc.iref.g.11"></span>  <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = 1#<a href="#content.codings" class="smpl">content-coding</a>
     1046</pre><p id="rfc.section.3.1.2.2.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section&nbsp;3.1.2.1</a>. An example of its use is
     1047      </p>
     1048      <div id="rfc.figure.u.8"></div><pre class="text">  Content-Encoding: gzip
     1049</pre><p id="rfc.section.3.1.2.2.p.5">The content-coding is a characteristic of the representation. Typically, the representation data is stored with this encoding
    9481050         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
    9491051         directive is present in the message.
    9501052      </p>
    951       <p id="rfc.section.3.1.2.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would
     1053      <p id="rfc.section.3.1.2.2.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would
    9521054         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
    9531055         would only be listed if, for some bizarre reason, it is applied a second time to form the representation. Likewise, an origin
    … …  
    9561058         as ..." dialog instead of automatic decompression and rendering of content).
    9571059      </p>
    958       <p id="rfc.section.3.1.2.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.
    959       </p>
    960       <p id="rfc.section.3.1.2.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.
    961       </p>
    962       <p id="rfc.section.3.1.2.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).
    963       </p>
    964       <div id="rfc.iref.c.4"></div>
    965       <h3 id="rfc.section.3.1.3"><a href="#rfc.section.3.1.3">3.1.3</a>&nbsp;<a id="header.content-language" href="#header.content-language">Content-Language</a></h3>
    966       <p id="rfc.section.3.1.3.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note
     1060      <p id="rfc.section.3.1.2.2.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.
     1061      </p>
     1062      <p id="rfc.section.3.1.2.2.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.
     1063      </p>
     1064      <p id="rfc.section.3.1.2.2.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).
     1065      </p>
     1066      <h3 id="rfc.section.3.1.3"><a href="#rfc.section.3.1.3">3.1.3</a>&nbsp;<a id="audience.language" href="#audience.language">Audience Language</a></h3>
     1067      <h4 id="rfc.section.3.1.3.1"><a href="#rfc.section.3.1.3.1">3.1.3.1</a>&nbsp;<a id="language.tags" href="#language.tags">Language Tags</a></h4>
     1068      <p id="rfc.section.3.1.3.1.p.1">A language tag, as defined in <a href="#RFC5646" id="rfc.xref.RFC5646.1"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, identifies a natural language spoken, written, or otherwise conveyed by human beings for communication of information to
     1069         other human beings. Computer languages are explicitly excluded. HTTP uses language tags within the <a href="#header.accept-language" class="smpl">Accept-Language</a> and <a href="#header.content-language" class="smpl">Content-Language</a> fields.
     1070      </p>
     1071      <p id="rfc.section.3.1.3.1.p.2">In summary, a language tag is composed of one or more parts: A primary language subtag followed by a possibly empty series
     1072         of subtags:
     1073      </p>
     1074      <div id="rfc.figure.u.9"></div><pre class="inline"><span id="rfc.iref.g.12"></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;
     1075</pre><p id="rfc.section.3.1.3.1.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered
     1076         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;).
     1077      </p>
     1078      <div id="rfc.figure.u.10"></div>
     1079      <p>Example tags include:</p>  <pre class="text">  en, en-US, es-419, az-Arab, x-pig-latin, man-Nkoo-GN
     1080</pre> <p id="rfc.section.3.1.3.1.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information.
     1081      </p>
     1082      <div id="rfc.iref.c.5"></div>
     1083      <h4 id="rfc.section.3.1.3.2"><a href="#rfc.section.3.1.3.2">3.1.3.2</a>&nbsp;<a id="header.content-language" href="#header.content-language">Content-Language</a></h4>
     1084      <p id="rfc.section.3.1.3.2.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note
    9671085         that this might not be equivalent to all the languages used within the representation.
    9681086      </p>
    969       <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>
    970 </pre><p id="rfc.section.3.1.3.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;8.6</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the
     1087      <div id="rfc.figure.u.11"></div><pre class="inline"><span id="rfc.iref.g.13"></span>  <a href="#header.content-language" class="smpl">Content-Language</a> = 1#<a href="#language.tags" class="smpl">language-tag</a>
     1088</pre><p id="rfc.section.3.1.3.2.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;3.1.3.1</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the
    9711089         user's own preferred language. Thus, if the content is intended only for a Danish-literate audience, the appropriate field
    9721090         is
    9731091      </p>
    974       <div id="rfc.figure.u.6"></div><pre class="text">  Content-Language: da
    975 </pre><p id="rfc.section.3.1.3.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean
     1092      <div id="rfc.figure.u.12"></div><pre class="text">  Content-Language: da
     1093</pre><p id="rfc.section.3.1.3.2.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean
    9761094         that the sender does not consider it to be specific to any natural language, or that the sender does not know for which language
    9771095         it is intended.
    9781096      </p>
    979       <p id="rfc.section.3.1.3.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
     1097      <p id="rfc.section.3.1.3.2.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
    9801098         simultaneously in the original Maori and English versions, would call for
    9811099      </p>
    982       <div id="rfc.figure.u.7"></div><pre class="text">  Content-Language: mi, en
    983 </pre><p id="rfc.section.3.1.3.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple
     1100      <div id="rfc.figure.u.13"></div><pre class="text">  Content-Language: mi, en
     1101</pre><p id="rfc.section.3.1.3.2.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple
    9841102         linguistic audiences. An example would be a beginner's language primer, such as "A First Lesson in Latin", which is clearly
    9851103         intended to be used by an English-literate audience. In this case, the Content-Language would properly only include "en".
    9861104      </p>
    987       <p id="rfc.section.3.1.3.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents.
    988       </p>
    989       <div id="rfc.iref.c.5"></div>
    990       <h3 id="rfc.section.3.1.4"><a href="#rfc.section.3.1.4">3.1.4</a>&nbsp;<a id="header.content-location" href="#header.content-location">Content-Location</a></h3>
    991       <p id="rfc.section.3.1.4.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this
     1105      <p id="rfc.section.3.1.3.2.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents.
     1106      </p>
     1107      <h3 id="rfc.section.3.1.4"><a href="#rfc.section.3.1.4">3.1.4</a>&nbsp;<a id="identification" href="#identification">Identification</a></h3>
     1108      <h4 id="rfc.section.3.1.4.1"><a href="#rfc.section.3.1.4.1">3.1.4.1</a>&nbsp;<a id="identifying.payload" href="#identifying.payload">Identifying the Payload</a></h4>
     1109      <p id="rfc.section.3.1.4.1.p.1">When a complete or partial representation is transferred in a message payload, it is often desirable for the sender to supply,
     1110         or the recipient to determine, an identifier for the resource corresponding to that representation.
     1111      </p>
     1112      <p id="rfc.section.3.1.4.1.p.2">The following rules are used to determine such a URI for the payload of a request message: </p>
     1113      <ul>
     1114         <li>If the request has a <a href="#header.content-location" class="smpl">Content-Location</a> header field, then the sender asserts that the payload is a representation of the resource identified by the Content-Location
     1115            field-value. However, such an assertion cannot be trusted unless it can be verified by other means (not defined by HTTP).
     1116            The information might still be useful for revision history links.
     1117         </li>
     1118         <li>Otherwise, the payload is unidentified.</li>
     1119      </ul>
     1120      <p id="rfc.section.3.1.4.1.p.3">The following rules, to be applied in order until a match is found, are used to determine such a URI for the payload of a
     1121         response message:
     1122      </p>
     1123      <ol>
     1124         <li>If the request is GET or HEAD and the response status code is <a href="#status.200" class="smpl">200 (OK)</a>, <a href="#status.204" class="smpl">204 (No Content)</a>, <a href="p5-range.html#status.206" class="smpl">206 (Partial Content)</a>, or <a href="p4-conditional.html#status.304" class="smpl">304 (Not Modified)</a>, the payload's identifier is 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.Part1.10"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>).
     1125         </li>
     1126         <li>If the request is GET or HEAD and the response status code is <a href="#status.203" class="smpl">203 (Non-Authoritative Information)</a>, the payload is a potentially modified representation of the target resource; as such, the effective request URI might only
     1127            act as an identifier for the payload's representation when a request is made via the same chain of intermediaries.
     1128         </li>
     1129         <li>If the response has a <a href="#header.content-location" class="smpl">Content-Location</a> header field and its field-value is a reference to the same URI as the effective request URI, the payload's identifier is
     1130            the effective request URI.
     1131         </li>
     1132         <li>If the response has a <a href="#header.content-location" class="smpl">Content-Location</a> header field and its field-value is a reference to a URI different from the effective request URI, then the sender asserts
     1133            that the payload is a representation of the resource identified by the Content-Location field-value. However, such an assertion
     1134            cannot be trusted unless it can be verified by other means (not defined by HTTP).
     1135         </li>
     1136         <li>Otherwise, the payload is unidentified.</li>
     1137      </ol>
     1138      <div id="rfc.iref.c.6"></div>
     1139      <h4 id="rfc.section.3.1.4.2"><a href="#rfc.section.3.1.4.2">3.1.4.2</a>&nbsp;<a id="header.content-location" href="#header.content-location">Content-Location</a></h4>
     1140      <p id="rfc.section.3.1.4.2.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this
    9921141         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.
    9931142      </p>
    994       <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>
    995 </pre><p id="rfc.section.3.1.4.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.Part1.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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
     1143      <div id="rfc.figure.u.14"></div><pre class="inline"><span id="rfc.iref.g.14"></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>
     1144</pre><p id="rfc.section.3.1.4.2.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.Part1.11"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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
    9961145         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.
    9971146      </p>
    998       <p id="rfc.section.3.1.4.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
     1147      <p id="rfc.section.3.1.4.2.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
    9991148         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
    10001149         when no Content-Location is provided by the server. For a state-changing request like PUT or POST, it implies that the server's
    … …  
    10031152         need for a subsequent GET request.
    10041153      </p>
    1005       <p id="rfc.section.3.1.4.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin
     1154      <p id="rfc.section.3.1.4.2.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin
    10061155         server is informing recipients that this representation has its own, presumably more specific, identifier. For a GET or HEAD
    10071156         request, this is an indication that the effective request URI identifies a resource that is subject to content negotiation
    … …  
    10111160         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.
    10121161      </p>
    1013       <p id="rfc.section.3.1.4.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
     1162      <p id="rfc.section.3.1.4.2.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
    10141163         representation (prior to any subsequent modification of the content by that user agent). In other words, the user agent is
    10151164         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
    … …  
    10191168         latter semantics, it would have applied the PUT directly to the Content-Location URI.
    10201169      </p>
    1021       <p id="rfc.section.3.1.4.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
     1170      <p id="rfc.section.3.1.4.2.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
    10221171         in other contexts, such as within source links or other metadata.
    10231172      </p>
    1024       <p id="rfc.section.3.1.4.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used
     1173      <p id="rfc.section.3.1.4.2.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used
    10251174         to respond to later requests on that Content-Location URI.
    10261175      </p>
    1027       <p id="rfc.section.3.1.4.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p>
     1176      <p id="rfc.section.3.1.4.2.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p>
    10281177      <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a>&nbsp;<a id="representation.data" href="#representation.data">Representation Data</a></h2>
    10291178      <p id="rfc.section.3.2.p.1">The representation data associated with an HTTP message is either provided as the payload body of the message or referred
    … …  
    10331182      <p id="rfc.section.3.2.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:
    10341183      </p>
    1035       <div id="rfc.figure.u.9"></div><pre class="text">  representation-data := Content-Encoding( Content-Type( bits ) )
     1184      <div id="rfc.figure.u.15"></div><pre class="text">  representation-data := Content-Encoding( Content-Type( bits ) )
    10361185</pre><div id="rfc.iref.p.1"></div>
    1037       <h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="payload" href="#payload">Message Payload</a></h2>
     1186      <h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="payload" href="#payload">Payload Semantics</a></h2>
    10381187      <p id="rfc.section.3.3.p.1">Some HTTP messages transfer a complete or partial representation as the message "<dfn>payload</dfn>". In some cases, a payload might only contain the associated representation's header fields (e.g., responses to HEAD) or
    10391188         only some part(s) of the representation data (e.g., the <a href="p5-range.html#status.206" class="smpl">206 (Partial Content)</a> status code).
    … …  
    10421191         by both the request method and the response status code.
    10431192      </p>
    1044       <p id="rfc.section.3.3.p.3">For example, a representation in the payload of a PUT request (<a href="#PUT" id="rfc.xref.PUT.1" title="PUT">Section&nbsp;4.3.4</a>) represents the desired state of the target resource if the request is successfully applied, whereas a representation in
    1045          the payload of a POST request (<a href="#POST" id="rfc.xref.POST.1" title="POST">Section&nbsp;4.3.3</a>) represents an anonymous resource for providing data to be processed, such as the information that a user entered within
     1193      <p id="rfc.section.3.3.p.3">For example, a representation in the payload of a PUT request (<a href="#PUT" id="rfc.xref.PUT.1" title="PUT">Section&nbsp;5.3.4</a>) represents the desired state of the target resource if the request is successfully applied, whereas a representation in
     1194         the payload of a POST request (<a href="#POST" id="rfc.xref.POST.1" title="POST">Section&nbsp;5.3.3</a>) represents an anonymous resource for providing data to be processed, such as the information that a user entered within
    10461195         an HTML form.
    10471196      </p>
    1048       <p id="rfc.section.3.3.p.4">Likewise, the payload of a <a href="#status.200" class="smpl">200 (OK)</a> response to GET (<a href="#GET" id="rfc.xref.GET.1" title="GET">Section&nbsp;4.3.1</a>) contains a representation of the target resource, as observed at the time of the message origination date (<a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section&nbsp;7.1.1</a>), whereas the same status code in a response to POST might contain either a representation of the processing result or a
     1197      <p id="rfc.section.3.3.p.4">Likewise, the payload of a <a href="#status.200" class="smpl">200 (OK)</a> response to GET (<a href="#GET" id="rfc.xref.GET.1" title="GET">Section&nbsp;5.3.1</a>) contains a representation of the target resource, as observed at the time of the message origination date (<a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section&nbsp;8.1.1.2</a>), whereas the same status code in a response to POST might contain either a representation of the processing result or a
    10491198         current representation of the target resource after applying the processing. Response messages with an error status code usually
    10501199         contain a representation that describes the error and what next steps are suggested for resolving it.
    10511200      </p>
    1052       <h3 id="rfc.section.3.3.1"><a href="#rfc.section.3.3.1">3.3.1</a>&nbsp;<a id="payload.header.fields" href="#payload.header.fields">Payload Header Fields</a></h3>
    1053       <p id="rfc.section.3.3.1.p.1">Header fields that specifically describe the payload, rather than the associated representation, are referred to as "payload
     1201      <p id="rfc.section.3.3.p.5">Header fields that specifically describe the payload, rather than the associated representation, are referred to as "payload
    10541202         header fields". Payload header fields are defined in other parts of this specification, due to their impact on message parsing.
    10551203      </p>
    … …  
    10651213               <tr>
    10661214                  <td class="left">Content-Length</td>
    1067                   <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.Part1.8"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a></td>
     1215                  <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.Part1.12"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a></td>
    10681216               </tr>
    10691217               <tr>
    … …  
    10731221               <tr>
    10741222                  <td class="left">Transfer-Encoding</td>
    1075                   <td class="left"><a href="p1-messaging.html#header.transfer-encoding" title="Transfer-Encoding">Section 3.3.1</a> of <a href="#Part1" id="rfc.xref.Part1.9"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a></td>
     1223                  <td class="left"><a href="p1-messaging.html#header.transfer-encoding" title="Transfer-Encoding">Section 3.3.1</a> of <a href="#Part1" id="rfc.xref.Part1.13"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a></td>
    10761224               </tr>
    10771225            </tbody>
    10781226         </table>
    10791227      </div>
    1080       <h3 id="rfc.section.3.3.2"><a href="#rfc.section.3.3.2">3.3.2</a>&nbsp;<a id="identifying.payload" href="#identifying.payload">Identifying the Payload</a></h3>
    1081       <p id="rfc.section.3.3.2.p.1">When a complete or partial representation is transferred in a message payload, it is often desirable for the sender to supply,
    1082          or the recipient to determine, an identifier for the resource corresponding to that representation.
    1083       </p>
    1084       <p id="rfc.section.3.3.2.p.2">The following rules are used to determine such a URI for the payload of a request message: </p>
    1085       <ul>
    1086          <li>If the request has a <a href="#header.content-location" class="smpl">Content-Location</a> header field, then the sender asserts that the payload is a representation of the resource identified by the Content-Location
    1087             field-value. However, such an assertion cannot be trusted unless it can be verified by other means (not defined by HTTP).
    1088             The information might still be useful for revision history links.
    1089          </li>
    1090          <li>Otherwise, the payload is unidentified.</li>
    1091       </ul>
    1092       <p id="rfc.section.3.3.2.p.3">The following rules, to be applied in order until a match is found, are used to determine such a URI for the payload of a
    1093          response message:
    1094       </p>
    1095       <ol>
    1096          <li>If the request is GET or HEAD and the response status code is <a href="#status.200" class="smpl">200 (OK)</a>, <a href="#status.204" class="smpl">204 (No Content)</a>, <a href="p5-range.html#status.206" class="smpl">206 (Partial Content)</a>, or <a href="p4-conditional.html#status.304" class="smpl">304 (Not Modified)</a>, the payload's identifier is 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.Part1.10"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>).
    1097          </li>
    1098          <li>If the request is GET or HEAD and the response status code is <a href="#status.203" class="smpl">203 (Non-Authoritative Information)</a>, the payload is a potentially modified representation of the target resource; as such, the effective request URI might only
    1099             act as an identifier for the payload's representation when a request is made via the same chain of intermediaries.
    1100          </li>
    1101          <li>If the response has a <a href="#header.content-location" class="smpl">Content-Location</a> header field and its field-value is a reference to the same URI as the effective request URI, the payload's identifier is
    1102             the effective request URI.
    1103          </li>
    1104          <li>If the response has a <a href="#header.content-location" class="smpl">Content-Location</a> header field and its field-value is a reference to a URI different from the effective request URI, then the sender asserts
    1105             that the payload is a representation of the resource identified by the Content-Location field-value. However, such an assertion
    1106             cannot be trusted unless it can be verified by other means (not defined by HTTP).
    1107          </li>
    1108          <li>Otherwise, the payload is unidentified.</li>
    1109       </ol>
    11101228      <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>
    11111229      <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
    … …  
    11611279      </p>
    11621280      <p id="rfc.section.3.4.1.p.5">HTTP/1.1 includes the following header fields for enabling proactive 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;5.3.2</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;5.3.3</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;5.3.4</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;5.3.5</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;5.5.3</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
     1281         and user preferences: <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.2" 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.2" 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
    11641282         within extension header fields not defined by this specification.
    11651283      </p>
    … …  
    11681286         </p>
    11691287      </div>
    1170       <p id="rfc.section.3.4.1.p.7">The <a href="#header.vary" class="smpl">Vary</a> header field (<a href="#header.vary" id="rfc.xref.header.vary.1" title="Vary">Section&nbsp;7.2.1</a>) can be used to express the parameters the server uses to select a representation that is subject to proactive negotiation.
     1288      <p id="rfc.section.3.4.1.p.7">The <a href="#header.vary" class="smpl">Vary</a> header field (<a href="#header.vary" id="rfc.xref.header.vary.1" title="Vary">Section&nbsp;8.2.1</a>) can be used to express the parameters the server uses to select a representation that is subject to proactive negotiation.
    11711289      </p>
    11721290      <h3 id="rfc.section.3.4.2"><a href="#rfc.section.3.4.2">3.4.2</a>&nbsp;<a id="reactive.negotiation" href="#reactive.negotiation">Reactive Negotiation</a></h3>
    … …  
    11891307         proactive negotiation.
    11901308      </p>
    1191       <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="methods" href="#methods">Request Methods</a></h1>
    1192       <h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a>&nbsp;<a id="method.overview" href="#method.overview">Overview</a></h2>
    1193       <p id="rfc.section.4.1.p.1">The request method token is the primary source of request semantics; it indicates the purpose for which the client has made
    1194          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;5</a>) if those additional semantics do not conflict with the method.
    1195       </p>
    1196       <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>
    1197 </pre><p id="rfc.section.4.1.p.3">HTTP was originally designed to be usable as an interface to distributed object systems. The request method was envisioned
     1309      <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="product.tokens" href="#product.tokens">Product Tokens</a></h1>
     1310      <p id="rfc.section.4.p.1">Product tokens are used to allow communicating applications to identify themselves by software name and version. Most fields
     1311         using product tokens also allow sub-products which form a significant part of the application to be listed, separated by whitespace.
     1312         By convention, the products are listed in order of their significance for identifying the application.
     1313      </p>
     1314      <div id="rfc.figure.u.16"></div><pre class="inline"><span id="rfc.iref.g.15"></span><span id="rfc.iref.g.16"></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>]
     1315  <a href="#product.tokens" class="smpl">product-version</a> = <a href="#imported.abnf" class="smpl">token</a>
     1316</pre><p id="rfc.section.4.p.3">Examples:</p>
     1317      <div id="rfc.figure.u.17"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
     1318  Server: Apache/0.8.4
     1319</pre><p id="rfc.section.4.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).
     1320      </p>
     1321      <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="methods" href="#methods">Request Methods</a></h1>
     1322      <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a>&nbsp;<a id="method.overview" href="#method.overview">Overview</a></h2>
     1323      <p id="rfc.section.5.1.p.1">The request method token is the primary source of request semantics; it indicates the purpose for which the client has made
     1324         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.
     1325      </p>
     1326      <div id="rfc.figure.u.18"></div><pre class="inline"><span id="rfc.iref.g.17"></span>  <a href="#method.overview" class="smpl">method</a> = <a href="#imported.abnf" class="smpl">token</a>
     1327</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
    11981328         as applying semantics to a target resource in much the same way as invoking a defined method on an identified object would
    11991329         apply semantics. The method token is case-sensitive because it might be used as a gateway to object-based systems with case-sensitive
    12001330         method names.
    12011331      </p>
    1202       <p id="rfc.section.4.1.p.4">Unlike distributed objects, the standardized request methods in HTTP are not resource-specific, since uniform interfaces provide
     1332      <p id="rfc.section.5.1.p.4">Unlike distributed objects, the standardized request methods in HTTP are not resource-specific, since uniform interfaces provide
    12031333         for better visibility and reuse in network-based systems <a href="#REST" id="rfc.xref.REST.2"><cite title="Architectural Styles and the Design of Network-based Software Architectures">[REST]</cite></a>. Once defined, a standardized method <em class="bcp14">MUST</em> have the same semantics when applied to any resource, though each resource determines for itself whether those semantics are
    12041334         implemented or allowed.
    12051335      </p>
    1206       <p id="rfc.section.4.1.p.5">This specification defines a number of standardized methods that are commonly used in HTTP, as outlined by the following table.
     1336      <p id="rfc.section.5.1.p.5">This specification defines a number of standardized methods that are commonly used in HTTP, as outlined by the following table.
    12071337         By convention, standardized methods are defined in all-uppercase ASCII letters.
    12081338      </p>
    … …  
    12211351                  <td class="left">GET</td>
    12221352                  <td class="left">Transfer a current representation of the target resource.</td>
    1223                   <td class="left"><a href="#GET" id="rfc.xref.GET.2" title="GET">4.3.1</a></td>
     1353                  <td class="left"><a href="#GET" id="rfc.xref.GET.2" title="GET">5.3.1</a></td>
    12241354               </tr>
    12251355               <tr>
    12261356                  <td class="left">HEAD</td>
    12271357                  <td class="left">Same as GET, but do not include a message body in the response.</td>
    1228                   <td class="left"><a href="#HEAD" id="rfc.xref.HEAD.1" title="HEAD">4.3.2</a></td>
     1358                  <td class="left"><a href="#HEAD" id="rfc.xref.HEAD.1" title="HEAD">5.3.2</a></td>
    12291359               </tr>
    12301360               <tr>
    12311361                  <td class="left">POST</td>
    12321362                  <td class="left">Perform resource-specific processing on the request payload.</td>
    1233                   <td class="left"><a href="#POST" id="rfc.xref.POST.2" title="POST">4.3.3</a></td>
     1363                  <td class="left"><a href="#POST" id="rfc.xref.POST.2" title="POST">5.3.3</a></td>
    12341364               </tr>
    12351365               <tr>
    12361366                  <td class="left">PUT</td>
    12371367                  <td class="left">Replace all current representations of the target resource with the request payload.</td>
    1238                   <td class="left"><a href="#PUT" id="rfc.xref.PUT.2" title="PUT">4.3.4</a></td>
     1368                  <td class="left"><a href="#PUT" id="rfc.xref.PUT.2" title="PUT">5.3.4</a></td>
    12391369               </tr>
    12401370               <tr>
    12411371                  <td class="left">DELETE</td>
    12421372                  <td class="left">Remove all current representations of the target resource.</td>
    1243                   <td class="left"><a href="#DELETE" id="rfc.xref.DELETE.1" title="DELETE">4.3.5</a></td>
     1373                  <td class="left"><a href="#DELETE" id="rfc.xref.DELETE.1" title="DELETE">5.3.5</a></td>
    12441374               </tr>
    12451375               <tr>
    12461376                  <td class="left">CONNECT</td>
    12471377                  <td class="left">Establish a tunnel to the server identified by the target resource.</td>
    1248                   <td class="left"><a href="#CONNECT" id="rfc.xref.CONNECT.1" title="CONNECT">4.3.6</a></td>
     1378                  <td class="left"><a href="#CONNECT" id="rfc.xref.CONNECT.1" title="CONNECT">5.3.6</a></td>
    12491379               </tr>
    12501380               <tr>
    12511381                  <td class="left">OPTIONS</td>
    12521382                  <td class="left">Describe the communication options for the target resource.</td>
    1253                   <td class="left"><a href="#OPTIONS" id="rfc.xref.OPTIONS.1" title="OPTIONS">4.3.7</a></td>
     1383                  <td class="left"><a href="#OPTIONS" id="rfc.xref.OPTIONS.1" title="OPTIONS">5.3.7</a></td>
    12541384               </tr>
    12551385               <tr>
    12561386                  <td class="left">TRACE</td>
    12571387                  <td class="left">Perform a message loop-back test along the path to the target resource.</td>
    1258                   <td class="left"><a href="#TRACE" id="rfc.xref.TRACE.1" title="TRACE">4.3.8</a></td>
     1388                  <td class="left"><a href="#TRACE" id="rfc.xref.TRACE.1" title="TRACE">5.3.8</a></td>
    12591389               </tr>
    12601390            </tbody>
    12611391         </table>
    12621392      </div>
    1263       <p id="rfc.section.4.1.p.6">The methods GET and HEAD <em class="bcp14">MUST</em> be supported by all general-purpose servers. All other methods are <em class="bcp14">OPTIONAL</em>. When implemented, a server <em class="bcp14">MUST</em> implement the above methods according to the semantics defined for them in <a href="#method.definitions" title="Method Definitions">Section&nbsp;4.3</a>.
    1264       </p>
    1265       <p id="rfc.section.4.1.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
     1393      <p id="rfc.section.5.1.p.6">The methods GET and HEAD <em class="bcp14">MUST</em> be supported by all general-purpose servers. All other methods are <em class="bcp14">OPTIONAL</em>. When implemented, a server <em class="bcp14">MUST</em> implement the above methods according to the semantics defined for them in <a href="#method.definitions" title="Method Definitions">Section&nbsp;5.3</a>.
     1394      </p>
     1395      <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
    12661396         Method Registry maintained by IANA, as defined in <a href="#method.registry" title="Method Registry">Section&nbsp;9.1</a>.
    12671397      </p>
    1268       <p id="rfc.section.4.1.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;7.4.1</a>). However, the set of allowed methods can change dynamically. When a request message is received that is unrecognized or
     1398      <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
    12691399         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,
    12701400         the origin server <em class="bcp14">SHOULD</em> respond with the <a href="#status.405" class="smpl">405 (Method Not Allowed)</a> status code.
    12711401      </p>
    1272       <h2 id="rfc.section.4.2"><a href="#rfc.section.4.2">4.2</a>&nbsp;<a id="method.properties" href="#method.properties">Common Method Properties</a></h2>
     1402      <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</a>&nbsp;<a id="method.properties" href="#method.properties">Common Method Properties</a></h2>
    12731403      <div id="rfc.iref.s.1"></div>
    1274       <h3 id="rfc.section.4.2.1"><a href="#rfc.section.4.2.1">4.2.1</a>&nbsp;<a id="safe.methods" href="#safe.methods">Safe Methods</a></h3>
    1275       <p id="rfc.section.4.2.1.p.1">Request methods are considered "<dfn id="safe">safe</dfn>" if their defined semantics are essentially read-only; i.e., the client does not request, and does not expect, any state
     1404      <h3 id="rfc.section.5.2.1"><a href="#rfc.section.5.2.1">5.2.1</a>&nbsp;<a id="safe.methods" href="#safe.methods">Safe Methods</a></h3>
     1405      <p id="rfc.section.5.2.1.p.1">Request methods are considered "<dfn id="safe">safe</dfn>" if their defined semantics are essentially read-only; i.e., the client does not request, and does not expect, any state
    12761406         change on the origin server as a result of applying a safe method to a target resource. Likewise, reasonable use of a safe
    12771407         method is not expected to cause any harm, loss of property, or unusual burden on the origin server.
    12781408      </p>
    1279       <p id="rfc.section.4.2.1.p.2">This definition of safe methods does not prevent an implementation from including behavior that is potentially harmful, not
     1409      <p id="rfc.section.5.2.1.p.2">This definition of safe methods does not prevent an implementation from including behavior that is potentially harmful, not
    12801410         entirely read-only, or which causes side-effects while invoking a safe method. What is important, however, is that the client
    12811411         did not request that additional behavior and cannot be held accountable for it. For example, most servers append request information
    … …  
    12841414         the Web will often have the side-effect of charging an advertising account.
    12851415      </p>
    1286       <p id="rfc.section.4.2.1.p.3">The GET, HEAD, OPTIONS, and TRACE request methods are defined to be safe.</p>
    1287       <p id="rfc.section.4.2.1.p.4">The purpose of distinguishing between safe and unsafe methods is to allow automated retrieval processes (spiders) and cache
     1416      <p id="rfc.section.5.2.1.p.3">The GET, HEAD, OPTIONS, and TRACE request methods are defined to be safe.</p>
     1417      <p id="rfc.section.5.2.1.p.4">The purpose of distinguishing between safe and unsafe methods is to allow automated retrieval processes (spiders) and cache
    12881418         performance optimization (pre-fetching) to work without fear of causing harm. In addition, it allows a user agent to apply
    12891419         appropriate constraints on the automated use of unsafe methods when processing potentially untrusted content.
    12901420      </p>
    1291       <p id="rfc.section.4.2.1.p.5">A user agent <em class="bcp14">SHOULD</em> distinguish between safe and unsafe methods when presenting potential actions to a user, such that the user can be made aware
     1421      <p id="rfc.section.5.2.1.p.5">A user agent <em class="bcp14">SHOULD</em> distinguish between safe and unsafe methods when presenting potential actions to a user, such that the user can be made aware
    12921422         of an unsafe action before it is requested.
    12931423      </p>
    1294       <p id="rfc.section.4.2.1.p.6">When a resource is constructed such that parameters within the effective request URI have the effect of selecting an action,
     1424      <p id="rfc.section.5.2.1.p.6">When a resource is constructed such that parameters within the effective request URI have the effect of selecting an action,
    12951425         it is the resource owner's responsibility to ensure that the action is consistent with the request method semantics. For example,
    12961426         it is common for Web-based content editing software to use actions within query parameters, such as "page?do=delete". If the
    … …  
    13001430      </p>
    13011431      <div id="rfc.iref.i.1"></div>
    1302       <h3 id="rfc.section.4.2.2"><a href="#rfc.section.4.2.2">4.2.2</a>&nbsp;<a id="idempotent.methods" href="#idempotent.methods">Idempotent Methods</a></h3>
    1303       <p id="rfc.section.4.2.2.p.1">Request methods are considered "<dfn id="idempotent">idempotent</dfn>" if the intended effect of multiple identical requests is the same as for a single request. PUT, DELETE, and all safe request
     1432      <h3 id="rfc.section.5.2.2"><a href="#rfc.section.5.2.2">5.2.2</a>&nbsp;<a id="idempotent.methods" href="#idempotent.methods">Idempotent Methods</a></h3>
     1433      <p id="rfc.section.5.2.2.p.1">Request methods are considered "<dfn id="idempotent">idempotent</dfn>" if the intended effect of multiple identical requests is the same as for a single request. PUT, DELETE, and all safe request
    13041434         methods are idempotent.
    13051435      </p>
    1306       <p id="rfc.section.4.2.2.p.2">Like the definition of safe, the idempotent property only applies to what has been requested by the user; a server is free
     1436      <p id="rfc.section.5.2.2.p.2">Like the definition of safe, the idempotent property only applies to what has been requested by the user; a server is free
    13071437         to log each request separately, retain a revision control history, or implement other non-idempotent side-effects for each
    13081438         idempotent request.
    13091439      </p>
    1310       <p id="rfc.section.4.2.2.p.3">Idempotent methods are distinguished because the request can be repeated automatically if a communication failure occurs before
     1440      <p id="rfc.section.5.2.2.p.3">Idempotent methods are distinguished because the request can be repeated automatically if a communication failure occurs before
    13111441         the client is able to read the server's response. For example, if a client sends a PUT request and the underlying connection
    13121442         is closed before any response is received, then it can establish a new connection and retry the idempotent request because
    … …  
    13141444         repeated failures would indicate a problem within the server.
    13151445      </p>
    1316       <div id="rfc.iref.c.6"></div>
    1317       <h3 id="rfc.section.4.2.3"><a href="#rfc.section.4.2.3">4.2.3</a>&nbsp;<a id="cacheable.methods" href="#cacheable.methods">Cacheable Methods</a></h3>
    1318       <p id="rfc.section.4.2.3.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
     1446      <div id="rfc.iref.c.7"></div>
     1447      <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>
     1448      <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
    13191449         are defined to be cacheable. In general, safe methods that do not depend on a current or authoritative response are cacheable,
    13201450         though the overwhelming majority of caches only support GET and HEAD. HTTP requirements for cache behavior and cacheable responses
    13211451         are defined in <a href="#Part6" id="rfc.xref.Part6.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>.
    13221452      </p>
    1323       <h2 id="rfc.section.4.3"><a href="#rfc.section.4.3">4.3</a>&nbsp;<a id="method.definitions" href="#method.definitions">Method Definitions</a></h2>
    1324       <h3 id="rfc.section.4.3.1"><a href="#rfc.section.4.3.1">4.3.1</a>&nbsp;<a id="GET" href="#GET">GET</a></h3>
    1325       <div id="rfc.iref.g.6"></div>
    1326       <p id="rfc.section.4.3.1.p.1">The GET method requests transfer of a current representation of the target resource.</p>
    1327       <p id="rfc.section.4.3.1.p.2">If the target resource is a data-producing process, it is the produced data which shall be returned as the representation
     1453      <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>
     1454      <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>
     1455      <div id="rfc.iref.g.18"></div>
     1456      <p id="rfc.section.5.3.1.p.1">The GET method requests transfer of a current representation of the target resource.</p>
     1457      <p id="rfc.section.5.3.1.p.2">If the target resource is a data-producing process, it is the produced data which shall be returned as the representation
    13281458         in the response and not the source text of the process, unless that text happens to be the output of the process.
    13291459      </p>
    1330       <p id="rfc.section.4.3.1.p.3">The semantics of the GET method change to a "conditional GET" if the request message includes an <a href="p4-conditional.html#header.if-modified-since" class="smpl">If-Modified-Since</a>, <a href="p4-conditional.html#header.if-unmodified-since" class="smpl">If-Unmodified-Since</a>, <a href="p4-conditional.html#header.if-match" class="smpl">If-Match</a>, <a href="p4-conditional.html#header.if-none-match" class="smpl">If-None-Match</a>, or <a href="p5-range.html#header.if-range" class="smpl">If-Range</a> header field (<a href="#Part4" id="rfc.xref.Part4.1"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a>). A conditional GET requests that the representation be transferred only under the circumstances described by the conditional
     1460      <p id="rfc.section.5.3.1.p.3">The semantics of the GET method change to a "conditional GET" if the request message includes an <a href="p4-conditional.html#header.if-modified-since" class="smpl">If-Modified-Since</a>, <a href="p4-conditional.html#header.if-unmodified-since" class="smpl">If-Unmodified-Since</a>, <a href="p4-conditional.html#header.if-match" class="smpl">If-Match</a>, <a href="p4-conditional.html#header.if-none-match" class="smpl">If-None-Match</a>, or <a href="p5-range.html#header.if-range" class="smpl">If-Range</a> header field (<a href="#Part4" id="rfc.xref.Part4.1"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a>). A conditional GET requests that the representation be transferred only under the circumstances described by the conditional
    13311461         header field(s). The conditional GET request is intended to reduce unnecessary network usage by allowing cached representations
    13321462         to be refreshed without requiring multiple requests or transferring data already held by the client.
    13331463      </p>
    1334       <p id="rfc.section.4.3.1.p.4">The semantics of the GET method change to a "partial GET" if the request message includes a <a href="p5-range.html#range.retrieval.requests" class="smpl">Range</a> header field (<a href="#Part5" id="rfc.xref.Part5.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a>). A partial GET requests that only part of the representation be transferred, as described in <a href="p5-range.html#header.range" title="Range">Section 5.4</a> of <a href="#Part5" id="rfc.xref.Part5.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a>. The partial GET request is intended to reduce unnecessary network usage by allowing partially-retrieved representations
     1464      <p id="rfc.section.5.3.1.p.4">The semantics of the GET method change to a "partial GET" if the request message includes a <a href="p5-range.html#range.retrieval.requests" class="smpl">Range</a> header field (<a href="#Part5" id="rfc.xref.Part5.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a>). A partial GET requests that only part of the representation be transferred, as described in <a href="p5-range.html#header.range" title="Range">Section 5.4</a> of <a href="#Part5" id="rfc.xref.Part5.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a>. The partial GET request is intended to reduce unnecessary network usage by allowing partially-retrieved representations
    13351465         to be completed without transferring data already held by the client.
    13361466      </p>
    1337       <p id="rfc.section.4.3.1.p.5">A payload within a GET request message has no defined semantics; sending a payload body on a GET request might cause some
     1467      <p id="rfc.section.5.3.1.p.5">A payload within a GET request message has no defined semantics; sending a payload body on a GET request might cause some
    13381468         existing implementations to reject the request.
    13391469      </p>
    1340       <p id="rfc.section.4.3.1.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.Part6.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>).
    1341       </p>
    1342       <p id="rfc.section.4.3.1.p.7">See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section&nbsp;10.2</a> for security considerations when used for forms.
    1343       </p>
    1344       <h3 id="rfc.section.4.3.2"><a href="#rfc.section.4.3.2">4.3.2</a>&nbsp;<a id="HEAD" href="#HEAD">HEAD</a></h3>
     1470      <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.Part6.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>).
     1471      </p>
     1472      <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;10.2</a> for security considerations when used for forms.
     1473      </p>
     1474      <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>
    13451475      <div id="rfc.iref.h.1"></div>
    1346       <p id="rfc.section.4.3.2.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
     1476      <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
    13471477         representation implied by the request without transferring the representation data. This method is often used for testing
    13481478         hypertext links for validity, accessibility, and recent modification.
    13491479      </p>
    1350       <p id="rfc.section.4.3.2.p.2">The response to a HEAD request is cacheable and <em class="bcp14">MAY</em> be used to satisfy a subsequent HEAD request. It also has potential side effects on previously stored responses to GET; see <a href="p6-cache.html#head.effects" title="Updating Caches with HEAD Responses">Section 5</a> of <a href="#Part6" id="rfc.xref.Part6.4"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>.
    1351       </p>
    1352       <p id="rfc.section.4.3.2.p.3">A payload within a HEAD request message has no defined semantics; sending a payload body on a HEAD request might cause some
     1480      <p id="rfc.section.5.3.2.p.2">The response to a HEAD request is cacheable and <em class="bcp14">MAY</em> be used to satisfy a subsequent HEAD request. It also has potential side effects on previously stored responses to GET; see <a href="p6-cache.html#head.effects" title="Updating Caches with HEAD Responses">Section 5</a> of <a href="#Part6" id="rfc.xref.Part6.4"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>.
     1481      </p>
     1482      <p id="rfc.section.5.3.2.p.3">A payload within a HEAD request message has no defined semantics; sending a payload body on a HEAD request might cause some
    13531483         existing implementations to reject the request.
    13541484      </p>
    13551485      <div id="rfc.iref.p.2"></div>
    1356       <h3 id="rfc.section.4.3.3"><a href="#rfc.section.4.3.3">4.3.3</a>&nbsp;<a id="POST" href="#POST">POST</a></h3>
    1357       <p id="rfc.section.4.3.3.p.1">The POST method requests that the origin server accept the representation enclosed in the request as data to be processed
     1486      <h3 id="rfc.section.5.3.3"><a href="#rfc.section.5.3.3">5.3.3</a>&nbsp;<a id="POST" href="#POST">POST</a></h3>
     1487      <p id="rfc.section.5.3.3.p.1">The POST method requests that the origin server accept the representation enclosed in the request as data to be processed
    13581488         by the target resource. POST is designed to allow a uniform method to cover the following functions:
    13591489      </p>
    … …  
    13641494         <li>Extending a database through an append operation.</li>
    13651495      </ul>
    1366       <p id="rfc.section.4.3.3.p.2">The actual function performed by the POST method is determined by the server and is usually dependent on the effective request
     1496      <p id="rfc.section.5.3.3.p.2">The actual function performed by the POST method is determined by the server and is usually dependent on the effective request
    13671497         URI.
    13681498      </p>
    1369       <p id="rfc.section.4.3.3.p.3">The action performed by the POST method might not result in a resource that can be identified by a URI. In this case, either <a href="#status.200" class="smpl">200 (OK)</a> or <a href="#status.204" class="smpl">204 (No Content)</a> is the appropriate response status code, depending on whether or not the response includes a representation that describes
     1499      <p id="rfc.section.5.3.3.p.3">The action performed by the POST method might not result in a resource that can be identified by a URI. In this case, either <a href="#status.200" class="smpl">200 (OK)</a> or <a href="#status.204" class="smpl">204 (No Content)</a> is the appropriate response status code, depending on whether or not the response includes a representation that describes
    13701500         the result.
    13711501      </p>
    1372       <p id="rfc.section.4.3.3.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;7.1.2</a>).
    1373       </p>
    1374       <p id="rfc.section.4.3.3.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.Part6.5"><cite title="Hypertext Transfer Protocol (HTTP/1.1): 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;3.1.4</a>) whose value is the effective Request URI <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD (not POST) requests.
    1375       </p>
    1376       <p id="rfc.section.4.3.3.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.
    1377       </p>
    1378       <h3 id="rfc.section.4.3.4"><a href="#rfc.section.4.3.4">4.3.4</a>&nbsp;<a id="PUT" href="#PUT">PUT</a></h3>
     1502      <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;8.1.2</a>).
     1503      </p>
     1504      <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.Part6.5"><cite title="Hypertext Transfer Protocol (HTTP/1.1): 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;3.1.4.2</a>) whose value is the effective Request URI <em class="bcp14">MAY</em> be used to satisfy subsequent GET and HEAD (not POST) requests.
     1505      </p>
     1506      <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.
     1507      </p>
     1508      <h3 id="rfc.section.5.3.4"><a href="#rfc.section.5.3.4">5.3.4</a>&nbsp;<a id="PUT" href="#PUT">PUT</a></h3>
    13791509      <div id="rfc.iref.p.3"></div>
    1380       <p id="rfc.section.4.3.4.p.1">The PUT method requests that the state of the target resource be created or replaced with the state defined by the representation
     1510      <p id="rfc.section.5.3.4.p.1">The PUT method requests that the state of the target resource be created or replaced with the state defined by the representation
    13811511         enclosed in the request message payload. A successful PUT of a given representation would suggest that a subsequent GET on
    13821512         that same target resource will result in an equivalent representation being returned in a <a href="#status.200" class="smpl">200 (OK)</a> response. However, there is no guarantee that such a state change will be observable, since the target resource might be acted
    … …  
    13851515         by the origin server.
    13861516      </p>
    1387       <p id="rfc.section.4.3.4.p.2">If the target resource does not have a current representation and the PUT successfully creates one, then the origin server <em class="bcp14">MUST</em> inform the user agent by sending a <a href="#status.201" class="smpl">201 (Created)</a> response. If the target resource does have a current representation and that representation is successfully modified in accordance
     1517      <p id="rfc.section.5.3.4.p.2">If the target resource does not have a current representation and the PUT successfully creates one, then the origin server <em class="bcp14">MUST</em> inform the user agent by sending a <a href="#status.201" class="smpl">201 (Created)</a> response. If the target resource does have a current representation and that representation is successfully modified in accordance
    13881518         with the state of the enclosed representation, then either a <a href="#status.200" class="smpl">200 (OK)</a> or <a href="#status.204" class="smpl">204 (No Content)</a> response <em class="bcp14">SHOULD</em> be sent to indicate successful completion of the request.
    13891519      </p>
    1390       <p id="rfc.section.4.3.4.p.3">Unrecognized header fields <em class="bcp14">SHOULD</em> be ignored (i.e., not saved as part of the resource state).
    1391       </p>
    1392       <p id="rfc.section.4.3.4.p.4">An origin server <em class="bcp14">SHOULD</em> verify that the PUT representation is consistent with any constraints which the server has for the target resource that cannot
     1520      <p id="rfc.section.5.3.4.p.3">Unrecognized header fields <em class="bcp14">SHOULD</em> be ignored (i.e., not saved as part of the resource state).
     1521      </p>
     1522      <p id="rfc.section.5.3.4.p.4">An origin server <em class="bcp14">SHOULD</em> verify that the PUT representation is consistent with any constraints which the server has for the target resource that cannot
    13931523         or will not be changed by the PUT. This is particularly important when the origin server uses internal configuration information
    13941524         related to the URI in order to set the values for representation metadata on GET responses. When a PUT representation is inconsistent
    … …  
    13961526         appropriate error message containing sufficient information to explain why the representation is unsuitable. The <a href="#status.409" class="smpl">409 (Conflict)</a> or <a href="#status.415" class="smpl">415 (Unsupported Media Type)</a> status codes are suggested, with the latter being specific to constraints on <a href="#header.content-type" class="smpl">Content-Type</a> values.
    13971527      </p>
    1398       <p id="rfc.section.4.3.4.p.5">For example, if the target resource is configured to always have a <a href="#header.content-type" class="smpl">Content-Type</a> of "text/html" and the representation being PUT has a Content-Type of "image/jpeg", then the origin server <em class="bcp14">SHOULD</em> do one of:
     1528      <p id="rfc.section.5.3.4.p.5">For example, if the target resource is configured to always have a <a href="#header.content-type" class="smpl">Content-Type</a> of "text/html" and the representation being PUT has a Content-Type of "image/jpeg", then the origin server <em class="bcp14">SHOULD</em> do one of:
    13991529      </p>
    14001530      <ol class="la">
    … …  
    14071537         </li>
    14081538      </ol>
    1409       <p id="rfc.section.4.3.4.p.6">HTTP does not define exactly how a PUT method affects the state of an origin server beyond what can be expressed by the intent
     1539      <p id="rfc.section.5.3.4.p.6">HTTP does not define exactly how a PUT method affects the state of an origin server beyond what can be expressed by the intent
    14101540         of the user agent request and the semantics of the origin server response. It does not define what a resource might be, in
    14111541         any sense of that word, beyond the interface provided via HTTP. It does not define how resource state is "stored", nor how
    … …  
    14141544         the server.
    14151545      </p>
    1416       <p id="rfc.section.4.3.4.p.7">The fundamental difference between the POST and PUT methods is highlighted by the different intent for the target resource.
     1546      <p id="rfc.section.5.3.4.p.7">The fundamental difference between the POST and PUT methods is highlighted by the different intent for the target resource.
    14171547         The target resource in a POST request is intended to handle the enclosed representation as a data-accepting process, such
    14181548         as for a gateway to some other protocol or a document that accepts annotations. In contrast, the target resource in a PUT
    … …  
    14201550         and visible to intermediaries, even though the exact effect is only known by the origin server.
    14211551      </p>
    1422       <p id="rfc.section.4.3.4.p.8">Proper interpretation of a PUT request presumes that the user agent knows what target resource is desired. A service that
     1552      <p id="rfc.section.5.3.4.p.8">Proper interpretation of a PUT request presumes that the user agent knows what target resource is desired. A service that
    14231553         is intended to select a proper URI on behalf of the client, after receiving a state-changing request, <em class="bcp14">SHOULD</em> be implemented using the POST method rather than PUT. If the origin server will not make the requested PUT state change to
    14241554         the target resource and instead wishes to have it applied to a different resource, such as when the resource has been moved
    14251555         to a different URI, then the origin server <em class="bcp14">MUST</em> send a <a href="#status.301" class="smpl">301 (Moved Permanently)</a> response; the user agent <em class="bcp14">MAY</em> then make its own decision regarding whether or not to redirect the request.
    14261556      </p>
    1427       <p id="rfc.section.4.3.4.p.9">A PUT request applied to the target resource <em class="bcp14">MAY</em> have side-effects on other resources. For example, an article might have a URI for identifying "the current version" (a resource)
     1557      <p id="rfc.section.5.3.4.p.9">A PUT request applied to the target resource <em class="bcp14">MAY</em> have side-effects on other resources. For example, an article might have a URI for identifying "the current version" (a resource)
    14281558         which is separate from the URIs identifying each particular version (different resources that at one point shared the same
    14291559         state as the current version resource). A successful PUT request on "the current version" URI might therefore create a new
    … …  
    14311561         the related resources.
    14321562      </p>
    1433       <p id="rfc.section.4.3.4.p.10">An origin server <em class="bcp14">SHOULD</em> reject any PUT request that contains a <a href="p5-range.html#header.content-range" class="smpl">Content-Range</a> header field (<a href="p5-range.html#header.content-range" title="Content-Range">Section 5.2</a> of <a href="#Part5" id="rfc.xref.Part5.4"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a>), since it might be misinterpreted as partial content (or might be partial content that is being mistakenly PUT as a full
     1563      <p id="rfc.section.5.3.4.p.10">An origin server <em class="bcp14">SHOULD</em> reject any PUT request that contains a <a href="p5-range.html#header.content-range" class="smpl">Content-Range</a> header field (<a href="p5-range.html#header.content-range" title="Content-Range">Section 5.2</a> of <a href="#Part5" id="rfc.xref.Part5.4"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a>), since it might be misinterpreted as partial content (or might be partial content that is being mistakenly PUT as a full
    14341564         representation). Partial content updates are possible by targeting a separately identified resource with state that overlaps
    14351565         a portion of the larger resource, or by using a different method that has been specifically defined for partial updates (for
    14361566         example, the PATCH method defined in <a href="#RFC5789" id="rfc.xref.RFC5789.1"><cite title="PATCH Method for HTTP">[RFC5789]</cite></a>).
    14371567      </p>
    1438       <p id="rfc.section.4.3.4.p.11">Responses to the PUT method are not cacheable. If a PUT request passes through a cache that has one or more stored responses
     1568      <p id="rfc.section.5.3.4.p.11">Responses to the PUT method are not cacheable. If a PUT request passes through a cache that has one or more stored responses
    14391569         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.Part6.6"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>).
    14401570      </p>
    1441       <h3 id="rfc.section.4.3.5"><a href="#rfc.section.4.3.5">4.3.5</a>&nbsp;<a id="DELETE" href="#DELETE">DELETE</a></h3>
    1442       <div id="rfc.iref.d.1"></div>
    1443       <p id="rfc.section.4.3.5.p.1">The DELETE method requests that the origin server delete the target resource. This method <em class="bcp14">MAY</em> be overridden by human intervention (or other means) on the origin server. The client cannot be guaranteed that the operation
     1571      <h3 id="rfc.section.5.3.5"><a href="#rfc.section.5.3.5">5.3.5</a>&nbsp;<a id="DELETE" href="#DELETE">DELETE</a></h3>
     1572      <div id="rfc.iref.d.2"></div>
     1573      <p id="rfc.section.5.3.5.p.1">The DELETE method requests that the origin server delete the target resource. This method <em class="bcp14">MAY</em> be overridden by human intervention (or other means) on the origin server. The client cannot be guaranteed that the operation
    14441574         has been carried out, even if the status code returned from the origin server indicates that the action has been completed
    14451575         successfully. However, the server <em class="bcp14">SHOULD NOT</em> indicate success unless, at the time the response is given, it intends to delete the resource or move it to an inaccessible
    14461576         location.
    14471577      </p>
    1448       <p id="rfc.section.4.3.5.p.2">A successful response <em class="bcp14">SHOULD</em> be <a href="#status.200" class="smpl">200 (OK)</a> if the response includes a representation describing the status, <a href="#status.202" class="smpl">202 (Accepted)</a> if the action has not yet been enacted, or <a href="#status.204" class="smpl">204 (No Content)</a> if the action has been enacted but the response does not include a representation.
    1449       </p>
    1450       <p id="rfc.section.4.3.5.p.3">A payload within a DELETE request message has no defined semantics; sending a payload body on a DELETE request might cause
     1578      <p id="rfc.section.5.3.5.p.2">A successful response <em class="bcp14">SHOULD</em> be <a href="#status.200" class="smpl">200 (OK)</a> if the response includes a representation describing the status, <a href="#status.202" class="smpl">202 (Accepted)</a> if the action has not yet been enacted, or <a href="#status.204" class="smpl">204 (No Content)</a> if the action has been enacted but the response does not include a representation.
     1579      </p>
     1580      <p id="rfc.section.5.3.5.p.3">A payload within a DELETE request message has no defined semantics; sending a payload body on a DELETE request might cause
    14511581         some existing implementations to reject the request.
    14521582      </p>
    1453       <p id="rfc.section.4.3.5.p.4">Responses to the DELETE method are not cacheable. If a DELETE request passes through a cache that has one or more stored responses
     1583      <p id="rfc.section.5.3.5.p.4">Responses to the DELETE method are not cacheable. If a DELETE request passes through a cache that has one or more stored responses
    14541584         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.Part6.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>).
    14551585      </p>
    1456       <div id="rfc.iref.c.7"></div>
    1457       <h3 id="rfc.section.4.3.6"><a href="#rfc.section.4.3.6">4.3.6</a>&nbsp;<a id="CONNECT" href="#CONNECT">CONNECT</a></h3>
    1458       <p id="rfc.section.4.3.6.p.1">The CONNECT method requests that the proxy establish a tunnel to the request-target and, if successful, thereafter restrict
     1586      <div id="rfc.iref.c.8"></div>
     1587      <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>
     1588      <p id="rfc.section.5.3.6.p.1">The CONNECT method requests that the proxy establish a tunnel to the request-target and, if successful, thereafter restrict
    14591589         its behavior to blind forwarding of packets until the connection is closed.
    14601590      </p>
    1461       <p id="rfc.section.4.3.6.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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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.
     1591      <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.Part1.14"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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.
    14621592         For example,
    14631593      </p>
    1464       <div id="rfc.figure.u.11"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
     1594      <div id="rfc.figure.u.19"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
    14651595Host: server.example.com:80
    14661596
    1467 </pre><p id="rfc.section.4.3.6.p.4">Any <a href="#status.2xx" class="smpl">2xx (Successful)</a> response to a CONNECT request indicates that the proxy has established a connection to the requested host and port, and has
     1597</pre><p id="rfc.section.5.3.6.p.4">Any <a href="#status.2xx" class="smpl">2xx (Successful)</a> response to a CONNECT request indicates that the proxy has established a connection to the requested host and port, and has
    14681598         switched to tunneling the current connection to that server connection. The tunneled data from the server begins immediately
    14691599         after the blank line that concludes the successful response's header block.
    14701600      </p>
    1471       <p id="rfc.section.4.3.6.p.5">A server <em class="bcp14">SHOULD NOT</em> send any <a href="p1-messaging.html#header.transfer-encoding" class="smpl">Transfer-Encoding</a> or <a href="p1-messaging.html#header.content-length" class="smpl">Content-Length</a> header fields in a successful response. A client <em class="bcp14">MUST</em> ignore any Content-Length or Transfer-Encoding header fields received in a successful response.
    1472       </p>
    1473       <p id="rfc.section.4.3.6.p.6">Any response other than a successful response indicates that the tunnel has not yet been formed and that the connection remains
     1601      <p id="rfc.section.5.3.6.p.5">A server <em class="bcp14">SHOULD NOT</em> send any <a href="p1-messaging.html#header.transfer-encoding" class="smpl">Transfer-Encoding</a> or <a href="p1-messaging.html#header.content-length" class="smpl">Content-Length</a> header fields in a successful response. A client <em class="bcp14">MUST</em> ignore any Content-Length or Transfer-Encoding header fields received in a successful response.
     1602      </p>
     1603      <p id="rfc.section.5.3.6.p.6">Any response other than a successful response indicates that the tunnel has not yet been formed and that the connection remains
    14741604         governed by HTTP.
    14751605      </p>
    1476       <p id="rfc.section.4.3.6.p.7">Proxy authentication might be used to establish the authority to create a tunnel:</p>
    1477       <div id="rfc.figure.u.12"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
     1606      <p id="rfc.section.5.3.6.p.7">Proxy authentication might be used to establish the authority to create a tunnel:</p>
     1607      <div id="rfc.figure.u.20"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
    14781608Host: server.example.com:80
    14791609Proxy-Authorization: basic aGVsbG86d29ybGQ=
    14801610
    1481 </pre><p id="rfc.section.4.3.6.p.9">A payload within a CONNECT request message has no defined semantics; sending a payload body on a CONNECT request might cause
     1611</pre><p id="rfc.section.5.3.6.p.9">A payload within a CONNECT request message has no defined semantics; sending a payload body on a CONNECT request might cause
    14821612         some existing implementations to reject the request.
    14831613      </p>
    1484       <p id="rfc.section.4.3.6.p.10">Similar to a pipelined HTTP/1.1 request, data to be tunneled from client to server <em class="bcp14">MAY</em> be sent immediately after the request (before a response is received). The usual caveats also apply: data can be discarded
     1614      <p id="rfc.section.5.3.6.p.10">Similar to a pipelined HTTP/1.1 request, data to be tunneled from client to server <em class="bcp14">MAY</em> be sent immediately after the request (before a response is received). The usual caveats also apply: data can be discarded
    14851615         if the eventual response is negative, and the connection can be reset with no response if more than one TCP segment is outstanding.
    14861616      </p>
    1487       <p id="rfc.section.4.3.6.p.11">It might be the case that the proxy itself can only reach the requested origin server through another proxy. In this case,
     1617      <p id="rfc.section.5.3.6.p.11">It might be the case that the proxy itself can only reach the requested origin server through another proxy. In this case,
    14881618         the first proxy <em class="bcp14">SHOULD</em> make a CONNECT request of that next proxy, requesting a tunnel to the authority. A proxy <em class="bcp14">MUST NOT</em> respond with any <a href="#status.2xx" class="smpl">2xx</a> status code unless it has either a direct or tunnel connection established to the authority.
    14891619      </p>
    1490       <p id="rfc.section.4.3.6.p.12">If at any point either one of the peers gets disconnected, any outstanding data that came from that peer will be passed to
     1620      <p id="rfc.section.5.3.6.p.12">If at any point either one of the peers gets disconnected, any outstanding data that came from that peer will be passed to
    14911621         the other one, and after that also the other connection will be terminated by the proxy. If there is outstanding data to that
    14921622         peer undelivered, that data will be discarded.
    14931623      </p>
    1494       <p id="rfc.section.4.3.6.p.13">An origin server which receives a CONNECT request for itself <em class="bcp14">MAY</em> respond with a <a href="#status.2xx" class="smpl">2xx</a> status code to indicate that a connection is established. However, most origin servers do not implement CONNECT.
    1495       </p>
    1496       <h3 id="rfc.section.4.3.7"><a href="#rfc.section.4.3.7">4.3.7</a>&nbsp;<a id="OPTIONS" href="#OPTIONS">OPTIONS</a></h3>
     1624      <p id="rfc.section.5.3.6.p.13">An origin server which receives a CONNECT request for itself <em class="bcp14">MAY</em> respond with a <a href="#status.2xx" class="smpl">2xx</a> status code to indicate that a connection is established. However, most origin servers do not implement CONNECT.
     1625      </p>
     1626      <h3 id="rfc.section.5.3.7"><a href="#rfc.section.5.3.7">5.3.7</a>&nbsp;<a id="OPTIONS" href="#OPTIONS">OPTIONS</a></h3>
    14971627      <div id="rfc.iref.o.1"></div>
    1498       <p id="rfc.section.4.3.7.p.1">The OPTIONS method requests information about the communication options available on the request/response chain identified
     1628      <p id="rfc.section.5.3.7.p.1">The OPTIONS method requests information about the communication options available on the request/response chain identified
    14991629         by the effective request URI. This method allows a client to determine the options and/or requirements associated with a resource,
    15001630         or the capabilities of a server, without implying a resource action or initiating a resource retrieval.
    15011631      </p>
    1502       <p id="rfc.section.4.3.7.p.2">Responses to the OPTIONS method are not cacheable.</p>
    1503       <p id="rfc.section.4.3.7.p.3">If the OPTIONS request includes a payload, then the media type <em class="bcp14">MUST</em> be indicated by a <a href="#header.content-type" class="smpl">Content-Type</a> field. Although this specification does not define any use for such a body, future extensions to HTTP might use the OPTIONS
     1632      <p id="rfc.section.5.3.7.p.2">Responses to the OPTIONS method are not cacheable.</p>
     1633      <p id="rfc.section.5.3.7.p.3">If the OPTIONS request includes a payload, then the media type <em class="bcp14">MUST</em> be indicated by a <a href="#header.content-type" class="smpl">Content-Type</a> field. Although this specification does not define any use for such a body, future extensions to HTTP might use the OPTIONS
    15041634         body to make more detailed queries on the server.
    15051635      </p>
    1506       <p id="rfc.section.4.3.7.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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) is an asterisk ("*"), the OPTIONS request is intended to apply to the server in general rather than to a specific resource.
     1636      <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.Part1.15"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) is an asterisk ("*"), the OPTIONS request is intended to apply to the server in general rather than to a specific resource.
    15071637         Since a server's communication options typically depend on the resource, the "*" request is only useful as a "ping" or "no-op"
    15081638         type of method; it does nothing beyond allowing the client to test the capabilities of the server. For example, this can be
    15091639         used to test a proxy for HTTP/1.1 conformance (or lack thereof).
    15101640      </p>
    1511       <p id="rfc.section.4.3.7.p.5">If the request-target is not an asterisk, the OPTIONS request applies only to the options that are available when communicating
     1641      <p id="rfc.section.5.3.7.p.5">If the request-target is not an asterisk, the OPTIONS request applies only to the options that are available when communicating
    15121642         with that resource.
    15131643      </p>
    1514       <p id="rfc.section.4.3.7.p.6">A <a href="#status.200" class="smpl">200 (OK)</a> response <em class="bcp14">SHOULD</em> include any header fields that indicate optional features implemented by the server and applicable to that resource (e.g., <a href="#header.allow" class="smpl">Allow</a>), possibly including extensions not defined by this specification. The response payload, if any, <em class="bcp14">SHOULD</em> also include information about the communication options. The format for such a payload is not defined by this specification,
     1644      <p id="rfc.section.5.3.7.p.6">A <a href="#status.200" class="smpl">200 (OK)</a> response <em class="bcp14">SHOULD</em> include any header fields that indicate optional features implemented by the server and applicable to that resource (e.g., <a href="#header.allow" class="smpl">Allow</a>), possibly including extensions not defined by this specification. The response payload, if any, <em class="bcp14">SHOULD</em> also include information about the communication options. The format for such a payload is not defined by this specification,
    15151645         but might be defined by future extensions to HTTP. Content negotiation <em class="bcp14">MAY</em> be used to select the appropriate representation. If no payload 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".
    15161646      </p>
    1517       <p id="rfc.section.4.3.7.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;5.1.1</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.
    1518       </p>
    1519       <h3 id="rfc.section.4.3.8"><a href="#rfc.section.4.3.8">4.3.8</a>&nbsp;<a id="TRACE" href="#TRACE">TRACE</a></h3>
     1647      <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.
     1648      </p>
     1649      <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>
    15201650      <div id="rfc.iref.t.1"></div>
    1521       <p id="rfc.section.4.3.8.p.1">The TRACE method requests a remote, application-level 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;5.1.1</a>). A TRACE request <em class="bcp14">MUST NOT</em> include a message body.
    1522       </p>
    1523       <p id="rfc.section.4.3.8.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
    1524          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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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
     1651      <p id="rfc.section.5.3.8.p.1">The TRACE method requests a remote, application-level 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.
     1652      </p>
     1653      <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
     1654         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.Part1.16"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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
    15251655         messages in an infinite loop.
    15261656      </p>
    1527       <p id="rfc.section.4.3.8.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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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.
    1528       </p>
    1529       <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="request.header.fields" href="#request.header.fields">Request Header Fields</a></h1>
    1530       <p id="rfc.section.5.p.1">A client sends request header fields to provide more information about the request context, make the request conditional based
     1657      <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.Part1.17"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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.
     1658      </p>
     1659      <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>
     1660      <p id="rfc.section.6.p.1">A client sends request header fields to provide more information about the request context, make the request conditional based
    15311661         on the target resource state, suggest preferred formats for the response, supply authentication credentials, or modify the
    15321662         expected request processing. These fields act as request modifiers, similar to the parameters on a programming language method
    15331663         invocation.
    15341664      </p>
    1535       <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a>&nbsp;<a id="request.controls" href="#request.controls">Controls</a></h2>
    1536       <p id="rfc.section.5.1.p.1">Controls are request header fields that direct specific handling of the request.</p>
     1665      <h2 id="rfc.section.6.1"><a href="#rfc.section.6.1">6.1</a>&nbsp;<a id="request.controls" href="#request.controls">Controls</a></h2>
     1666      <p id="rfc.section.6.1.p.1">Controls are request header fields that direct specific handling of the request.</p>
    15371667      <div id="rfc.table.u.3">
    15381668         <table class="tt full left" cellpadding="3" cellspacing="0">
    … …  
    15461676               <tr>
    15471677                  <td class="left">Host</td>
    1548                   <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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a></td>
     1678                  <td class="left"><a href="p1-messaging.html#header.host" title="Host">Section 5.4</a> of <a href="#Part1" id="rfc.xref.Part1.18"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a></td>
    15491679               </tr>
    15501680               <tr>
    15511681                  <td class="left">Max-Forwards</td>
    1552                   <td class="left"><a href="#header.max-forwards" id="rfc.xref.header.max-forwards.3" title="Max-Forwards">Section&nbsp;5.1.1</a></td>
     1682                  <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>
    15531683               </tr>
    15541684               <tr>
    15551685                  <td class="left">Expect</td>
    1556                   <td class="left"><a href="#header.expect" id="rfc.xref.header.expect.1" title="Expect">Section&nbsp;5.1.2</a></td>
     1686                  <td class="left"><a href="#header.expect" id="rfc.xref.header.expect.1" title="Expect">Section&nbsp;6.1.2</a></td>
    15571687               </tr>
    15581688               <tr>
    … …  
    15641694      </div>
    15651695      <div id="rfc.iref.m.1"></div>
    1566       <h3 id="rfc.section.5.1.1"><a href="#rfc.section.5.1.1">5.1.1</a>&nbsp;<a id="header.max-forwards" href="#header.max-forwards">Max-Forwards</a></h3>
    1567       <p id="rfc.section.5.1.1.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;4.3.8</a>) and OPTIONS (<a href="#OPTIONS" id="rfc.xref.OPTIONS.2" title="OPTIONS">Section&nbsp;4.3.7</a>) methods to limit the number of times that the request is forwarded by proxies. This can be useful when the client is attempting
     1696      <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>
     1697      <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
    15681698         to trace a request which appears to be failing or looping mid-chain.
    15691699      </p>
    1570       <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>
    1571 </pre><p id="rfc.section.5.1.1.p.3">The Max-Forwards value is a decimal integer indicating the remaining number of times this request message can be forwarded.</p>
    1572       <p id="rfc.section.5.1.1.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).
    1573       </p>
    1574       <p id="rfc.section.5.1.1.p.5">The Max-Forwards header field <em class="bcp14">MAY</em> be ignored for all other request methods.
     1700      <div id="rfc.figure.u.21"></div><pre class="inline"><span id="rfc.iref.g.19"></span>  <a href="#header.max-forwards" class="smpl">Max-Forwards</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
     1701</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>
     1702      <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).
     1703      </p>
     1704      <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.
    15751705      </p>
    15761706      <div id="rfc.iref.e.1"></div>
    1577       <h3 id="rfc.section.5.1.2"><a href="#rfc.section.5.1.2">5.1.2</a>&nbsp;<a id="header.expect" href="#header.expect">Expect</a></h3>
    1578       <p id="rfc.section.5.1.2.p.1">The "Expect" header field is used to indicate that particular server behaviors are required by the client.</p>
    1579       <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>
     1707      <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>
     1708      <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>
     1709      <div id="rfc.figure.u.22"></div><pre class="inline"><span id="rfc.iref.g.20"></span><span id="rfc.iref.g.21"></span><span id="rfc.iref.g.22"></span><span id="rfc.iref.g.23"></span><span id="rfc.iref.g.24"></span>  <a href="#header.expect" class="smpl">Expect</a>       = 1#<a href="#header.expect" class="smpl">expectation</a>
    15801710 
    15811711  <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> ]
    … …  
    15851715  <a href="#header.expect" class="smpl">expect-name</a>  = <a href="#imported.abnf" class="smpl">token</a>
    15861716  <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>
    1587 </pre><p id="rfc.section.5.1.2.p.3">If all received Expect header field(s) are syntactically valid but contain an expectation that the recipient does not understand
     1717</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
    15881718         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.
    15891719      </p>
    1590       <p id="rfc.section.5.1.2.p.4">The only expectation defined by this specification is:</p>
    1591       <p id="rfc.section.5.1.2.p.5"><span id="rfc.iref.31"></span><span id="rfc.iref.e.2"></span> 100-continue
     1720      <p id="rfc.section.6.1.2.p.4">The only expectation defined by this specification is:</p>
     1721      <p id="rfc.section.6.1.2.p.5"><span id="rfc.iref.45"></span><span id="rfc.iref.e.2"></span> 100-continue
    15921722      </p>
    15931723      <ul class="empty">
    15941724         <li>The "100-continue" expectation is defined below. It does not support any expect-params.</li>
    15951725      </ul>
    1596       <p id="rfc.section.5.1.2.p.6">Comparison is case-insensitive for names (expect-name), and case-sensitive for values (expect-value).</p>
    1597       <p id="rfc.section.5.1.2.p.7">The Expect mechanism is hop-by-hop: the above requirements apply to any server, including proxies. However, the Expect header
     1726      <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>
     1727      <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
    15981728         field itself is end-to-end; it <em class="bcp14">MUST</em> be forwarded if the request is forwarded.
    15991729      </p>
    1600       <p id="rfc.section.5.1.2.p.8">Many older HTTP/1.0 and HTTP/1.1 applications do not understand the Expect header field.</p>
    1601       <h4 id="rfc.section.5.1.2.1"><a href="#rfc.section.5.1.2.1">5.1.2.1</a>&nbsp;<a id="use.of.the.100.status" href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></h4>
    1602       <p id="rfc.section.5.1.2.1.p.1">The purpose of the <a href="#status.100" class="smpl">100 (Continue)</a> status code (<a href="#status.100" id="rfc.xref.status.100.1" title="100 Continue">Section&nbsp;6.2.1</a>) is to allow a client that is sending a request message with a payload to determine if the origin server is willing to accept
     1730      <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>
     1731      <h4 id="rfc.section.6.1.2.1"><a href="#rfc.section.6.1.2.1">6.1.2.1</a>&nbsp;<a id="use.of.the.100.status" href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></h4>
     1732      <p id="rfc.section.6.1.2.1.p.1">The purpose of the <a href="#status.100" class="smpl">100 (Continue)</a> status code (<a href="#status.100" id="rfc.xref.status.100.1" title="100 Continue">Section&nbsp;7.2.1</a>) is to allow a client that is sending a request message with a payload to determine if the origin server is willing to accept
    16031733         the request (based on the request header fields) before the client sends the payload body. In some cases, it might either
    16041734         be inappropriate or highly inefficient for the client to send the payload body if the server will reject the message without
    16051735         looking at the body.
    16061736      </p>
    1607       <p id="rfc.section.5.1.2.1.p.2">Requirements for HTTP/1.1 clients: </p>
     1737      <p id="rfc.section.6.1.2.1.p.2">Requirements for HTTP/1.1 clients: </p>
    16081738      <ul>
    16091739         <li>If a client will wait for a <a href="#status.100" class="smpl">100 (Continue)</a> response before sending the payload body, it <em class="bcp14">MUST</em> send an <a href="#header.expect" class="smpl">Expect</a> header field with the "100-continue" expectation.
    … …  
    16121742         </li>
    16131743      </ul>
    1614       <p id="rfc.section.5.1.2.1.p.3">Because of the presence of older implementations, the protocol allows ambiguous situations in which a client might send "Expect:
     1744      <p id="rfc.section.6.1.2.1.p.3">Because of the presence of older implementations, the protocol allows ambiguous situations in which a client might send "Expect:
    16151745         100-continue" without receiving either a <a href="#status.417" class="smpl">417 (Expectation Failed)</a> or a <a href="#status.100" class="smpl">100 (Continue)</a> status code. Therefore, when a client sends this header field to an origin server (possibly via a proxy) from which it has
    16161746         never seen a <a href="#status.100" class="smpl">100 (Continue)</a> status code, the client <em class="bcp14">SHOULD NOT</em> wait for an indefinite period before sending the payload body.
    16171747      </p>
    1618       <p id="rfc.section.5.1.2.1.p.4">Requirements for HTTP/1.1 origin servers: </p>
     1748      <p id="rfc.section.6.1.2.1.p.4">Requirements for HTTP/1.1 origin servers: </p>
    16191749      <ul>
    16201750         <li>Upon receiving a request which includes an <a href="#header.expect" class="smpl">Expect</a> header field with the "100-continue" expectation, an origin server <em class="bcp14">MUST</em> either respond with <a href="#status.100" class="smpl">100 (Continue)</a> status code and continue to read from the input stream, or respond with a final status code. The origin server <em class="bcp14">MUST NOT</em> wait for the payload body before sending the <a href="#status.100" class="smpl">100 (Continue)</a> response. If it responds with a final status code, it <em class="bcp14">MAY</em> close the transport connection or it <em class="bcp14">MAY</em> continue to read and discard the rest of the request. It <em class="bcp14">MUST NOT</em> perform the request method if it returns a final status code.
    … …  
    16361766         </li>
    16371767      </ul>
    1638       <p id="rfc.section.5.1.2.1.p.5">Requirements for HTTP/1.1 proxies: </p>
     1768      <p id="rfc.section.6.1.2.1.p.5">Requirements for HTTP/1.1 proxies: </p>
    16391769      <ul>
    16401770         <li>If a proxy receives a request that includes an <a href="#header.expect" class="smpl">Expect</a> header field with the "100-continue" expectation, and the proxy either knows that the next-hop server complies with HTTP/1.1
    … …  
    16451775         <li>Proxies <em class="bcp14">SHOULD</em> maintain a record of the HTTP version numbers received from recently-referenced next-hop servers.
    16461776         </li>
    1647          <li>A proxy <em class="bcp14">MUST NOT</em> forward a <a href="#status.100" class="smpl">100 (Continue)</a> response if the request message was received from an HTTP/1.0 (or earlier) client and did not include an <a href="#header.expect" class="smpl">Expect</a> header field with the "100-continue" expectation. This requirement overrides the general rule for forwarding of <a href="#status.1xx" class="smpl">1xx</a> responses (see <a href="#status.100" id="rfc.xref.status.100.2" title="100 Continue">Section&nbsp;6.2.1</a>).
    1648          </li>
    1649       </ul>
    1650       <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</a>&nbsp;<a id="request.conditionals" href="#request.conditionals">Conditionals</a></h2>
    1651       <p id="rfc.section.5.2.p.1">Conditionals are request header fields that indicate a precondition to be tested before applying the method semantics to the
     1777         <li>A proxy <em class="bcp14">MUST NOT</em> forward a <a href="#status.100" class="smpl">100 (Continue)</a> response if the request message was received from an HTTP/1.0 (or earlier) client and did not include an <a href="#header.expect" class="smpl">Expect</a> header field with the "100-continue" expectation. This requirement overrides the general rule for forwarding of <a href="#status.1xx" class="smpl">1xx</a> responses (see <a href="#status.100" id="rfc.xref.status.100.2" title="100 Continue">Section&nbsp;7.2.1</a>).
     1778         </li>
     1779      </ul>
     1780      <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>
     1781      <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
    16521782         target resource. Each precondition is based on metadata that is expected to change if the selected representation of the target
    16531783         resource is changed. The HTTP/1.1 conditional request mechanisms are defined in <a href="#Part4" id="rfc.xref.Part4.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a>.
    … …  
    16851815         </table>
    16861816      </div>
    1687       <h2 id="rfc.section.5.3"><a href="#rfc.section.5.3">5.3</a>&nbsp;<a id="request.conneg" href="#request.conneg">Content Negotiation</a></h2>
     1817      <h2 id="rfc.section.6.3"><a href="#rfc.section.6.3">6.3</a>&nbsp;<a id="request.conneg" href="#request.conneg">Content Negotiation</a></h2>
    16881818      <div id="rfc.table.u.5">
    16891819         <table class="tt full left" cellpadding="3" cellspacing="0">
    … …  
    16971827               <tr>
    16981828                  <td class="left">Accept</td>
    1699                   <td class="left"><a href="#header.accept" id="rfc.xref.header.accept.2" title="Accept">Section&nbsp;5.3.2</a></td>
     1829                  <td class="left"><a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section&nbsp;6.3.2</a></td>
    17001830               </tr>
    17011831               <tr>
    17021832                  <td class="left">Accept-Charset</td>
    1703                   <td class="left"><a href="#header.accept-charset" id="rfc.xref.header.accept-charset.2" title="Accept-Charset">Section&nbsp;5.3.3</a></td>
     1833                  <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>
    17041834               </tr>
    17051835               <tr>
    17061836                  <td class="left">Accept-Encoding</td>
    1707                   <td class="left"><a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.2" title="Accept-Encoding">Section&nbsp;5.3.4</a></td>
     1837                  <td class="left"><a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.3" title="Accept-Encoding">Section&nbsp;6.3.4</a></td>
    17081838               </tr>
    17091839               <tr>
    17101840                  <td class="left">Accept-Language</td>
    1711                   <td class="left"><a href="#header.accept-language" id="rfc.xref.header.accept-language.2" title="Accept-Language">Section&nbsp;5.3.5</a></td>
     1841                  <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>
    17121842               </tr>
    17131843            </tbody>
    17141844         </table>
    17151845      </div>
    1716       <h3 id="rfc.section.5.3.1"><a href="#rfc.section.5.3.1">5.3.1</a>&nbsp;<a id="quality.values" href="#quality.values">Quality Values</a></h3>
    1717       <p id="rfc.section.5.3.1.p.1">Many of the request header fields for proactive content negotiation use a common parameter, named "q" (case-insensitive),
     1846      <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>
     1847      <p id="rfc.section.6.3.1.p.1">Many of the request header fields for proactive content negotiation use a common parameter, named "q" (case-insensitive),
    17181848         to assign a relative "weight" to the preference for that associated kind of content. This weight is referred to as a "quality
    17191849         value" (or "qvalue") because the same parameter name is often used within server configurations to assign a weight to the
    17201850         relative quality of the various representations that can be selected for a resource.
    17211851      </p>
    1722       <p id="rfc.section.5.3.1.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;
     1852      <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;
    17231853         a value of 0 means "not acceptable". If no "q" parameter is present, the default weight is 1.
    17241854      </p>
    1725       <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>
     1855      <div id="rfc.figure.u.23"></div><pre class="inline"><span id="rfc.iref.g.25"></span><span id="rfc.iref.g.26"></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>
    17261856  <a href="#quality.values" class="smpl">qvalue</a> = ( "0" [ "." 0*3<a href="#imported.abnf" class="smpl">DIGIT</a> ] )
    17271857         / ( "1" [ "." 0*3("0") ] )
    1728 </pre><p id="rfc.section.5.3.1.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
     1858</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
    17291859         fashion.
    17301860      </p>
    17311861      <div id="rfc.iref.a.1"></div>
    1732       <h3 id="rfc.section.5.3.2"><a href="#rfc.section.5.3.2">5.3.2</a>&nbsp;<a id="header.accept" href="#header.accept">Accept</a></h3>
    1733       <p id="rfc.section.5.3.2.p.1">The "Accept" header field can be used by user agents to specify response media types that are acceptable. Accept header fields
     1862      <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>
     1863      <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
    17341864         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
    17351865         for an in-line image.
    17361866      </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> ] )
     1867      <div id="rfc.figure.u.24"></div><pre class="inline"><span id="rfc.iref.g.27"></span><span id="rfc.iref.g.28"></span><span id="rfc.iref.g.29"></span><span id="rfc.iref.g.30"></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> ] )
    17381868 
    17391869  <a href="#header.accept" class="smpl">media-range</a>    = ( "*/*"
    … …  
    17431873  <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> )
    17441874  <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.5.3.2.p.3">The asterisk "*" character is used to group media types into ranges, with "*/*" indicating all media types and "type/*" indicating
     1875</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
    17461876         all subtypes of that type. The media-range <em class="bcp14">MAY</em> include media type parameters that are applicable to that range.
    17471877      </p>
    1748       <p id="rfc.section.5.3.2.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;5.3.1</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.5.3.2.p.5">
     1878      <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.
     1879      </p>
     1880      <div class="note" id="rfc.section.6.3.2.p.5">
    17511881         <p> <b>Note:</b> Use of the "q" parameter name to separate media type parameters from Accept extension parameters is due to historical practice.
    17521882            Although this prevents any media type parameter named "q" from being used with a media range, such an event is believed to
    … …  
    17551885         </p>
    17561886      </div>
    1757       <p id="rfc.section.5.3.2.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.5.3.2.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
     1887      <p id="rfc.section.6.3.2.p.6">The example</p>
     1888      <div id="rfc.figure.u.25"></div><pre class="text">  Accept: audio/*; q=0.2, audio/basic
     1889</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
    17601890         quality".
    17611891      </p>
    1762       <p id="rfc.section.5.3.2.p.9">A request without any Accept header field implies that the user agent will accept any media type in response. If an Accept
     1892      <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
    17631893         header field is present in a request and none of the available representations for the response have a media type that is
    17641894         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.
    17651895      </p>
    1766       <p id="rfc.section.5.3.2.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,
     1896      <p id="rfc.section.6.3.2.p.10">A more elaborate example is</p>
     1897      <div id="rfc.figure.u.26"></div><pre class="text">  Accept: text/plain; q=0.5, text/html,
    17681898          text/x-dvi; q=0.8, text/x-c
    1769 </pre><p id="rfc.section.5.3.2.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
     1899</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
    17701900         send the text/x-dvi representation, and if that does not exist, send the text/plain representation".
    17711901      </p>
    1772       <p id="rfc.section.5.3.2.p.13">Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies
     1902      <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
    17731903         to a given type, the most specific reference has precedence. For example,
    17741904      </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.5.3.2.p.15">have the following precedence: </p>
     1905      <div id="rfc.figure.u.27"></div><pre class="text">  Accept: text/*, text/plain, text/plain;format=flowed, */*
     1906</pre><p id="rfc.section.6.3.2.p.15">have the following precedence: </p>
    17771907      <ol>
    17781908         <li>text/plain;format=flowed</li>
    … …  
    17811911         <li>*/*</li>
    17821912      </ol>
    1783       <p id="rfc.section.5.3.2.p.16">The media type quality factor associated with a given type is determined by finding the media range with the highest precedence
     1913      <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
    17841914         which matches that type. For example,
    17851915      </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,
     1916      <div id="rfc.figure.u.28"></div><pre class="text">  Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1,
    17871917          text/html;level=2;q=0.4, */*;q=0.5
    1788 </pre><p id="rfc.section.5.3.2.p.18">would cause the following values to be associated:</p>
     1918</pre><p id="rfc.section.6.3.2.p.18">would cause the following values to be associated:</p>
    17891919      <div id="rfc.table.u.6">
    17901920         <table class="tt full left" cellpadding="3" cellspacing="0">
    … …  
    18231953         </table>
    18241954      </div>
    1825       <p id="rfc.section.5.3.2.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
     1955      <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
    18261956         is a closed system which cannot interact with other rendering agents, this default set ought to be configurable by the user.
    18271957      </p>
    18281958      <div id="rfc.iref.a.2"></div>
    1829       <h3 id="rfc.section.5.3.3"><a href="#rfc.section.5.3.3">5.3.3</a>&nbsp;<a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h3>
    1830       <p id="rfc.section.5.3.3.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response
     1959      <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>
     1960      <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
    18311961         payload. This field allows clients capable of understanding more comprehensive or special-purpose character encodings to signal
    18321962         that capability to a server which is capable of representing documents in those character encodings.
    18331963      </p>
    1834       <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> ] )
    1835 </pre><p id="rfc.section.5.3.3.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section&nbsp;8.3</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;5.3.1</a>. An example is
    1836       </p>
    1837       <div id="rfc.figure.u.22"></div><pre class="text">  Accept-Charset: iso-8859-5, unicode-1-1;q=0.8
    1838 </pre><p id="rfc.section.5.3.3.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere
     1964      <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.31"></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> ] )
     1965</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;3.1.1.2</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
     1966      </p>
     1967      <div id="rfc.figure.u.30"></div><pre class="text">  Accept-Charset: iso-8859-5, unicode-1-1;q=0.8
     1968</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
    18391969         in the Accept-Charset field. If no "*" is present in an Accept-Charset field, then any character encodings not explicitly
    18401970         mentioned in the field are considered "not acceptable" to the client.
    18411971      </p>
    1842       <p id="rfc.section.5.3.3.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response.</p>
    1843       <p id="rfc.section.5.3.3.p.7">If an Accept-Charset header field is present in a request and none of the available representations for the response have
     1972      <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>
     1973      <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
    18441974         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.
    18451975      </p>
    18461976      <div id="rfc.iref.a.3"></div>
    1847       <h3 id="rfc.section.5.3.4"><a href="#rfc.section.5.3.4">5.3.4</a>&nbsp;<a id="header.accept-encoding" href="#header.accept-encoding">Accept-Encoding</a></h3>
    1848       <p id="rfc.section.5.3.4.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;8.4</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when
     1977      <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>
     1978      <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;3.1.2.1</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when
    18491979         no encoding is preferred.
    18501980      </p>
    1851       <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> ] )
     1981      <div id="rfc.figure.u.31"></div><pre class="inline"><span id="rfc.iref.g.32"></span><span id="rfc.iref.g.33"></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> ] )
    18521982  <a href="#header.accept-encoding" class="smpl">codings</a>          = <a href="#content.codings" class="smpl">content-coding</a> / "identity" / "*"
    1853 </pre><p id="rfc.section.5.3.4.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;5.3.1</a>.
    1854       </p>
    1855       <p id="rfc.section.5.3.4.p.4">For example,</p>
    1856       <div id="rfc.figure.u.24"></div><pre class="text">  Accept-Encoding: compress, gzip
     1983</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>.
     1984      </p>
     1985      <p id="rfc.section.6.3.4.p.4">For example,</p>
     1986      <div id="rfc.figure.u.32"></div><pre class="text">  Accept-Encoding: compress, gzip
    18571987  Accept-Encoding:
    18581988  Accept-Encoding: *
    18591989  Accept-Encoding: compress;q=0.5, gzip;q=1.0
    18601990  Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0
    1861 </pre><p id="rfc.section.5.3.4.p.6">A server tests whether a content-coding for a given representation is acceptable, according to an Accept-Encoding field, using
     1991</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
    18621992         these rules:
    18631993      </p>
    … …  
    18702000         </li>
    18712001         <li>If the representation's content-coding is one of the content-codings listed in the Accept-Encoding field, then it is acceptable
    1872             unless it is accompanied by a qvalue of 0. (As defined in <a href="#quality.values" title="Quality Values">Section&nbsp;5.3.1</a>, a qvalue of 0 means "not acceptable".)
     2002            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".)
    18732003         </li>
    18742004         <li>If multiple content-codings are acceptable, then the acceptable content-coding with the highest non-zero qvalue is preferred.</li>
    18752005      </ol>
    1876       <p id="rfc.section.5.3.4.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
     2006      <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
    18772007         in response. If an Accept-Encoding header field is present in a request and none of the available representations for the
    18782008         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.
    18792009      </p>
    1880       <p id="rfc.section.5.3.4.p.8">A request without an Accept-Encoding header field implies that the user agent will accept any content-coding in response.</p>
    1881       <div class="note" id="rfc.section.5.3.4.p.9">
     2010      <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>
     2011      <div class="note" id="rfc.section.6.3.4.p.9">
    18822012         <p> <b>Note:</b> Most HTTP/1.0 applications do not recognize or obey qvalues associated with content-codings. This means that qvalues will
    18832013            not work and are not permitted with x-gzip or x-compress.
    … …  
    18852015      </div>
    18862016      <div id="rfc.iref.a.4"></div>
    1887       <h3 id="rfc.section.5.3.5"><a href="#rfc.section.5.3.5">5.3.5</a>&nbsp;<a id="header.accept-language" href="#header.accept-language">Accept-Language</a></h3>
    1888       <p id="rfc.section.5.3.5.p.1">The "Accept-Language" header field can be used by user agents to indicate the set of natural languages that are preferred
    1889          in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;8.6</a>.
    1890       </p>
    1891       <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> ] )
     2017      <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>
     2018      <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
     2019         in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;3.1.3.1</a>.
     2020      </p>
     2021      <div id="rfc.figure.u.33"></div><pre class="inline"><span id="rfc.iref.g.34"></span><span id="rfc.iref.g.35"></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> ] )
    18922022  <a href="#header.accept-language" class="smpl">language-range</a>  =
    18932023            &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;
    1894 </pre><p id="rfc.section.5.3.5.p.3">Each language-range can be given an associated quality value which represents an estimate of the user's preference for the
    1895          languages specified by that range, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;5.3.1</a>. For example,
    1896       </p>
    1897       <div id="rfc.figure.u.26"></div><pre class="text">  Accept-Language: da, en-gb;q=0.8, en;q=0.7
    1898 </pre><p id="rfc.section.5.3.5.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>)
    1899       </p>
    1900       <p id="rfc.section.5.3.5.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.
    1901       </p>
    1902       <div class="note" id="rfc.section.5.3.5.p.7">
     2024</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
     2025         languages specified by that range, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>. For example,
     2026      </p>
     2027      <div id="rfc.figure.u.34"></div><pre class="text">  Accept-Language: da, en-gb;q=0.8, en;q=0.7
     2028</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>)
     2029      </p>
     2030      <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.
     2031      </p>
     2032      <div class="note" id="rfc.section.6.3.5.p.7">
    19032033         <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>.
    19042034         </p>
    19052035      </div>
    1906       <p id="rfc.section.5.3.5.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic
     2036      <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
    19072037         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;10.5</a>.
    19082038      </p>
    1909       <p id="rfc.section.5.3.5.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice
     2039      <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
    19102040         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.
    19112041      </p>
    1912       <div class="note" id="rfc.section.5.3.5.p.10">
     2042      <div class="note" id="rfc.section.6.3.5.p.10">
    19132043         <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
    19142044            familiar with the details of language matching as described above, and ought to be provided appropriate guidance. As an example,
    … …  
    19172047         </p>
    19182048      </div>
    1919       <h2 id="rfc.section.5.4"><a href="#rfc.section.5.4">5.4</a>&nbsp;<a id="request.auth" href="#request.auth">Authentication</a></h2>
     2049      <h2 id="rfc.section.6.4"><a href="#rfc.section.6.4">6.4</a>&nbsp;<a id="request.auth" href="#request.auth">Authentication Credentials</a></h2>
    19202050      <div id="rfc.table.u.7">
    19212051         <table class="tt full left" cellpadding="3" cellspacing="0">
    … …  
    19382068         </table>
    19392069      </div>
    1940       <h2 id="rfc.section.5.5"><a href="#rfc.section.5.5">5.5</a>&nbsp;<a id="request.context" href="#request.context">Context</a></h2>
     2070      <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>
    19412071      <div id="rfc.table.u.8">
    19422072         <table class="tt full left" cellpadding="3" cellspacing="0">
    … …  
    19502080               <tr>
    19512081                  <td class="left">From</td>
    1952                   <td class="left"><a href="#header.from" id="rfc.xref.header.from.1" title="From">Section&nbsp;5.5.1</a></td>
     2082                  <td class="left"><a href="#header.from" id="rfc.xref.header.from.1" title="From">Section&nbsp;6.5.1</a></td>
    19532083               </tr>
    19542084               <tr>
    19552085                  <td class="left">Referer</td>
    1956                   <td class="left"><a href="#header.referer" id="rfc.xref.header.referer.1" title="Referer">Section&nbsp;5.5.2</a></td>
     2086                  <td class="left"><a href="#header.referer" id="rfc.xref.header.referer.1" title="Referer">Section&nbsp;6.5.2</a></td>
    19572087               </tr>
    19582088               <tr>
    19592089                  <td class="left">TE</td>
    1960                   <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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a></td>
     2090                  <td class="left"><a href="p1-messaging.html#header.te" title="TE">Section 4.3</a> of <a href="#Part1" id="rfc.xref.Part1.19"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a></td>
    19612091               </tr>
    19622092               <tr>
    19632093                  <td class="left">User-Agent</td>
    1964                   <td class="left"><a href="#header.user-agent" id="rfc.xref.header.user-agent.2" title="User-Agent">Section&nbsp;5.5.3</a></td>
     2094                  <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>
    19652095               </tr>
    19662096            </tbody>
    … …  
    19682098      </div>
    19692099      <div id="rfc.iref.f.1"></div>
    1970       <h3 id="rfc.section.5.5.1"><a href="#rfc.section.5.5.1">5.5.1</a>&nbsp;<a id="header.from" href="#header.from">From</a></h3>
    1971       <p id="rfc.section.5.5.1.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>:
    1972       </p>
    1973       <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>
     2100      <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>
     2101      <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>:
     2102      </p>
     2103      <div id="rfc.figure.u.35"></div><pre class="inline"><span id="rfc.iref.g.36"></span>  <a href="#header.from" class="smpl">From</a>    = <a href="#header.from" class="smpl">mailbox</a>
    19742104 
    19752105  <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;
    1976 </pre><p id="rfc.section.5.5.1.p.3">An example is:</p>
    1977       <div id="rfc.figure.u.28"></div><pre class="text">  From: webmaster@example.org
    1978 </pre><p id="rfc.section.5.5.1.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
     2106</pre><p id="rfc.section.6.5.1.p.3">An example is:</p>
     2107      <div id="rfc.figure.u.36"></div><pre class="text">  From: webmaster@example.org
     2108</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
    19792109         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
    19802110         end.
    19812111      </p>
    1982       <p id="rfc.section.5.5.1.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
     2112      <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
    19832113         issuer's address <em class="bcp14">SHOULD</em> be used.
    19842114      </p>
    1985       <p id="rfc.section.5.5.1.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
     2115      <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
    19862116         security policy. It is strongly recommended that the user be able to disable, enable, and modify the value of this field at
    19872117         any time prior to a request.
    19882118      </p>
    19892119      <div id="rfc.iref.r.2"></div>
    1990       <h3 id="rfc.section.5.5.2"><a href="#rfc.section.5.5.2">5.5.2</a>&nbsp;<a id="header.referer" href="#header.referer">Referer</a></h3>
    1991       <p id="rfc.section.5.5.2.p.1">The "Referer" [sic] header field allows the client to specify the URI of the resource from which the target URI was obtained
     2120      <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>
     2121      <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
    19922122         (the "referrer", although the header field is misspelled.).
    19932123      </p>
    1994       <p id="rfc.section.5.5.2.p.2">The Referer header field allows servers to generate lists of back-links to resources for interest, logging, optimized caching,
     2124      <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,
    19952125         etc. It also allows obsolete or mistyped links to be traced for maintenance. Some servers use Referer as a means of controlling
    19962126         where they allow links from (so-called "deep linking"), but legitimate requests do not always contain a Referer header field.
    19972127      </p>
    1998       <p id="rfc.section.5.5.2.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
     2128      <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
    19992129         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
    20002130         non-HTTP URIs (e.g., FTP).
    20012131      </p>
    2002       <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>
    2003 </pre><p id="rfc.section.5.5.2.p.5">Example:</p>
    2004       <div id="rfc.figure.u.30"></div><pre class="text">  Referer: http://www.example.org/hypertext/Overview.html
    2005 </pre><p id="rfc.section.5.5.2.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;10.2</a> for security considerations.
     2132      <div id="rfc.figure.u.37"></div><pre class="inline"><span id="rfc.iref.g.37"></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>
     2133</pre><p id="rfc.section.6.5.2.p.5">Example:</p>
     2134      <div id="rfc.figure.u.38"></div><pre class="text">  Referer: http://www.example.org/hypertext/Overview.html
     2135</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;10.2</a> for security considerations.
    20062136      </p>
    20072137      <div id="rfc.iref.u.1"></div>
    2008       <h3 id="rfc.section.5.5.3"><a href="#rfc.section.5.5.3">5.5.3</a>&nbsp;<a id="header.user-agent" href="#header.user-agent">User-Agent</a></h3>
    2009       <p id="rfc.section.5.5.3.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.
    2010       </p>
    2011       <p id="rfc.section.5.5.3.p.2">Typically, it is used for statistical purposes, the tracing of protocol violations, and tailoring responses to avoid particular
     2138      <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>
     2139      <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.
     2140      </p>
     2141      <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
    20122142         user agent limitations.
    20132143      </p>
    2014       <p id="rfc.section.5.5.3.p.3">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section&nbsp;8.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.17"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) identifying the agent and its significant subproducts. By convention, the product tokens are listed in order of their significance
     2144      <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;4</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.20"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) identifying the agent and its significant subproducts. By convention, the product tokens are listed in order of their significance
    20152145         for identifying the application.
    20162146      </p>
    2017       <p id="rfc.section.5.5.3.p.4">Because this field is usually sent on every request a user agent makes, implementations are encouraged not to include needlessly
     2147      <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
    20182148         fine-grained detail, and to limit (or even prohibit) the addition of subproducts by third parties. Overly long and detailed
    20192149         User-Agent field values make requests larger and can also be used to identify ("fingerprint") the user against their wishes.
    20202150      </p>
    2021       <p id="rfc.section.5.5.3.p.5">Likewise, implementations are encouraged not to use the product tokens of other implementations in order to declare compatibility
     2151      <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
    20222152         with them, as this circumvents the purpose of the field. Finally, they are encouraged not to use comments to identify products;
    20232153         doing so makes the field value more difficult to parse.
    20242154      </p>
    2025       <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> ) )
    2026 </pre><p id="rfc.section.5.5.3.p.7">Example:</p>
    2027       <div id="rfc.figure.u.32"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
    2028 </pre><h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a id="status.codes" href="#status.codes">Response Status Codes</a></h1>
    2029       <p id="rfc.section.6.p.1">The status-code element is a 3-digit integer result code of the attempt to understand and satisfy the request.</p>
    2030       <p id="rfc.section.6.p.2">HTTP status codes are extensible. HTTP applications are not required to understand the meaning of all registered status codes,
     2155      <div id="rfc.figure.u.39"></div><pre class="inline"><span id="rfc.iref.g.38"></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> ) )
     2156</pre><p id="rfc.section.6.5.3.p.7">Example:</p>
     2157      <div id="rfc.figure.u.40"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
     2158</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>
     2159      <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>
     2160      <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,
    20312161         though such understanding is obviously desirable. However, applications <em class="bcp14">MUST</em> understand the class of any status code, as indicated by the first digit, and treat any unrecognized response as being equivalent
    20322162         to the x00 status code of that class, with the exception that an unrecognized response <em class="bcp14">MUST NOT</em> be cached. For example, if an unrecognized status code of 431 is received by the client, it can safely assume that there was
    … …  
    20342164         information which will explain the unusual status.
    20352165      </p>
    2036       <p id="rfc.section.6.p.3">The first digit of the status-code defines the class of response. The last two digits do not have any categorization role.
     2166      <p id="rfc.section.7.p.3">The first digit of the status-code defines the class of response. The last two digits do not have any categorization role.
    20372167         There are 5 values for the first digit:
    20382168      </p>
    … …  
    20492179         </li>
    20502180      </ul>
    2051       <p id="rfc.section.6.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;3.1.1</a>).
    2052       </p>
    2053       <h2 id="rfc.section.6.1"><a href="#rfc.section.6.1">6.1</a>&nbsp;<a id="overview.of.status.codes" href="#overview.of.status.codes">Overview of Status Codes</a></h2>
    2054       <p id="rfc.section.6.1.p.1">The status codes listed below are defined in this specification, <a href="p4-conditional.html#status.code.definitions" title="Status Code Definitions">Section 4</a> of <a href="#Part4" id="rfc.xref.Part4.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a>, <a href="p5-range.html#status.code.definitions" title="Status Code Definitions">Section 3</a> of <a href="#Part5" id="rfc.xref.Part5.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a>, and <a href="p7-auth.html#status.code.definitions" title="Status Code Definitions">Section 3</a> of <a href="#Part7" id="rfc.xref.Part7.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Authentication">[Part7]</cite></a>. The reason phrases listed here are only recommendations — they can be replaced by local equivalents without affecting the
     2181      <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.3" title="Content-Type">Section&nbsp;3.1.1.5</a>).
     2182      </p>
     2183      <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>
     2184      <p id="rfc.section.7.1.p.1">The status codes listed below are defined in this specification, <a href="p4-conditional.html#status.code.definitions" title="Status Code Definitions">Section 4</a> of <a href="#Part4" id="rfc.xref.Part4.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a>, <a href="p5-range.html#status.code.definitions" title="Status Code Definitions">Section 3</a> of <a href="#Part5" id="rfc.xref.Part5.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a>, and <a href="p7-auth.html#status.code.definitions" title="Status Code Definitions">Section 3</a> of <a href="#Part7" id="rfc.xref.Part7.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Authentication">[Part7]</cite></a>. The reason phrases listed here are only recommendations — they can be replaced by local equivalents without affecting the
    20552185         protocol.
    20562186      </p>
    … …  
    20682198                  <td class="left">100</td>
    20692199                  <td class="left">Continue</td>
    2070                   <td class="left"><a href="#status.100" id="rfc.xref.status.100.3" title="100 Continue">Section&nbsp;6.2.1</a></td>
     2200                  <td class="left"><a href="#status.100" id="rfc.xref.status.100.3" title="100 Continue">Section&nbsp;7.2.1</a></td>
    20712201               </tr>
    20722202               <tr>
    20732203                  <td class="left">101</td>
    20742204                  <td class="left">Switching Protocols</td>
    2075                   <td class="left"><a href="#status.101" id="rfc.xref.status.101.1" title="101 Switching Protocols">Section&nbsp;6.2.2</a></td>
     2205                  <td class="left"><a href="#status.101" id="rfc.xref.status.101.1" title="101 Switching Protocols">Section&nbsp;7.2.2</a></td>
    20762206               </tr>
    20772207               <tr>
    20782208                  <td class="left">200</td>
    20792209                  <td class="left">OK</td>
    2080                   <td class="left"><a href="#status.200" id="rfc.xref.status.200.1" title="200 OK">Section&nbsp;6.3.1</a></td>
     2210                  <td class="left"><a href="#status.200" id="rfc.xref.status.200.1" title="200 OK">Section&nbsp;7.3.1</a></td>
    20812211               </tr>
    20822212               <tr>
    20832213                  <td class="left">201</td>
    20842214                  <td class="left">Created</td>
    2085                   <td class="left"><a href="#status.201" id="rfc.xref.status.201.1" title="201 Created">Section&nbsp;6.3.2</a></td>
     2215                  <td class="left"><a href="#status.201" id="rfc.xref.status.201.1" title="201 Created">Section&nbsp;7.3.2</a></td>
    20862216               </tr>
    20872217               <tr>
    20882218                  <td class="left">202</td>
    20892219                  <td class="left">Accepted</td>
    2090                   <td class="left"><a href="#status.202" id="rfc.xref.status.202.1" title="202 Accepted">Section&nbsp;6.3.3</a></td>
     2220                  <td class="left"><a href="#status.202" id="rfc.xref.status.202.1" title="202 Accepted">Section&nbsp;7.3.3</a></td>
    20912221               </tr>
    20922222               <tr>
    20932223                  <td class="left">203</td>
    20942224                  <td class="left">Non-Authoritative Information</td>
    2095                   <td class="left"><a href="#status.203" id="rfc.xref.status.203.1" title="203 Non-Authoritative Information">Section&nbsp;6.3.4</a></td>
     2225                  <td class="left"><a href="#status.203" id="rfc.xref.status.203.1" title="203 Non-Authoritative Information">Section&nbsp;7.3.4</a></td>
    20962226               </tr>
    20972227               <tr>
    20982228                  <td class="left">204</td>
    20992229                  <td class="left">No Content</td>
    2100                   <td class="left"><a href="#status.204" id="rfc.xref.status.204.1" title="204 No Content">Section&nbsp;6.3.5</a></td>
     2230                  <td class="left"><a href="#status.204" id="rfc.xref.status.204.1" title="204 No Content">Section&nbsp;7.3.5</a></td>
    21012231               </tr>
    21022232               <tr>
    21032233                  <td class="left">205</td>
    21042234                  <td class="left">Reset Content</td>
    2105                   <td class="left"><a href="#status.205" id="rfc.xref.status.205.1" title="205 Reset Content">Section&nbsp;6.3.6</a></td>
     2235                  <td class="left"><a href="#status.205" id="rfc.xref.status.205.1" title="205 Reset Content">Section&nbsp;7.3.6</a></td>
    21062236               </tr>
    21072237               <tr>
    … …  
    21132243                  <td class="left">300</td>
    21142244                  <td class="left">Multiple Choices</td>
    2115                   <td class="left"><a href="#status.300" id="rfc.xref.status.300.1" title="300 Multiple Choices">Section&nbsp;6.4.1</a></td>
     2245                  <td class="left"><a href="#status.300" id="rfc.xref.status.300.1" title="300 Multiple Choices">Section&nbsp;7.4.1</a></td>
    21162246               </tr>
    21172247               <tr>
    21182248                  <td class="left">301</td>
    21192249                  <td class="left">Moved Permanently</td>
    2120                   <td class="left"><a href="#status.301" id="rfc.xref.status.301.1" title="301 Moved Permanently">Section&nbsp;6.4.2</a></td>
     2250                  <td class="left"><a href="#status.301" id="rfc.xref.status.301.1" title="301 Moved Permanently">Section&nbsp;7.4.2</a></td>
    21212251               </tr>
    21222252               <tr>
    21232253                  <td class="left">302</td>
    21242254                  <td class="left">Found</td>
    2125                   <td class="left"><a href="#status.302" id="rfc.xref.status.302.1" title="302 Found">Section&nbsp;6.4.3</a></td>
     2255                  <td class="left"><a href="#status.302" id="rfc.xref.status.302.1" title="302 Found">Section&nbsp;7.4.3</a></td>
    21262256               </tr>
    21272257               <tr>
    21282258                  <td class="left">303</td>
    21292259                  <td class="left">See Other</td>
    2130                   <td class="left"><a href="#status.303" id="rfc.xref.status.303.1" title="303 See Other">Section&nbsp;6.4.4</a></td>
     2260                  <td class="left"><a href="#status.303" id="rfc.xref.status.303.1" title="303 See Other">Section&nbsp;7.4.4</a></td>
    21312261               </tr>
    21322262               <tr>
    … …  
    21382268                  <td class="left">305</td>
    21392269                  <td class="left">Use Proxy</td>
    2140                   <td class="left"><a href="#status.305" id="rfc.xref.status.305.1" title="305 Use Proxy">Section&nbsp;6.4.5</a></td>
     2270                  <td class="left"><a href="#status.305" id="rfc.xref.status.305.1" title="305 Use Proxy">Section&nbsp;7.4.5</a></td>
    21412271               </tr>
    21422272               <tr>
    21432273                  <td class="left">307</td>
    21442274                  <td class="left">Temporary Redirect</td>
    2145                   <td class="left"><a href="#status.307" id="rfc.xref.status.307.1" title="307 Temporary Redirect">Section&nbsp;6.4.7</a></td>
     2275                  <td class="left"><a href="#status.307" id="rfc.xref.status.307.1" title="307 Temporary Redirect">Section&nbsp;7.4.7</a></td>
    21462276               </tr>
    21472277               <tr>
    21482278                  <td class="left">400</td>
    21492279                  <td class="left">Bad Request</td>
    2150                   <td class="left"><a href="#status.400" id="rfc.xref.status.400.1" title="400 Bad Request">Section&nbsp;6.5.1</a></td>
     2280                  <td class="left"><a href="#status.400" id="rfc.xref.status.400.1" title="400 Bad Request">Section&nbsp;7.5.1</a></td>
    21512281               </tr>
    21522282               <tr>
    … …  
    21582288                  <td class="left">402</td>
    21592289                  <td class="left">Payment Required</td>
    2160                   <td class="left"><a href="#status.402" id="rfc.xref.status.402.1" title="402 Payment Required">Section&nbsp;6.5.2</a></td>
     2290                  <td class="left"><a href="#status.402" id="rfc.xref.status.402.1" title="402 Payment Required">Section&nbsp;7.5.2</a></td>
    21612291               </tr>
    21622292               <tr>
    21632293                  <td class="left">403</td>
    21642294                  <td class="left">Forbidden</td>
    2165                   <td class="left"><a href="#status.403" id="rfc.xref.status.403.1" title="403 Forbidden">Section&nbsp;6.5.3</a></td>
     2295                  <td class="left"><a href="#status.403" id="rfc.xref.status.403.1" title="403 Forbidden">Section&nbsp;7.5.3</a></td>
    21662296               </tr>
    21672297               <tr>
    21682298                  <td class="left">404</td>
    21692299                  <td class="left">Not Found</td>
    2170                   <td class="left"><a href="#status.404" id="rfc.xref.status.404.1" title="404 Not Found">Section&nbsp;6.5.4</a></td>
     2300                  <td class="left"><a href="#status.404" id="rfc.xref.status.404.1" title="404 Not Found">Section&nbsp;7.5.4</a></td>
    21712301               </tr>
    21722302               <tr>
    21732303                  <td class="left">405</td>
    21742304                  <td class="left">Method Not Allowed</td>
    2175                   <td class="left"><a href="#status.405" id="rfc.xref.status.405.1" title="405 Method Not Allowed">Section&nbsp;6.5.5</a></td>
     2305                  <td class="left"><a href="#status.405" id="rfc.xref.status.405.1" title="405 Method Not Allowed">Section&nbsp;7.5.5</a></td>
    21762306               </tr>
    21772307               <tr>
    21782308                  <td class="left">406</td>
    21792309                  <td class="left">Not Acceptable</td>
    2180                   <td class="left"><a href="#status.406" id="rfc.xref.status.406.1" title="406 Not Acceptable">Section&nbsp;6.5.6</a></td>
     2310                  <td class="left"><a href="#status.406" id="rfc.xref.status.406.1" title="406 Not Acceptable">Section&nbsp;7.5.6</a></td>
    21812311               </tr>
    21822312               <tr>
    … …  
    21882318                  <td class="left">408</td>
    21892319                  <td class="left">Request Time-out</td>
    2190                   <td class="left"><a href="#status.408" id="rfc.xref.status.408.1" title="408 Request Timeout">Section&nbsp;6.5.7</a></td>
     2320                  <td class="left"><a href="#status.408" id="rfc.xref.status.408.1" title="408 Request Timeout">Section&nbsp;7.5.7</a></td>
    21912321               </tr>
    21922322               <tr>
    21932323                  <td class="left">409</td>
    21942324                  <td class="left">Conflict</td>
    2195                   <td class="left"><a href="#status.409" id="rfc.xref.status.409.1" title="409 Conflict">Section&nbsp;6.5.8</a></td>
     2325                  <td class="left"><a href="#status.409" id="rfc.xref.status.409.1" title="409 Conflict">Section&nbsp;7.5.8</a></td>
    21962326               </tr>
    21972327               <tr>
    21982328                  <td class="left">410</td>
    21992329                  <td class="left">Gone</td>
    2200                   <td class="left"><a href="#status.410" id="rfc.xref.status.410.1" title="410 Gone">Section&nbsp;6.5.9</a></td>
     2330                  <td class="left"><a href="#status.410" id="rfc.xref.status.410.1" title="410 Gone">Section&nbsp;7.5.9</a></td>
    22012331               </tr>
    22022332               <tr>
    22032333                  <td class="left">411</td>
    22042334                  <td class="left">Length Required</td>
    2205                   <td class="left"><a href="#status.411" id="rfc.xref.status.411.1" title="411 Length Required">Section&nbsp;6.5.10</a></td>
     2335                  <td class="left"><a href="#status.411" id="rfc.xref.status.411.1" title="411 Length Required">Section&nbsp;7.5.10</a></td>
    22062336               </tr>
    22072337               <tr>
    … …  
    22132343                  <td class="left">413</td>
    22142344                  <td class="left">Request Representation Too Large</td>
    2215                   <td class="left"><a href="#status.413" id="rfc.xref.status.413.1" title="413 Request Representation Too Large">Section&nbsp;6.5.11</a></td>
     2345                  <td class="left"><a href="#status.413" id="rfc.xref.status.413.1" title="413 Request Representation Too Large">Section&nbsp;7.5.11</a></td>
    22162346               </tr>
    22172347               <tr>
    22182348                  <td class="left">414</td>
    22192349                  <td class="left">URI Too Long</td>
    2220                   <td class="left"><a href="#status.414" id="rfc.xref.status.414.1" title="414 URI Too Long">Section&nbsp;6.5.12</a></td>
     2350                  <td class="left"><a href="#status.414" id="rfc.xref.status.414.1" title="414 URI Too Long">Section&nbsp;7.5.12</a></td>
    22212351               </tr>
    22222352               <tr>
    22232353                  <td class="left">415</td>
    22242354                  <td class="left">Unsupported Media Type</td>
    2225                   <td class="left"><a href="#status.415" id="rfc.xref.status.415.1" title="415 Unsupported Media Type">Section&nbsp;6.5.13</a></td>
     2355                  <td class="left"><a href="#status.415" id="rfc.xref.status.415.1" title="415 Unsupported Media Type">Section&nbsp;7.5.13</a></td>
    22262356               </tr>
    22272357               <tr>
    … …  
    22332363                  <td class="left">417</td>
    22342364                  <td class="left">Expectation Failed</td>
    2235                   <td class="left"><a href="#status.417" id="rfc.xref.status.417.1" title="417 Expectation Failed">Section&nbsp;6.5.14</a></td>
     2365                  <td class="left"><a href="#status.417" id="rfc.xref.status.417.1" title="417 Expectation Failed">Section&nbsp;7.5.14</a></td>
    22362366               </tr>
    22372367               <tr>
    22382368                  <td class="left">426</td>
    22392369                  <td class="left">Upgrade Required</td>
    2240                   <td class="left"><a href="#status.426" id="rfc.xref.status.426.1" title="426 Upgrade Required">Section&nbsp;6.5.15</a></td>
     2370                  <td class="left"><a href="#status.426" id="rfc.xref.status.426.1" title="426 Upgrade Required">Section&nbsp;7.5.15</a></td>
    22412371               </tr>
    22422372               <tr>
    22432373                  <td class="left">500</td>
    22442374                  <td class="left">Internal Server Error</td>
    2245                   <td class="left"><a href="#status.500" id="rfc.xref.status.500.1" title="500 Internal Server Error">Section&nbsp;6.6.1</a></td>
     2375                  <td class="left"><a href="#status.500" id="rfc.xref.status.500.1" title="500 Internal Server Error">Section&nbsp;7.6.1</a></td>
    22462376               </tr>
    22472377               <tr>
    22482378                  <td class="left">501</td>
    22492379                  <td class="left">Not Implemented</td>
    2250                   <td class="left"><a href="#status.501" id="rfc.xref.status.501.1" title="501 Not Implemented">Section&nbsp;6.6.2</a></td>
     2380                  <td class="left"><a href="#status.501" id="rfc.xref.status.501.1" title="501 Not Implemented">Section&nbsp;7.6.2</a></td>
    22512381               </tr>
    22522382               <tr>
    22532383                  <td class="left">502</td>
    22542384                  <td class="left">Bad Gateway</td>
    2255                   <td class="left"><a href="#status.502" id="rfc.xref.status.502.1" title="502 Bad Gateway">Section&nbsp;6.6.3</a></td>
     2385                  <td class="left"><a href="#status.502" id="rfc.xref.status.502.1" title="502 Bad Gateway">Section&nbsp;7.6.3</a></td>
    22562386               </tr>
    22572387               <tr>
    22582388                  <td class="left">503</td>
    22592389                  <td class="left">Service Unavailable</td>
    2260                   <td class="left"><a href="#status.503" id="rfc.xref.status.503.1" title="503 Service Unavailable">Section&nbsp;6.6.4</a></td>
     2390                  <td class="left"><a href="#status.503" id="rfc.xref.status.503.1" title="503 Service Unavailable">Section&nbsp;7.6.4</a></td>
    22612391               </tr>
    22622392               <tr>
    22632393                  <td class="left">504</td>
    22642394                  <td class="left">Gateway Time-out</td>
    2265                   <td class="left"><a href="#status.504" id="rfc.xref.status.504.1" title="504 Gateway Timeout">Section&nbsp;6.6.5</a></td>
     2395                  <td class="left"><a href="#status.504" id="rfc.xref.status.504.1" title="504 Gateway Timeout">Section&nbsp;7.6.5</a></td>
    22662396               </tr>
    22672397               <tr>
    22682398                  <td class="left">505</td>
    22692399                  <td class="left">HTTP Version not supported</td>
    2270                   <td class="left"><a href="#status.505" id="rfc.xref.status.505.1" title="505 HTTP Version Not Supported">Section&nbsp;6.6.6</a></td>
     2400                  <td class="left"><a href="#status.505" id="rfc.xref.status.505.1" title="505 HTTP Version Not Supported">Section&nbsp;7.6.6</a></td>
    22712401               </tr>
    22722402            </tbody>
    22732403         </table>
    22742404      </div>
    2275       <p id="rfc.section.6.1.p.2">Note that this list is not exhaustive — it does not include extension status codes defined in other specifications.</p>
    2276       <h2 id="rfc.section.6.2"><a href="#rfc.section.6.2">6.2</a>&nbsp;<a id="status.1xx" href="#status.1xx">Informational 1xx</a></h2>
    2277       <div id="rfc.iref.53"></div>
     2405      <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>
     2406      <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>
     2407      <div id="rfc.iref.67"></div>
    22782408      <div id="rfc.iref.s.2"></div>
    2279       <p id="rfc.section.6.2.p.1">This class of status code indicates a provisional response, consisting only of the status-line and optional header fields,
     2409      <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,
    22802410         and is terminated by an empty line. There are no required header fields for this class of status code. Since HTTP/1.0 did
    22812411         not define any 1xx status codes, servers <em class="bcp14">MUST NOT</em> send a 1xx response to an HTTP/1.0 client except under experimental conditions.
    22822412      </p>
    2283       <p id="rfc.section.6.2.p.2">A client <em class="bcp14">MUST</em> be prepared to accept one or more 1xx status responses prior to a regular response, even if the client does not expect a <a href="#status.100" class="smpl">100
     2413      <p id="rfc.section.7.2.p.2">A client <em class="bcp14">MUST</em> be prepared to accept one or more 1xx status responses prior to a regular response, even if the client does not expect a <a href="#status.100" class="smpl">100
    22842414            (Continue)</a> status message. Unexpected 1xx status responses <em class="bcp14">MAY</em> be ignored by a user agent.
    22852415      </p>
    2286       <p id="rfc.section.6.2.p.3">Proxies <em class="bcp14">MUST</em> forward 1xx responses, unless the connection between the proxy and its client has been closed, or unless the proxy itself
     2416      <p id="rfc.section.7.2.p.3">Proxies <em class="bcp14">MUST</em> forward 1xx responses, unless the connection between the proxy and its client has been closed, or unless the proxy itself
    22872417         requested the generation of the 1xx response. (For example, if a proxy adds an "Expect: 100-continue" field when it forwards
    22882418         a request, then it need not forward the corresponding <a href="#status.100" class="smpl">100 (Continue)</a> response(s).)
    22892419      </p>
    2290       <div id="rfc.iref.54"></div>
    2291       <h3 id="rfc.section.6.2.1"><a href="#rfc.section.6.2.1">6.2.1</a>&nbsp;<a id="status.100" href="#status.100">100 Continue</a></h3>
    2292       <p id="rfc.section.6.2.1.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
     2420      <div id="rfc.iref.68"></div>
     2421      <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>
     2422      <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
    22932423         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
    2294          server <em class="bcp14">MUST</em> send a final response after the request has been completed. See <a href="#use.of.the.100.status" title="Use of the 100 (Continue) Status">Section&nbsp;5.1.2.1</a> for detailed discussion of the use and handling of this status code.
    2295       </p>
    2296       <div id="rfc.iref.54"></div>
    2297       <h3 id="rfc.section.6.2.2"><a href="#rfc.section.6.2.2">6.2.2</a>&nbsp;<a id="status.101" href="#status.101">101 Switching Protocols</a></h3>
    2298       <p id="rfc.section.6.2.2.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 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.18"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>), for a change in the application protocol being used on this connection. The server will switch protocols to those defined
     2424         server <em class="bcp14">MUST</em> send a final response after the request has been completed. See <a href="#use.of.the.100.status" title="Use of the 100 (Continue) Status">Section&nbsp;6.1.2.1</a> for detailed discussion of the use and handling of this status code.
     2425      </p>
     2426      <div id="rfc.iref.68"></div>
     2427      <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>
     2428      <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 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.21"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>), for a change in the application protocol being used on this connection. The server will switch protocols to those defined
    22992429         by the response's Upgrade header field immediately after the empty line which terminates the 101 response.
    23002430      </p>
    2301       <p id="rfc.section.6.2.2.p.2">The protocol <em class="bcp14">SHOULD</em> be switched only when it is advantageous to do so. For example, switching to a newer version of HTTP is advantageous over
     2431      <p id="rfc.section.7.2.2.p.2">The protocol <em class="bcp14">SHOULD</em> be switched only when it is advantageous to do so. For example, switching to a newer version of HTTP is advantageous over
    23022432         older versions, and switching to a real-time, synchronous protocol might be advantageous when delivering resources that use
    23032433         such features.
    23042434      </p>
    2305       <h2 id="rfc.section.6.3"><a href="#rfc.section.6.3">6.3</a>&nbsp;<a id="status.2xx" href="#status.2xx">Successful 2xx</a></h2>
    2306       <div id="rfc.iref.54"></div>
     2435      <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>
     2436      <div id="rfc.iref.68"></div>
    23072437      <div id="rfc.iref.s.3"></div>
    2308       <p id="rfc.section.6.3.p.1">This class of status code indicates that the client's request was successfully received, understood, and accepted.</p>
    2309       <div id="rfc.iref.55"></div>
    2310       <h3 id="rfc.section.6.3.1"><a href="#rfc.section.6.3.1">6.3.1</a>&nbsp;<a id="status.200" href="#status.200">200 OK</a></h3>
    2311       <p id="rfc.section.6.3.1.p.1">The request has succeeded. The payload returned with the response is dependent on the method used in the request, for example: </p>
     2438      <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>
     2439      <div id="rfc.iref.69"></div>
     2440      <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>
     2441      <p id="rfc.section.7.3.1.p.1">The request has succeeded. The payload returned with the response is dependent on the method used in the request, for example: </p>
    23122442      <dl>
    23132443         <dt>GET</dt>
    … …  
    23202450         <dd>a representation containing the request message as received by the end server.</dd>
    23212451      </dl>
    2322       <p id="rfc.section.6.3.1.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.Part6.8"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 200 responses.
    2323       </p>
    2324       <div id="rfc.iref.55"></div>
    2325       <h3 id="rfc.section.6.3.2"><a href="#rfc.section.6.3.2">6.3.2</a>&nbsp;<a id="status.201" href="#status.201">201 Created</a></h3>
    2326       <p id="rfc.section.6.3.2.p.1">The request has been fulfilled and has resulted in one or more new resources being created.</p>
    2327       <p id="rfc.section.6.3.2.p.2">Newly created resources are typically linked to from the response payload, with the most relevant URI also being carried in
     2452      <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.Part6.8"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 200 responses.
     2453      </p>
     2454      <div id="rfc.iref.69"></div>
     2455      <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>
     2456      <p id="rfc.section.7.3.2.p.1">The request has been fulfilled and has resulted in one or more new resources being created.</p>
     2457      <p id="rfc.section.7.3.2.p.2">Newly created resources are typically linked to from the response payload, with the most relevant URI also being carried in
    23282458         the <a href="#header.location" class="smpl">Location</a> header field. If the newly created resource's URI is the same as the Effective Request URI, this information can be omitted
    23292459         (e.g., in the case of a response to a PUT request).
    23302460      </p>
    2331       <p id="rfc.section.6.3.2.p.3">The origin server <em class="bcp14">MUST</em> create the resource(s) before returning the 201 status code. If the action cannot be carried out immediately, the server <em class="bcp14">SHOULD</em> respond with <a href="#status.202" class="smpl">202 (Accepted)</a> response instead.
    2332       </p>
    2333       <p id="rfc.section.6.3.2.p.4">A 201 response <em class="bcp14">MAY</em> contain an <a href="p4-conditional.html#header.etag" class="smpl">ETag</a> response header field indicating the current value of the entity-tag for the representation of the resource identified by
     2461      <p id="rfc.section.7.3.2.p.3">The origin server <em class="bcp14">MUST</em> create the resource(s) before returning the 201 status code. If the action cannot be carried out immediately, the server <em class="bcp14">SHOULD</em> respond with <a href="#status.202" class="smpl">202 (Accepted)</a> response instead.
     2462      </p>
     2463      <p id="rfc.section.7.3.2.p.4">A 201 response <em class="bcp14">MAY</em> contain an <a href="p4-conditional.html#header.etag" class="smpl">ETag</a> response header field indicating the current value of the entity-tag for the representation of the resource identified by
    23342464         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.Part4.10"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a>).
    23352465      </p>
    2336       <div id="rfc.iref.55"></div>
    2337       <h3 id="rfc.section.6.3.3"><a href="#rfc.section.6.3.3">6.3.3</a>&nbsp;<a id="status.202" href="#status.202">202 Accepted</a></h3>
    2338       <p id="rfc.section.6.3.3.p.1">The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually
     2466      <div id="rfc.iref.69"></div>
     2467      <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>
     2468      <p id="rfc.section.7.3.3.p.1">The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually
    23392469         be acted upon, as it might be disallowed when processing actually takes place. There is no facility for re-sending a status
    23402470         code from an asynchronous operation such as this.
    23412471      </p>
    2342       <p id="rfc.section.6.3.3.p.2">The 202 response is intentionally non-committal. Its purpose is to allow a server to accept a request for some other process
     2472      <p id="rfc.section.7.3.3.p.2">The 202 response is intentionally non-committal. Its purpose is to allow a server to accept a request for some other process
    23432473         (perhaps a batch-oriented process that is only run once per day) without requiring that the user agent's connection to the
    23442474         server persist until the process is completed. The representation returned with this response <em class="bcp14">SHOULD</em> include an indication of the request's current status and either a pointer to a status monitor or some estimate of when the
    23452475         user can expect the request to be fulfilled.
    23462476      </p>
    2347       <div id="rfc.iref.55"></div>
    2348       <h3 id="rfc.section.6.3.4"><a href="#rfc.section.6.3.4">6.3.4</a>&nbsp;<a id="status.203" href="#status.203">203 Non-Authoritative Information</a></h3>
    2349       <p id="rfc.section.6.3.4.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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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.Part6.9"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>).
    2350       </p>
    2351       <p id="rfc.section.6.3.4.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
     2477      <div id="rfc.iref.69"></div>
     2478      <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>
     2479      <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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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.Part6.9"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>).
     2480      </p>
     2481      <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
    23522482         (<a href="p6-cache.html#header.warning" title="Warning">Section 7.5</a> of <a href="#Part6" id="rfc.xref.Part6.10"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) is appropriate.
    23532483      </p>
    2354       <p id="rfc.section.6.3.4.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.Part6.11"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 203 responses.
    2355       </p>
    2356       <div id="rfc.iref.55"></div>
    2357       <h3 id="rfc.section.6.3.5"><a href="#rfc.section.6.3.5">6.3.5</a>&nbsp;<a id="status.204" href="#status.204">204 No Content</a></h3>
    2358       <p id="rfc.section.6.3.5.p.1">The 204 (No Content) status code indicates that the server has successfully fulfilled the request and that there is no additional
     2484      <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.Part6.11"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 203 responses.
     2485      </p>
     2486      <div id="rfc.iref.69"></div>
     2487      <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>
     2488      <p id="rfc.section.7.3.5.p.1">The 204 (No Content) status code indicates that the server has successfully fulfilled the request and that there is no additional
    23592489         content to return in the response payload body. Metadata in the response header fields refer to the target resource and its
    23602490         current representation after the requested action.
    23612491      </p>
    2362       <p id="rfc.section.6.3.5.p.2">For example, if a 204 status code is received in response to a PUT request and the response contains an <a href="p4-conditional.html#header.etag" class="smpl">ETag</a> header field, then the PUT was successful and the ETag field-value contains the entity-tag for the new representation of that
     2492      <p id="rfc.section.7.3.5.p.2">For example, if a 204 status code is received in response to a PUT request and the response contains an <a href="p4-conditional.html#header.etag" class="smpl">ETag</a> header field, then the PUT was successful and the ETag field-value contains the entity-tag for the new representation of that
    23632493         target resource.
    23642494      </p>
    2365       <p id="rfc.section.6.3.5.p.3">The 204 response allows a server to indicate that the action has been successfully applied to the target resource while implying
     2495      <p id="rfc.section.7.3.5.p.3">The 204 response allows a server to indicate that the action has been successfully applied to the target resource while implying
    23662496         that the user agent <em class="bcp14">SHOULD NOT</em> traverse away from its current "document view" (if any). The server assumes that the user agent will provide some indication
    23672497         of the success to its user, in accord with its own interface, and apply any new or updated metadata in the response to the
    23682498         active representation.
    23692499      </p>
    2370       <p id="rfc.section.6.3.5.p.4">For example, a 204 status code is commonly used with document editing interfaces corresponding to a "save" action, such that
     2500      <p id="rfc.section.7.3.5.p.4">For example, a 204 status code is commonly used with document editing interfaces corresponding to a "save" action, such that
    23712501         the document being saved remains available to the user for editing. It is also frequently used with interfaces that expect
    23722502         automated data transfers to be prevalent, such as within distributed version control systems.
    23732503      </p>
    2374       <p id="rfc.section.6.3.5.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.
    2375       </p>
    2376       <div id="rfc.iref.55"></div>
    2377       <h3 id="rfc.section.6.3.6"><a href="#rfc.section.6.3.6">6.3.6</a>&nbsp;<a id="status.205" href="#status.205">205 Reset Content</a></h3>
    2378       <p id="rfc.section.6.3.6.p.1">The server has fulfilled the request and the user agent <em class="bcp14">SHOULD</em> reset the document view which caused the request to be sent. This response is primarily intended to allow input for actions
     2504      <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.
     2505      </p>
     2506      <div id="rfc.iref.69"></div>
     2507      <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>
     2508      <p id="rfc.section.7.3.6.p.1">The server has fulfilled the request and the user agent <em class="bcp14">SHOULD</em> reset the document view which caused the request to be sent. This response is primarily intended to allow input for actions
    23792509         to take place via user input, followed by a clearing of the form in which the input is given so that the user can easily initiate
    23802510         another input action.
    23812511      </p>
    2382       <p id="rfc.section.6.3.6.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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>.
    2383       </p>
    2384       <h2 id="rfc.section.6.4"><a href="#rfc.section.6.4">6.4</a>&nbsp;<a id="status.3xx" href="#status.3xx">Redirection 3xx</a></h2>
    2385       <div id="rfc.iref.55"></div>
     2512      <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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>.
     2513      </p>
     2514      <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>
     2515      <div id="rfc.iref.69"></div>
    23862516      <div id="rfc.iref.s.4"></div>
    2387       <p id="rfc.section.6.4.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.
     2517      <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.
    23882518         If the required action involves a subsequent HTTP request, it <em class="bcp14">MAY</em> be carried out by the user agent without interaction with the user if and only if the method used in the second request is
    2389          known to be "safe", as defined in <a href="#safe.methods" title="Safe Methods">Section&nbsp;4.2.1</a>.
    2390       </p>
    2391       <p id="rfc.section.6.4.p.2">There are several types of redirects: </p>
     2519         known to be "safe", as defined in <a href="#safe.methods" title="Safe Methods">Section&nbsp;5.2.1</a>.
     2520      </p>
     2521      <p id="rfc.section.7.4.p.2">There are several types of redirects: </p>
    23922522      <ol>
    23932523         <li>
    … …  
    24122542         </li>
    24132543      </ol>
    2414       <div class="note" id="rfc.section.6.4.p.3">
     2544      <div class="note" id="rfc.section.7.4.p.3">
    24152545         <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
    24162546            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.RFC2068.2"><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
    … …  
    24182548         </p>
    24192549      </div>
    2420       <p id="rfc.section.6.4.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;7.1.2</a>.
    2421       </p>
    2422       <p id="rfc.section.6.4.p.5">Note that for methods not known to be "safe", as defined in <a href="#safe.methods" title="Safe Methods">Section&nbsp;4.2.1</a>, automatic redirection needs to done with care, since the redirect might change the conditions under which the request was
     2550      <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;8.1.2</a>.
     2551      </p>
     2552      <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
    24232553         issued.
    24242554      </p>
    2425       <p id="rfc.section.6.4.p.6">Clients <em class="bcp14">SHOULD</em> detect and intervene in cyclical redirections (i.e., "infinite" redirection loops).
    2426       </p>
    2427       <div class="note" id="rfc.section.6.4.p.7">
     2555      <p id="rfc.section.7.4.p.6">Clients <em class="bcp14">SHOULD</em> detect and intervene in cyclical redirections (i.e., "infinite" redirection loops).
     2556      </p>
     2557      <div class="note" id="rfc.section.7.4.p.7">
    24282558         <p> <b>Note:</b> An earlier version of this specification recommended a maximum of five redirections (<a href="#RFC2068" id="rfc.xref.RFC2068.3"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a>, <a href="http://tools.ietf.org/html/rfc2068#section-10.3">Section 10.3</a>). Content developers need to be aware that some clients might implement such a fixed limitation.
    24292559         </p>
    24302560      </div>
    2431       <div id="rfc.iref.56"></div>
    2432       <h3 id="rfc.section.6.4.1"><a href="#rfc.section.6.4.1">6.4.1</a>&nbsp;<a id="status.300" href="#status.300">300 Multiple Choices</a></h3>
    2433       <p id="rfc.section.6.4.1.p.1">The target resource has more than one representation, each with its own specific location, and reactive negotiation information
     2561      <div id="rfc.iref.70"></div>
     2562      <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>
     2563      <p id="rfc.section.7.4.1.p.1">The target resource has more than one representation, each with its own specific location, and reactive negotiation information
    24342564         (<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
    24352565         location.
    24362566      </p>
    2437       <p id="rfc.section.6.4.1.p.2">Unless it was a HEAD request, the response <em class="bcp14">SHOULD</em> include a representation containing a list of representation metadata and location(s) from which the user or user agent can
     2567      <p id="rfc.section.7.4.1.p.2">Unless it was a HEAD request, the response <em class="bcp14">SHOULD</em> include a representation containing a list of representation metadata and location(s) from which the user or user agent can
    24382568         choose the one most appropriate. Depending upon the format and the capabilities of the user agent, selection of the most appropriate
    24392569         choice <em class="bcp14">MAY</em> be performed automatically. However, this specification does not define any standard for such automatic selection.
    24402570      </p>
    2441       <p id="rfc.section.6.4.1.p.3">If the server has a preferred choice of representation, it <em class="bcp14">SHOULD</em> include the specific URI for that representation in the <a href="#header.location" class="smpl">Location</a> field; user agents <em class="bcp14">MAY</em> use the Location field value for automatic redirection.
    2442       </p>
    2443       <p id="rfc.section.6.4.1.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.Part6.12"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 300 responses.
    2444       </p>
    2445       <div id="rfc.iref.56"></div>
    2446       <h3 id="rfc.section.6.4.2"><a href="#rfc.section.6.4.2">6.4.2</a>&nbsp;<a id="status.301" href="#status.301">301 Moved Permanently</a></h3>
    2447       <p id="rfc.section.6.4.2.p.1">The target resource has been assigned a new permanent URI and any future references to this resource <em class="bcp14">SHOULD</em> use one of the returned URIs. Clients with link editing capabilities ought to automatically re-link references to the effective
     2571      <p id="rfc.section.7.4.1.p.3">If the server has a preferred choice of representation, it <em class="bcp14">SHOULD</em> include the specific URI for that representation in the <a href="#header.location" class="smpl">Location</a> field; user agents <em class="bcp14">MAY</em> use the Location field value for automatic redirection.
     2572      </p>
     2573      <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.Part6.12"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 300 responses.
     2574      </p>
     2575      <div id="rfc.iref.70"></div>
     2576      <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>
     2577      <p id="rfc.section.7.4.2.p.1">The target resource has been assigned a new permanent URI and any future references to this resource <em class="bcp14">SHOULD</em> use one of the returned URIs. Clients with link editing capabilities ought to automatically re-link references to the effective
    24482578         request URI to one or more of the new references returned by the server, where possible.
    24492579      </p>
    2450       <p id="rfc.section.6.4.2.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.Part6.13"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 301 responses.
    2451       </p>
    2452       <p id="rfc.section.6.4.2.p.3">The new permanent URI <em class="bcp14">SHOULD</em> be given by the <a href="#header.location" class="smpl">Location</a> field in the response. A response payload can contain a short hypertext note with a hyperlink to the new URI(s).
    2453       </p>
    2454       <div class="note" id="rfc.section.6.4.2.p.4">
     2580      <p id="rfc.section.7.4.2.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.Part6.13"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 301 responses.
     2581      </p>
     2582      <p id="rfc.section.7.4.2.p.3">The new permanent URI <em class="bcp14">SHOULD</em> be given by the <a href="#header.location" class="smpl">Location</a> field in the response. A response payload can contain a short hypertext note with a hyperlink to the new URI(s).
     2583      </p>
     2584      <div class="note" id="rfc.section.7.4.2.p.4">
    24552585         <p> <b>Note:</b> For historic reasons, user agents <em class="bcp14">MAY</em> change the request method from POST to GET for the subsequent request. If this behavior is undesired, status code <a href="#status.307" class="smpl">307 (Temporary Redirect)</a> can be used instead.
    24562586         </p>
    24572587      </div>
    2458       <div id="rfc.iref.56"></div>
    2459       <h3 id="rfc.section.6.4.3"><a href="#rfc.section.6.4.3">6.4.3</a>&nbsp;<a id="status.302" href="#status.302">302 Found</a></h3>
    2460       <p id="rfc.section.6.4.3.p.1">The target resource resides temporarily under a different URI. Since the redirection might be altered on occasion, the client <em class="bcp14">SHOULD</em> continue to use the effective request URI for future requests.
    2461       </p>
    2462       <p id="rfc.section.6.4.3.p.2">The temporary URI <em class="bcp14">SHOULD</em> be given by the <a href="#header.location" class="smpl">Location</a> field in the response. A response payload can contain a short hypertext note with a hyperlink to the new URI(s).
    2463       </p>
    2464       <div class="note" id="rfc.section.6.4.3.p.3">
     2588      <div id="rfc.iref.70"></div>
     2589      <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>
     2590      <p id="rfc.section.7.4.3.p.1">The target resource resides temporarily under a different URI. Since the redirection might be altered on occasion, the client <em class="bcp14">SHOULD</em> continue to use the effective request URI for future requests.
     2591      </p>
     2592      <p id="rfc.section.7.4.3.p.2">The temporary URI <em class="bcp14">SHOULD</em> be given by the <a href="#header.location" class="smpl">Location</a> field in the response. A response payload can contain a short hypertext note with a hyperlink to the new URI(s).
     2593      </p>
     2594      <div class="note" id="rfc.section.7.4.3.p.3">
    24652595         <p> <b>Note:</b> For historic reasons, user agents <em class="bcp14">MAY</em> change the request method from POST to GET for the subsequent request. If this behavior is undesired, status code <a href="#status.307" class="smpl">307 (Temporary Redirect)</a> can be used instead.
    24662596         </p>
    24672597      </div>
    2468       <div id="rfc.iref.56"></div>
    2469       <h3 id="rfc.section.6.4.4"><a href="#rfc.section.6.4.4">6.4.4</a>&nbsp;<a id="status.303" href="#status.303">303 See Other</a></h3>
    2470       <p id="rfc.section.6.4.4.p.1">The 303 status code indicates that the server is redirecting the user agent to a different resource, as indicated by a URI
     2598      <div id="rfc.iref.70"></div>
     2599      <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>
     2600      <p id="rfc.section.7.4.4.p.1">The 303 status code indicates that the server is redirecting the user agent to a different resource, as indicated by a URI
    24712601         in the <a href="#header.location" class="smpl">Location</a> header field, that is intended to provide an indirect response to the original request. In order to satisfy the original request,
    24722602         a user agent <em class="bcp14">SHOULD</em> perform a retrieval request using the Location URI (a GET or HEAD request if using HTTP), which can itself be redirected further,
    … …  
    24742604         not considered equivalent to the effective request URI.
    24752605      </p>
    2476       <p id="rfc.section.6.4.4.p.2">This status code is generally applicable to any HTTP method. It is primarily used to allow the output of a POST action to
     2606      <p id="rfc.section.7.4.4.p.2">This status code is generally applicable to any HTTP method. It is primarily used to allow the output of a POST action to
    24772607         redirect the user agent to a selected resource, since doing so provides the information corresponding to the POST response
    24782608         in a form that can be separately identified, bookmarked, and cached independent of the original request.
    24792609      </p>
    2480       <p id="rfc.section.6.4.4.p.3">A 303 response to a GET request indicates that the requested resource does not have a representation of its own that can be
     2610      <p id="rfc.section.7.4.4.p.3">A 303 response to a GET request indicates that the requested resource does not have a representation of its own that can be
    24812611         transferred by the server over HTTP. The <a href="#header.location" class="smpl">Location</a> URI indicates a resource that is descriptive of the target resource, such that the follow-on representation might be useful
    24822612         to recipients without implying that it adequately represents the target resource. Note that answers to the questions of what
    … …  
    24842614         and thus entirely determined by the URI owner(s).
    24852615      </p>
    2486       <p id="rfc.section.6.4.4.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.
    2487       </p>
    2488       <div id="rfc.iref.56"></div>
    2489       <h3 id="rfc.section.6.4.5"><a href="#rfc.section.6.4.5">6.4.5</a>&nbsp;<a id="status.305" href="#status.305">305 Use Proxy</a></h3>
    2490       <p id="rfc.section.6.4.5.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.
    2491       </p>
    2492       <div id="rfc.iref.56"></div>
    2493       <h3 id="rfc.section.6.4.6"><a href="#rfc.section.6.4.6">6.4.6</a>&nbsp;<a id="status.306" href="#status.306">306 (Unused)</a></h3>
    2494       <p id="rfc.section.6.4.6.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>
    2495       <div id="rfc.iref.56"></div>
    2496       <h3 id="rfc.section.6.4.7"><a href="#rfc.section.6.4.7">6.4.7</a>&nbsp;<a id="status.307" href="#status.307">307 Temporary Redirect</a></h3>
    2497       <p id="rfc.section.6.4.7.p.1">The target resource resides temporarily under a different URI. Since the redirection can change over time, the client <em class="bcp14">SHOULD</em> continue to use the effective request URI for future requests.
    2498       </p>
    2499       <p id="rfc.section.6.4.7.p.2">The temporary URI <em class="bcp14">SHOULD</em> be given by the <a href="#header.location" class="smpl">Location</a> field in the response. A response payload can contain a short hypertext note with a hyperlink to the new URI(s).
    2500       </p>
    2501       <div class="note" id="rfc.section.6.4.7.p.3">
     2616      <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.
     2617      </p>
     2618      <div id="rfc.iref.70"></div>
     2619      <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>
     2620      <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.
     2621      </p>
     2622      <div id="rfc.iref.70"></div>
     2623      <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>
     2624      <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>
     2625      <div id="rfc.iref.70"></div>
     2626      <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>
     2627      <p id="rfc.section.7.4.7.p.1">The target resource resides temporarily under a different URI. Since the redirection can change over time, the client <em class="bcp14">SHOULD</em> continue to use the effective request URI for future requests.
     2628      </p>
     2629      <p id="rfc.section.7.4.7.p.2">The temporary URI <em class="bcp14">SHOULD</em> be given by the <a href="#header.location" class="smpl">Location</a> field in the response. A response payload can contain a short hypertext note with a hyperlink to the new URI(s).
     2630      </p>
     2631      <div class="note" id="rfc.section.7.4.7.p.3">
    25022632         <p> <b>Note:</b> This status code is similar to <a href="#status.302" class="smpl">302 (Found)</a>, except that it does not allow rewriting the request method from POST to GET. This specification defines no equivalent counterpart
    25032633            for <a href="#status.301" class="smpl">301 (Moved
    … …  
    25052635         </p>
    25062636      </div>
    2507       <h2 id="rfc.section.6.5"><a href="#rfc.section.6.5">6.5</a>&nbsp;<a id="status.4xx" href="#status.4xx">Client Error 4xx</a></h2>
    2508       <div id="rfc.iref.56"></div>
     2637      <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>
     2638      <div id="rfc.iref.70"></div>
    25092639      <div id="rfc.iref.s.5"></div>
    2510       <p id="rfc.section.6.5.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
     2640      <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
    25112641         request, the server <em class="bcp14">SHOULD</em> include a representation containing an explanation of the error situation, and whether it is a temporary or permanent condition.
    25122642         These status codes are applicable to any request method. User agents <em class="bcp14">SHOULD</em> display any included representation to the user.
    25132643      </p>
    2514       <div id="rfc.iref.57"></div>
    2515       <h3 id="rfc.section.6.5.1"><a href="#rfc.section.6.5.1">6.5.1</a>&nbsp;<a id="status.400" href="#status.400">400 Bad Request</a></h3>
    2516       <p id="rfc.section.6.5.1.p.1">The server cannot or will not process the request, due to a client error (e.g., malformed syntax).</p>
    2517       <div id="rfc.iref.57"></div>
    2518       <h3 id="rfc.section.6.5.2"><a href="#rfc.section.6.5.2">6.5.2</a>&nbsp;<a id="status.402" href="#status.402">402 Payment Required</a></h3>
    2519       <p id="rfc.section.6.5.2.p.1">This code is reserved for future use.</p>
    2520       <div id="rfc.iref.57"></div>
    2521       <h3 id="rfc.section.6.5.3"><a href="#rfc.section.6.5.3">6.5.3</a>&nbsp;<a id="status.403" href="#status.403">403 Forbidden</a></h3>
    2522       <p id="rfc.section.6.5.3.p.1">The server understood the request, but refuses to authorize it. Providing different user authentication credentials might
     2644      <div id="rfc.iref.71"></div>
     2645      <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>
     2646      <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>
     2647      <div id="rfc.iref.71"></div>
     2648      <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>
     2649      <p id="rfc.section.7.5.2.p.1">This code is reserved for future use.</p>
     2650      <div id="rfc.iref.71"></div>
     2651      <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>
     2652      <p id="rfc.section.7.5.3.p.1">The server understood the request, but refuses to authorize it. Providing different user authentication credentials might
    25232653         be successful, but any credentials that were provided in the request are insufficient. The request <em class="bcp14">SHOULD NOT</em> be repeated with the same credentials.
    25242654      </p>
    2525       <p id="rfc.section.6.5.3.p.2">If the request method was not HEAD and the server wishes to make public why the request has not been fulfilled, it <em class="bcp14">SHOULD</em> describe the reason for the refusal in the representation. If the server does not wish to make this information available
     2655      <p id="rfc.section.7.5.3.p.2">If the request method was not HEAD and the server wishes to make public why the request has not been fulfilled, it <em class="bcp14">SHOULD</em> describe the reason for the refusal in the representation. If the server does not wish to make this information available
    25262656         to the client, the status code <a href="#status.404" class="smpl">404
    25272657            (Not Found)</a>  <em class="bcp14">MAY</em> be used instead.
    25282658      </p>
    2529       <div id="rfc.iref.57"></div>
    2530       <h3 id="rfc.section.6.5.4"><a href="#rfc.section.6.5.4">6.5.4</a>&nbsp;<a id="status.404" href="#status.404">404 Not Found</a></h3>
    2531       <p id="rfc.section.6.5.4.p.1">The server has not found anything matching the effective request URI. No indication is given of whether the condition is temporary
     2659      <div id="rfc.iref.71"></div>
     2660      <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>
     2661      <p id="rfc.section.7.5.4.p.1">The server has not found anything matching the effective request URI. No indication is given of whether the condition is temporary
    25322662         or permanent. The <a href="#status.410" class="smpl">410 (Gone)</a> status code <em class="bcp14">SHOULD</em> be used if the server knows, through some internally configurable mechanism, that an old resource is permanently unavailable
    25332663         and has no forwarding address. This status code is commonly used when the server does not wish to reveal exactly why the request
    25342664         has been refused, or when no other response is applicable.
    25352665      </p>
    2536       <div id="rfc.iref.57"></div>
    2537       <h3 id="rfc.section.6.5.5"><a href="#rfc.section.6.5.5">6.5.5</a>&nbsp;<a id="status.405" href="#status.405">405 Method Not Allowed</a></h3>
    2538       <p id="rfc.section.6.5.5.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.
    2539       </p>
    2540       <div id="rfc.iref.57"></div>
    2541       <h3 id="rfc.section.6.5.6"><a href="#rfc.section.6.5.6">6.5.6</a>&nbsp;<a id="status.406" href="#status.406">406 Not Acceptable</a></h3>
    2542       <p id="rfc.section.6.5.6.p.1">The resource identified by the request is only capable of generating response representations which have content characteristics
     2666      <div id="rfc.iref.71"></div>
     2667      <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>
     2668      <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.
     2669      </p>
     2670      <div id="rfc.iref.71"></div>
     2671      <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>
     2672      <p id="rfc.section.7.5.6.p.1">The resource identified by the request is only capable of generating response representations which have content characteristics
    25432673         not acceptable according to the <a href="#header.accept" class="smpl">Accept</a> and Accept-* header fields sent in the request.
    25442674      </p>
    2545       <p id="rfc.section.6.5.6.p.2">Unless it was a HEAD request, the response <em class="bcp14">SHOULD</em> include a representation containing a list of available representation characteristics and location(s) from which the user
     2675      <p id="rfc.section.7.5.6.p.2">Unless it was a HEAD request, the response <em class="bcp14">SHOULD</em> include a representation containing a list of available representation characteristics and location(s) from which the user
    25462676         or user agent can choose the one most appropriate. Depending upon the format and the capabilities of the user agent, selection
    25472677         of the most appropriate choice <em class="bcp14">MAY</em> be performed automatically. However, this specification does not define any standard for such automatic selection.
    25482678      </p>
    2549       <div class="note" id="rfc.section.6.5.6.p.3">
     2679      <div class="note" id="rfc.section.7.5.6.p.3">
    25502680         <p> <b>Note:</b> HTTP/1.1 servers are allowed to return responses which are not acceptable according to the accept header fields sent in the
    25512681            request. In some cases, this might even be preferable to sending a 406 response. User agents are encouraged to inspect the
    … …  
    25532683         </p>
    25542684      </div>
    2555       <p id="rfc.section.6.5.6.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.
    2556       </p>
    2557       <div id="rfc.iref.57"></div>
    2558       <h3 id="rfc.section.6.5.7"><a href="#rfc.section.6.5.7">6.5.7</a>&nbsp;<a id="status.408" href="#status.408">408 Request Timeout</a></h3>
    2559       <p id="rfc.section.6.5.7.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.
    2560       </p>
    2561       <div id="rfc.iref.57"></div>
    2562       <h3 id="rfc.section.6.5.8"><a href="#rfc.section.6.5.8">6.5.8</a>&nbsp;<a id="status.409" href="#status.409">409 Conflict</a></h3>
    2563       <p id="rfc.section.6.5.8.p.1">The request could not be completed due to a conflict with the current state of the resource. This code is only allowed in
     2685      <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.
     2686      </p>
     2687      <div id="rfc.iref.71"></div>
     2688      <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>
     2689      <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.
     2690      </p>
     2691      <div id="rfc.iref.71"></div>
     2692      <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>
     2693      <p id="rfc.section.7.5.8.p.1">The request could not be completed due to a conflict with the current state of the resource. This code is only allowed in
    25642694         situations where it is expected that the user might be able to resolve the conflict and resubmit the request. The payload <em class="bcp14">SHOULD</em> include enough information for the user to recognize the source of the conflict. Ideally, the response representation would
    25652695         include enough information for the user or user agent to fix the problem; however, that might not be possible and is not required.
    25662696      </p>
    2567       <p id="rfc.section.6.5.8.p.2">Conflicts are most likely to occur in response to a PUT request. For example, if versioning were being used and the representation
     2697      <p id="rfc.section.7.5.8.p.2">Conflicts are most likely to occur in response to a PUT request. For example, if versioning were being used and the representation
    25682698         being PUT included changes to a resource which conflict with those made by an earlier (third-party) request, the server might
    25692699         use the 409 response to indicate that it can't complete the request. In this case, the response representation would likely
    25702700         contain a list of the differences between the two versions.
    25712701      </p>
    2572       <div id="rfc.iref.57"></div>
    2573       <h3 id="rfc.section.6.5.9"><a href="#rfc.section.6.5.9">6.5.9</a>&nbsp;<a id="status.410" href="#status.410">410 Gone</a></h3>
    2574       <p id="rfc.section.6.5.9.p.1">The target resource is no longer available at the server and no forwarding address is known. This condition is expected to
     2702      <div id="rfc.iref.71"></div>
     2703      <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>
     2704      <p id="rfc.section.7.5.9.p.1">The target resource is no longer available at the server and no forwarding address is known. This condition is expected to
    25752705         be considered permanent. Clients with link editing capabilities <em class="bcp14">SHOULD</em> delete references to the effective request URI after user approval. If the server does not know, or has no facility to determine,
    25762706         whether or not the condition is permanent, the status code <a href="#status.404" class="smpl">404 (Not Found)</a>  <em class="bcp14">SHOULD</em> be used instead.
    25772707      </p>
    2578       <p id="rfc.section.6.5.9.p.2">The 410 response is primarily intended to assist the task of web maintenance by notifying the recipient that the resource
     2708      <p id="rfc.section.7.5.9.p.2">The 410 response is primarily intended to assist the task of web maintenance by notifying the recipient that the resource
    25792709         is intentionally unavailable and that the server owners desire that remote links to that resource be removed. Such an event
    25802710         is common for limited-time, promotional services and for resources belonging to individuals no longer working at the server's
    … …  
    25822712         — that is left to the discretion of the server owner.
    25832713      </p>
    2584       <p id="rfc.section.6.5.9.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.Part6.14"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 410 responses.
    2585       </p>
    2586       <div id="rfc.iref.57"></div>
    2587       <h3 id="rfc.section.6.5.10"><a href="#rfc.section.6.5.10">6.5.10</a>&nbsp;<a id="status.411" href="#status.411">411 Length Required</a></h3>
    2588       <p id="rfc.section.6.5.10.p.1">The server refuses to accept the request without a defined <a href="p1-messaging.html#header.content-length" class="smpl">Content-Length</a>. The client <em class="bcp14">MAY</em> repeat the request if it adds a valid Content-Length header field containing the length of the message body in the request
     2714      <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.Part6.14"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) to determine freshness for 410 responses.
     2715      </p>
     2716      <div id="rfc.iref.71"></div>
     2717      <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>
     2718      <p id="rfc.section.7.5.10.p.1">The server refuses to accept the request without a defined <a href="p1-messaging.html#header.content-length" class="smpl">Content-Length</a>. The client <em class="bcp14">MAY</em> repeat the request if it adds a valid Content-Length header field containing the length of the message body in the request
    25892719         message.
    25902720      </p>
    2591       <div id="rfc.iref.57"></div>
    2592       <h3 id="rfc.section.6.5.11"><a href="#rfc.section.6.5.11">6.5.11</a>&nbsp;<a id="status.413" href="#status.413">413 Request Representation Too Large</a></h3>
    2593       <p id="rfc.section.6.5.11.p.1">The server is refusing to process a request because the request representation is larger than the server is willing or able
     2721      <div id="rfc.iref.71"></div>
     2722      <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>
     2723      <p id="rfc.section.7.5.11.p.1">The server is refusing to process a request because the request representation is larger than the server is willing or able
    25942724         to process. The server <em class="bcp14">MAY</em> close the connection to prevent the client from continuing the request.
    25952725      </p>
    2596       <p id="rfc.section.6.5.11.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.
    2597       </p>
    2598       <div id="rfc.iref.57"></div>
    2599       <h3 id="rfc.section.6.5.12"><a href="#rfc.section.6.5.12">6.5.12</a>&nbsp;<a id="status.414" href="#status.414">414 URI Too Long</a></h3>
    2600       <p id="rfc.section.6.5.12.p.1">The server is refusing to service the request because the effective request URI is longer than the server is willing to interpret.
     2726      <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.
     2727      </p>
     2728      <div id="rfc.iref.71"></div>
     2729      <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>
     2730      <p id="rfc.section.7.5.12.p.1">The server is refusing to service the request because the effective request URI is longer than the server is willing to interpret.
    26012731         This rare condition is only likely to occur when a client has improperly converted a POST request to a GET request with long
    26022732         query information, when the client has descended into a URI "black hole" of redirection (e.g., a redirected URI prefix that
    … …  
    26042734         in some servers using fixed-length buffers for reading or manipulating the request-target.
    26052735      </p>
    2606       <div id="rfc.iref.57"></div>
    2607       <h3 id="rfc.section.6.5.13"><a href="#rfc.section.6.5.13">6.5.13</a>&nbsp;<a id="status.415" href="#status.415">415 Unsupported Media Type</a></h3>
    2608       <p id="rfc.section.6.5.13.p.1">The server is refusing to service the request because the request payload is in a format not supported by this request method
     2736      <div id="rfc.iref.71"></div>
     2737      <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>
     2738      <p id="rfc.section.7.5.13.p.1">The server is refusing to service the request because the request payload is in a format not supported by this request method
    26092739         on the target resource.
    26102740      </p>
    2611       <div id="rfc.iref.57"></div>
    2612       <h3 id="rfc.section.6.5.14"><a href="#rfc.section.6.5.14">6.5.14</a>&nbsp;<a id="status.417" href="#status.417">417 Expectation Failed</a></h3>
    2613       <p id="rfc.section.6.5.14.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;5.1.2</a>) could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could
     2741      <div id="rfc.iref.71"></div>
     2742      <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>
     2743      <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
    26142744         not be met by the next-hop server.
    26152745      </p>
    2616       <div id="rfc.iref.57"></div>
    2617       <h3 id="rfc.section.6.5.15"><a href="#rfc.section.6.5.15">6.5.15</a>&nbsp;<a id="status.426" href="#status.426">426 Upgrade Required</a></h3>
    2618       <p id="rfc.section.6.5.15.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 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.21"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) specifying the required protocols.
    2619       </p>
    2620       <div id="rfc.figure.u.33"></div>
     2746      <div id="rfc.iref.71"></div>
     2747      <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>
     2748      <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 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.24"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) specifying the required protocols.
     2749      </p>
     2750      <div id="rfc.figure.u.41"></div>
    26212751      <p>Example:</p>  <pre class="text">HTTP/1.1 426 Upgrade Required
    26222752Upgrade: HTTP/3.0
    … …  
    26262756
    26272757<span id="s426body">This service requires use of the HTTP/3.0 protocol.
    2628 </span></pre><p id="rfc.section.6.5.15.p.3">The server <em class="bcp14">SHOULD</em> include a message body in the 426 response which indicates in human readable form the reason for the error and describes any
     2758</span></pre><p id="rfc.section.7.5.15.p.3">The server <em class="bcp14">SHOULD</em> include a message body in the 426 response which indicates in human readable form the reason for the error and describes any
    26292759         alternative courses which might be available to the user.
    26302760      </p>
    2631       <h2 id="rfc.section.6.6"><a href="#rfc.section.6.6">6.6</a>&nbsp;<a id="status.5xx" href="#status.5xx">Server Error 5xx</a></h2>
    2632       <div id="rfc.iref.57"></div>
     2761      <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>
     2762      <div id="rfc.iref.71"></div>
    26332763      <div id="rfc.iref.s.6"></div>
    2634       <p id="rfc.section.6.6.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
     2764      <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
    26352765         of performing the request. Except when responding to a HEAD request, the server <em class="bcp14">SHOULD</em> include a representation containing an explanation of the error situation, and whether it is a temporary or permanent condition.
    26362766         User agents <em class="bcp14">SHOULD</em> display any included representation to the user. These response codes are applicable to any request method.
    26372767      </p>
    2638       <div id="rfc.iref.58"></div>
    2639       <h3 id="rfc.section.6.6.1"><a href="#rfc.section.6.6.1">6.6.1</a>&nbsp;<a id="status.500" href="#status.500">500 Internal Server Error</a></h3>
    2640       <p id="rfc.section.6.6.1.p.1">The server encountered an unexpected condition which prevented it from fulfilling the request.</p>
    2641       <div id="rfc.iref.58"></div>
    2642       <h3 id="rfc.section.6.6.2"><a href="#rfc.section.6.6.2">6.6.2</a>&nbsp;<a id="status.501" href="#status.501">501 Not Implemented</a></h3>
    2643       <p id="rfc.section.6.6.2.p.1">The server does not support the functionality required to fulfill the request. This is the appropriate response when the server
     2768      <div id="rfc.iref.72"></div>
     2769      <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>
     2770      <p id="rfc.section.7.6.1.p.1">The server encountered an unexpected condition which prevented it from fulfilling the request.</p>
     2771      <div id="rfc.iref.72"></div>
     2772      <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>
     2773      <p id="rfc.section.7.6.2.p.1">The server does not support the functionality required to fulfill the request. This is the appropriate response when the server
    26442774         does not recognize the request method and is not capable of supporting it for any resource.
    26452775      </p>
    2646       <div id="rfc.iref.58"></div>
    2647       <h3 id="rfc.section.6.6.3"><a href="#rfc.section.6.6.3">6.6.3</a>&nbsp;<a id="status.502" href="#status.502">502 Bad Gateway</a></h3>
    2648       <p id="rfc.section.6.6.3.p.1">The server, while acting as a gateway or proxy, received an invalid response from the upstream server it accessed in attempting
     2776      <div id="rfc.iref.72"></div>
     2777      <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>
     2778      <p id="rfc.section.7.6.3.p.1">The server, while acting as a gateway or proxy, received an invalid response from the upstream server it accessed in attempting
    26492779         to fulfill the request.
    26502780      </p>
    2651       <div id="rfc.iref.58"></div>
    2652       <h3 id="rfc.section.6.6.4"><a href="#rfc.section.6.6.4">6.6.4</a>&nbsp;<a id="status.503" href="#status.503">503 Service Unavailable</a></h3>
    2653       <p id="rfc.section.6.6.4.p.1">The server is currently unable to handle the request due to a temporary overloading or maintenance of the server.</p>
    2654       <p id="rfc.section.6.6.4.p.2">The implication is that this is a temporary condition which will be alleviated after some delay. If known, the length of the
    2655          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;7.1.3</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
     2781      <div id="rfc.iref.72"></div>
     2782      <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>
     2783      <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>
     2784      <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
     2785         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;8.1.3</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
    26562786            Server Error)</a> response.
    26572787      </p>
    2658       <div class="note" id="rfc.section.6.6.4.p.3">
     2788      <div class="note" id="rfc.section.7.6.4.p.3">
    26592789         <p> <b>Note:</b> The existence of the 503 status code does not imply that a server has to use it when becoming overloaded. Some servers might
    26602790            wish to simply refuse the connection.
    26612791         </p>
    26622792      </div>
    2663       <div id="rfc.iref.58"></div>
    2664       <h3 id="rfc.section.6.6.5"><a href="#rfc.section.6.6.5">6.6.5</a>&nbsp;<a id="status.504" href="#status.504">504 Gateway Timeout</a></h3>
    2665       <p id="rfc.section.6.6.5.p.1">The server, while acting as a gateway or proxy, did not receive a timely response from the upstream server specified by the
     2793      <div id="rfc.iref.72"></div>
     2794      <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>
     2795      <p id="rfc.section.7.6.5.p.1">The server, while acting as a gateway or proxy, did not receive a timely response from the upstream server specified by the
    26662796         URI (e.g., HTTP, FTP, LDAP) or some other auxiliary server (e.g., DNS) it needed to access in attempting to complete the request.
    26672797      </p>
    2668       <div class="note" id="rfc.section.6.6.5.p.2">
     2798      <div class="note" id="rfc.section.7.6.5.p.2">
    26692799         <p> <b>Note</b> to implementers: some deployed proxies are known to return <a href="#status.400" class="smpl">400 (Bad Request)</a> or <a href="#status.500" class="smpl">500 (Internal Server
    26702800               Error)</a> when DNS lookups time out.
    26712801         </p>
    26722802      </div>
    2673       <div id="rfc.iref.58"></div>
    2674       <h3 id="rfc.section.6.6.6"><a href="#rfc.section.6.6.6">6.6.6</a>&nbsp;<a id="status.505" href="#status.505">505 HTTP Version Not Supported</a></h3>
    2675       <p id="rfc.section.6.6.6.p.1">The server does not support, or refuses to support, the protocol version that was used in the request message. The server
     2803      <div id="rfc.iref.72"></div>
     2804      <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>
     2805      <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
    26762806         is indicating that it is unable or unwilling to complete the request using the same major version as the client, as described
    2677          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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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.
    2678       </p>
    2679       <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a id="response.header.fields" href="#response.header.fields">Response Header Fields</a></h1>
    2680       <p id="rfc.section.7.p.1">The response header fields allow the server to pass additional information about the response which cannot be placed in the
    2681          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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>).
    2682       </p>
    2683       <h2 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1</a>&nbsp;<a id="response.control.data" href="#response.control.data">Control Data</a></h2>
    2684       <p id="rfc.section.7.1.p.1">Response header fields can supply control data that supplements the status code or instructs the client where to go next.</p>
     2807         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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[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.
     2808      </p>
     2809      <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>
     2810      <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
     2811         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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>).
     2812      </p>
     2813      <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>
     2814      <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>
    26852815      <div id="rfc.table.u.10">
    26862816         <table class="tt full left" cellpadding="3" cellspacing="0">
    … …  
    26982828               <tr>
    26992829                  <td class="left">Date</td>
    2700                   <td class="left"><a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section&nbsp;7.1.1</a></td>
     2830                  <td class="left"><a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section&nbsp;8.1.1.2</a></td>
    27012831               </tr>
    27022832               <tr>
    27032833                  <td class="left">Location</td>
    2704                   <td class="left"><a href="#header.location" id="rfc.xref.header.location.3" title="Location">Section&nbsp;7.1.2</a></td>
     2834                  <td class="left"><a href="#header.location" id="rfc.xref.header.location.3" title="Location">Section&nbsp;8.1.2</a></td>
    27052835               </tr>
    27062836               <tr>
    27072837                  <td class="left">Retry-After</td>
    2708                   <td class="left"><a href="#header.retry-after" id="rfc.xref.header.retry-after.2" title="Retry-After">Section&nbsp;7.1.3</a></td>
     2838                  <td class="left"><a href="#header.retry-after" id="rfc.xref.header.retry-after.2" title="Retry-After">Section&nbsp;8.1.3</a></td>
    27092839               </tr>
    27102840            </tbody>
    27112841         </table>
    27122842      </div>
    2713       <div id="rfc.iref.d.2"></div>
    2714       <h3 id="rfc.section.7.1.1"><a href="#rfc.section.7.1.1">7.1.1</a>&nbsp;<a id="header.date" href="#header.date">Date</a></h3>
    2715       <p id="rfc.section.7.1.1.p.1">The "Date" header field represents the date and time at which the message was originated, having the same semantics as the
    2716          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;8.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.
    2717       </p>
    2718       <div id="rfc.figure.u.34"></div><pre class="inline"><span id="rfc.iref.g.27"></span>  <a href="#header.date" class="smpl">Date</a> = <a href="#http.date" class="smpl">HTTP-date</a>
    2719 </pre><p id="rfc.section.7.1.1.p.3">An example is</p>
    2720       <div id="rfc.figure.u.35"></div><pre class="text">  Date: Tue, 15 Nov 1994 08:12:31 GMT
    2721 </pre><p id="rfc.section.7.1.1.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:
    2722       </p>
    2723       <ol>
    2724          <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.
    2725          </li>
    2726          <li>If the response status code conveys a server error, e.g., <a href="#status.500" class="smpl">500
    2727                (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.
    2728          </li>
    2729          <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.
    2730          </li>
    2731       </ol>
    2732       <p id="rfc.section.7.1.1.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.
    2733       </p>
    2734       <p id="rfc.section.7.1.1.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
    2735          when it doesn't convey any useful information (as is usually the case for requests that do not contain a payload).
    2736       </p>
    2737       <p id="rfc.section.7.1.1.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
    2738          of generating a reasonably accurate date and time. In theory, the date ought to represent the moment just before the payload
    2739          is generated. In practice, the date can be generated at any time during the message origination without affecting its semantic
    2740          value.
    2741       </p>
    2742       <div id="rfc.iref.l.1"></div>
    2743       <h3 id="rfc.section.7.1.2"><a href="#rfc.section.7.1.2">7.1.2</a>&nbsp;<a id="header.location" href="#header.location">Location</a></h3>
    2744       <p id="rfc.section.7.1.2.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.
    2745       </p>
    2746       <div id="rfc.figure.u.36"></div><pre class="inline"><span id="rfc.iref.g.28"></span>  <a href="#header.location" class="smpl">Location</a> = <a href="#imported.abnf" class="smpl">URI-reference</a>
    2747 </pre><p id="rfc.section.7.1.2.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.
    2748       </p>
    2749       <p id="rfc.section.7.1.2.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,
    2750          then the original URI's fragment identifier is added to the final value.
    2751       </p>
    2752       <div id="rfc.figure.u.37"></div>
    2753       <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
    2754 </pre>  <p>would result in a final value of "http://www.example.org/pub/WWW/People.html#tim"</p>
    2755       <div id="rfc.figure.u.38"></div>
    2756       <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
    2757 </pre>  <p>would result in a final value of "http://www.example.net/index.html#larry", preserving the original fragment identifier.</p>
    2758       <div class="note" id="rfc.section.7.1.2.p.7">
    2759          <p> <b>Note:</b> Some recipients attempt to recover from Location fields that are not valid URI references. This specification does not mandate
    2760             or define such processing, but does allow it.
    2761          </p>
    2762       </div>
    2763       <p id="rfc.section.7.1.2.p.8">There are circumstances in which a fragment identifier in a Location URI would not be appropriate. For instance, when it appears
    2764          in a <a href="#status.201" class="smpl">201
    2765             (Created)</a> response, where the Location header field specifies the URI for the entire created resource.
    2766       </p>
    2767       <div class="note" id="rfc.section.7.1.2.p.9">
    2768          <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;3.1.4</a>) differs from Location in that the Content-Location identifies the most specific resource corresponding to the enclosed representation.
    2769             It is therefore possible for a response to contain header fields for both Location and Content-Location.
    2770          </p>
    2771       </div>
    2772       <div id="rfc.iref.r.3"></div>
    2773       <h3 id="rfc.section.7.1.3"><a href="#rfc.section.7.1.3">7.1.3</a>&nbsp;<a id="header.retry-after" href="#header.retry-after">Retry-After</a></h3>
    2774       <p id="rfc.section.7.1.3.p.1">The header "Retry-After" field can be used with a <a href="#status.503" class="smpl">503 (Service
    2775             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.
    2776       </p>
    2777       <p id="rfc.section.7.1.3.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>
    2778       <div id="rfc.figure.u.39"></div><pre class="inline"><span id="rfc.iref.g.29"></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>
    2779 </pre><div id="rule.delta-seconds">
    2780          <p id="rfc.section.7.1.3.p.4">  Time spans are non-negative decimal integers, representing time in seconds.</p>
    2781       </div>
    2782       <div id="rfc.figure.u.40"></div><pre class="inline"><span id="rfc.iref.g.30"></span>  <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>  = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
    2783 </pre><p id="rfc.section.7.1.3.p.6">Two examples of its use are</p>
    2784       <div id="rfc.figure.u.41"></div><pre class="text">  Retry-After: Fri, 31 Dec 1999 23:59:59 GMT
    2785   Retry-After: 120
    2786 </pre><p id="rfc.section.7.1.3.p.8">In the latter example, the delay is 2 minutes.</p>
    2787       <h2 id="rfc.section.7.2"><a href="#rfc.section.7.2">7.2</a>&nbsp;<a id="selected.representation" href="#selected.representation">Selected Representation Header Fields</a></h2>
    2788       <p id="rfc.section.7.2.p.1"><span id="rfc.iref.s.7"></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
    2789          the same request had used the method GET and excluded any conditional request header fields.
    2790       </p>
    2791       <p id="rfc.section.7.2.p.2">Additional header fields define metadata about the selected representation, which might differ from the representation included
    2792          in the message for responses to some state-changing methods. The following header fields are defined as selected representation
    2793          metadata:
    2794       </p>
    2795       <div id="rfc.table.u.11">
    2796          <table class="tt full left" cellpadding="3" cellspacing="0">
    2797             <thead>
    2798                <tr>
    2799                   <th>Header Field Name</th>
    2800                   <th>Defined in...</th>
    2801                </tr>
    2802             </thead>
    2803             <tbody>
    2804                <tr>
    2805                   <td class="left">ETag</td>
    2806                   <td class="left"><a href="p4-conditional.html#header.etag" title="ETag">Section 2.3</a> of <a href="#Part4" id="rfc.xref.Part4.12"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a></td>
    2807                </tr>
    2808                <tr>
    2809                   <td class="left">Last-Modified</td>
    2810                   <td class="left"><a href="p4-conditional.html#header.last-modified" title="Last-Modified">Section 2.2</a> of <a href="#Part4" id="rfc.xref.Part4.13"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a></td>
    2811                </tr>
    2812                <tr>
    2813                   <td class="left">Vary</td>
    2814                   <td class="left"><a href="#header.vary" id="rfc.xref.header.vary.2" title="Vary">Section&nbsp;7.2.1</a></td>
    2815                </tr>
    2816             </tbody>
    2817          </table>
    2818       </div>
    2819       <div id="rfc.iref.v.1"></div>
    2820       <h3 id="rfc.section.7.2.1"><a href="#rfc.section.7.2.1">7.2.1</a>&nbsp;<a id="header.vary" href="#header.vary">Vary</a></h3>
    2821       <p id="rfc.section.7.2.1.p.1">The "Vary" header field conveys the set of header fields that were used to select the representation.</p>
    2822       <p id="rfc.section.7.2.1.p.2">Caches use this information as part of determining whether a stored response can be used to satisfy a given request (<a href="p6-cache.html#caching.negotiated.responses" title="Using Negotiated Responses">Section 4.3</a> of <a href="#Part6" id="rfc.xref.Part6.16"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>).
    2823       </p>
    2824       <p id="rfc.section.7.2.1.p.3">In uncacheable or stale responses, the Vary field value advises the user agent about the criteria that were used to select
    2825          the representation.
    2826       </p>
    2827       <div id="rfc.figure.u.42"></div><pre class="inline"><span id="rfc.iref.g.31"></span>  <a href="#header.vary" class="smpl">Vary</a> = "*" / 1#<a href="#imported.abnf" class="smpl">field-name</a>
    2828 </pre><p id="rfc.section.7.2.1.p.5">The set of header fields named by the Vary field value is known as the selecting header fields.</p>
    2829       <p id="rfc.section.7.2.1.p.6">A server <em class="bcp14">SHOULD</em> include a Vary header field with any cacheable response that is subject to proactive negotiation. Doing so allows a cache
    2830          to properly interpret future requests on that resource and informs the user agent about the presence of negotiation on that
    2831          resource. A server <em class="bcp14">MAY</em> include a Vary header field with a non-cacheable response that is subject to proactive negotiation, since this might provide
    2832          the user agent with useful information about the dimensions over which the response varies at the time of the response.
    2833       </p>
    2834       <p id="rfc.section.7.2.1.p.7">A Vary field value of "*" signals that unspecified parameters not limited to the header fields (e.g., the network address
    2835          of the client), play a role in the selection of the response representation; therefore, a cache cannot determine whether this
    2836          response is appropriate. A proxy <em class="bcp14">MUST NOT</em> generate the "*" value.
    2837       </p>
    2838       <p id="rfc.section.7.2.1.p.8">The field-names given are not limited to the set of standard header fields defined by this specification. Field names are
    2839          case-insensitive.
    2840       </p>
    2841       <h2 id="rfc.section.7.3"><a href="#rfc.section.7.3">7.3</a>&nbsp;<a id="response.auth" href="#response.auth">Authentication Challenges</a></h2>
    2842       <p id="rfc.section.7.3.p.1">Authentication challenges indicate what mechanisms are available for the client to provide authentication credentials in future
    2843          requests.
    2844       </p>
    2845       <div id="rfc.table.u.12">
    2846          <table class="tt full left" cellpadding="3" cellspacing="0">
    2847             <thead>
    2848                <tr>
    2849                   <th>Header Field Name</th>
    2850                   <th>Defined in...</th>
    2851                </tr>
    2852             </thead>
    2853             <tbody>
    2854                <tr>
    2855                   <td class="left">WWW-Authenticate</td>
    2856                   <td class="left"><a href="p7-auth.html#header.www-authenticate" title="WWW-Authenticate">Section 4.4</a> of <a href="#Part7" id="rfc.xref.Part7.6"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Authentication">[Part7]</cite></a></td>
    2857                </tr>
    2858                <tr>
    2859                   <td class="left">Proxy-Authenticate</td>
    2860                   <td class="left"><a href="p7-auth.html#header.proxy-authenticate" title="Proxy-Authenticate">Section 4.2</a> of <a href="#Part7" id="rfc.xref.Part7.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Authentication">[Part7]</cite></a></td>
    2861                </tr>
    2862             </tbody>
    2863          </table>
    2864       </div>
    2865       <h2 id="rfc.section.7.4"><a href="#rfc.section.7.4">7.4</a>&nbsp;<a id="response.inform" href="#response.inform">Informative</a></h2>
    2866       <p id="rfc.section.7.4.p.1">The remaining response header fields provide more information about the target resource for potential use in later requests.</p>
    2867       <div id="rfc.table.u.13">
    2868          <table class="tt full left" cellpadding="3" cellspacing="0">
    2869             <thead>
    2870                <tr>
    2871                   <th>Header Field Name</th>
    2872                   <th>Defined in...</th>
    2873                </tr>
    2874             </thead>
    2875             <tbody>
    2876                <tr>
    2877                   <td class="left">Accept-Ranges</td>
    2878                   <td class="left"><a href="p5-range.html#header.accept-ranges" title="Accept-Ranges">Section 5.1</a> of <a href="#Part5" id="rfc.xref.Part5.10"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a></td>
    2879                </tr>
    2880                <tr>
    2881                   <td class="left">Allow</td>
    2882                   <td class="left"><a href="#header.allow" id="rfc.xref.header.allow.2" title="Allow">Section&nbsp;7.4.1</a></td>
    2883                </tr>
    2884                <tr>
    2885                   <td class="left">Server</td>
    2886                   <td class="left"><a href="#header.server" id="rfc.xref.header.server.1" title="Server">Section&nbsp;7.4.2</a></td>
    2887                </tr>
    2888             </tbody>
    2889          </table>
    2890       </div>
    2891       <div id="rfc.iref.a.5"></div>
    2892       <h3 id="rfc.section.7.4.1"><a href="#rfc.section.7.4.1">7.4.1</a>&nbsp;<a id="header.allow" href="#header.allow">Allow</a></h3>
    2893       <p id="rfc.section.7.4.1.p.1">The "Allow" header field lists the set of methods advertised as supported by the target resource. The purpose of this field
    2894          is strictly to inform the recipient of valid request methods associated with the resource.
    2895       </p>
    2896       <div id="rfc.figure.u.43"></div><pre class="inline"><span id="rfc.iref.g.32"></span>  <a href="#header.allow" class="smpl">Allow</a> = #<a href="#method.overview" class="smpl">method</a>
    2897 </pre><p id="rfc.section.7.4.1.p.3">Example of use:</p>
    2898       <div id="rfc.figure.u.44"></div><pre class="text">  Allow: GET, HEAD, PUT
    2899 </pre><p id="rfc.section.7.4.1.p.5">The actual set of allowed methods is defined by the origin server at the time of each request.</p>
    2900       <p id="rfc.section.7.4.1.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
    2901          to the generic message handling rules.
    2902       </p>
    2903       <div id="rfc.iref.s.8"></div>
    2904       <h3 id="rfc.section.7.4.2"><a href="#rfc.section.7.4.2">7.4.2</a>&nbsp;<a id="header.server" href="#header.server">Server</a></h3>
    2905       <p id="rfc.section.7.4.2.p.1">The "Server" header field contains information about the software used by the origin server to handle the request.</p>
    2906       <p id="rfc.section.7.4.2.p.2">The field can contain multiple product tokens (<a href="#product.tokens" title="Product Tokens">Section&nbsp;8.2</a>) and comments (<a href="p1-messaging.html#header.fields" title="Header Fields">Section 3.2</a> of <a href="#Part1" id="rfc.xref.Part1.24"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) identifying the server and any significant subproducts. The product tokens are listed in order of their significance for
    2907          identifying the application.
    2908       </p>
    2909       <div id="rfc.figure.u.45"></div><pre class="inline"><span id="rfc.iref.g.33"></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> ) )
    2910 </pre><p id="rfc.section.7.4.2.p.4">Example:</p>
    2911       <div id="rfc.figure.u.46"></div><pre class="text">  Server: CERN/3.0 libwww/2.17
    2912 </pre><p id="rfc.section.7.4.2.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.Part1.25"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>).
    2913       </p>
    2914       <div class="note" id="rfc.section.7.4.2.p.7">
    2915          <p> <b>Note:</b> Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks
    2916             against software that is known to contain security holes. Server implementers are encouraged to make this field a configurable
    2917             option.
    2918          </p>
    2919       </div>
    2920       <h1 id="rfc.section.8"><a href="#rfc.section.8">8.</a>&nbsp;<a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h1>
    2921       <h2 id="rfc.section.8.1"><a href="#rfc.section.8.1">8.1</a>&nbsp;<a id="http.date" href="#http.date">Date/Time Formats</a></h2>
    2922       <p id="rfc.section.8.1.p.1">HTTP applications have historically allowed three different formats for date/time stamps. However, the preferred format is
     2843      <h3 id="rfc.section.8.1.1"><a href="#rfc.section.8.1.1">8.1.1</a>&nbsp;<a id="origination.date" href="#origination.date">Origination Date</a></h3>
     2844      <h4 id="rfc.section.8.1.1.1"><a href="#rfc.section.8.1.1.1">8.1.1.1</a>&nbsp;<a id="http.date" href="#http.date">Date/Time Formats</a></h4>
     2845      <p id="rfc.section.8.1.1.1.p.1">HTTP applications have historically allowed three different formats for date/time stamps. However, the preferred format is
    29232846         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>:
    29242847      </p>
    2925       <div id="rfc.figure.u.47"></div><pre class="text">Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
    2926 </pre><p id="rfc.section.8.1.p.3">The other formats are described here only for compatibility with obsolete implementations.</p>
    2927       <div id="rfc.figure.u.48"></div><pre class="text">Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format
     2848      <div id="rfc.figure.u.42"></div><pre class="text">Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
     2849</pre><p id="rfc.section.8.1.1.1.p.3">The other formats are described here only for compatibility with obsolete implementations.</p>
     2850      <div id="rfc.figure.u.43"></div><pre class="text">Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format
    29282851Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format
    2929 </pre><p id="rfc.section.8.1.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.
    2930       </p>
    2931       <p id="rfc.section.8.1.p.6">All HTTP date/time stamps <em class="bcp14">MUST</em> be represented in Greenwich Mean Time (GMT), without exception. For the purposes of HTTP, GMT is exactly equal to UTC (Coordinated
     2852</pre><p id="rfc.section.8.1.1.1.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.
     2853      </p>
     2854      <p id="rfc.section.8.1.1.1.p.6">All HTTP date/time stamps <em class="bcp14">MUST</em> be represented in Greenwich Mean Time (GMT), without exception. For the purposes of HTTP, GMT is exactly equal to UTC (Coordinated
    29322855         Universal Time). This is indicated in the first two formats by the inclusion of "GMT" as the three-letter abbreviation for
    29332856         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.
    29342857      </p>
    2935       <div id="rfc.figure.u.49"></div><pre class="inline"><span id="rfc.iref.g.34"></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>
     2858      <div id="rfc.figure.u.44"></div><pre class="inline"><span id="rfc.iref.g.39"></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>
    29362859</pre><div id="preferred.date.format">
    2937          <p id="rfc.section.8.1.p.8">                    Preferred format:</p>
     2860         <p id="rfc.section.8.1.1.1.p.8">                    Preferred format:</p>
    29382861      </div>
    2939       <div id="rfc.figure.u.50"></div><pre class="inline"><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><span id="rfc.iref.g.46"></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>
     2862      <div id="rfc.figure.u.45"></div><pre class="inline"><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><span id="rfc.iref.g.46"></span><span id="rfc.iref.g.47"></span><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>  <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>
    29402863  ; fixed length subset of the format defined in
    29412864  ; <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>
    … …  
    29752898  <a href="#preferred.date.format" class="smpl">minute</a>       = 2<a href="#imported.abnf" class="smpl">DIGIT</a>               
    29762899  <a href="#preferred.date.format" class="smpl">second</a>       = 2<a href="#imported.abnf" class="smpl">DIGIT</a>               
    2977 </pre><p id="rfc.section.8.1.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>).
     2900</pre><p id="rfc.section.8.1.1.1.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.RFC5322.3"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.3">Section 3.3</a>).
    29782901      </p>
    29792902      <div id="obsolete.date.formats">
    2980          <p id="rfc.section.8.1.p.11">              Obsolete formats:</p>
     2903         <p id="rfc.section.8.1.1.1.p.11">              Obsolete formats:</p>
    29812904      </div>
    2982       <div id="rfc.figure.u.51"></div><pre class="inline"><span id="rfc.iref.g.47"></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>
    2983 </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">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>
     2905      <div id="rfc.figure.u.46"></div><pre class="inline"><span id="rfc.iref.g.52"></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>
     2906</pre><div id="rfc.figure.u.47"></div><pre class="inline"><span id="rfc.iref.g.53"></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>
    29842907  <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>
    29852908                 ; day-month-year (e.g., 02-Jun-82)
    … …  
    29922915         / %x53.61.74.75.72.64.61.79 ; "Saturday", case-sensitive
    29932916         / %x53.75.6E.64.61.79 ; "Sunday", case-sensitive
    2994 </pre><div id="rfc.figure.u.53"></div><pre class="inline"><span id="rfc.iref.g.49"></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>
     2917</pre><div id="rfc.figure.u.48"></div><pre class="inline"><span id="rfc.iref.g.54"></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>
    29952918  <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> ))
    29962919                 ; month day (e.g., Jun  2)
    2997 </pre><div class="note" id="rfc.section.8.1.p.15">
     2920</pre><div class="note" id="rfc.section.8.1.1.1.p.15">
    29982921         <p> <b>Note:</b> Recipients of date values are encouraged to be robust in accepting date values that might have been sent by non-HTTP applications,
    29992922            as is sometimes the case when retrieving or posting messages via proxies/gateways to SMTP or NNTP.
    30002923         </p>
    30012924      </div>
    3002       <div class="note" id="rfc.section.8.1.p.16">
     2925      <div class="note" id="rfc.section.8.1.1.1.p.16">
    30032926         <p> <b>Note:</b> HTTP requirements for the date/time stamp format apply only to their usage within the protocol stream. Clients and servers
    30042927            are not required to use these formats for user presentation, request logging, etc.
    30052928         </p>
    30062929      </div>
    3007       <h2 id="rfc.section.8.2"><a href="#rfc.section.8.2">8.2</a>&nbsp;<a id="product.tokens" href="#product.tokens">Product Tokens</a></h2>
    3008       <p id="rfc.section.8.2.p.1">Product tokens are used to allow communicating applications to identify themselves by software name and version. Most fields
    3009          using product tokens also allow sub-products which form a significant part of the application to be listed, separated by whitespace.
    3010          By convention, the products are listed in order of their significance for identifying the application.
    3011       </p>
    3012       <div id="rfc.figure.u.54"></div><pre class="inline"><span id="rfc.iref.g.50"></span><span id="rfc.iref.g.51"></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>]
    3013   <a href="#product.tokens" class="smpl">product-version</a> = <a href="#imported.abnf" class="smpl">token</a>
    3014 </pre><p id="rfc.section.8.2.p.3">Examples:</p>
    3015       <div id="rfc.figure.u.55"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
    3016   Server: Apache/0.8.4
    3017 </pre><p id="rfc.section.8.2.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).
    3018       </p>
    3019       <h2 id="rfc.section.8.3"><a href="#rfc.section.8.3">8.3</a>&nbsp;<a id="character.sets" href="#character.sets">Character Encodings (charset)</a></h2>
    3020       <p id="rfc.section.8.3.p.1">HTTP uses charset names to indicate the character encoding of a textual representation.</p>
    3021       <div id="rule.charset">
    3022          <p id="rfc.section.8.3.p.2">  A character encoding is identified by a case-insensitive token. The complete set of tokens is defined by the IANA Character
    3023             Set registry (&lt;<a href="http://www.iana.org/assignments/character-sets">http://www.iana.org/assignments/character-sets</a>&gt;).
    3024          </p>
    3025       </div>
    3026       <div id="rfc.figure.u.56"></div><pre class="inline"><span id="rfc.iref.g.52"></span>  <a href="#rule.charset" class="smpl">charset</a> = <a href="#imported.abnf" class="smpl">token</a>
    3027 </pre><p id="rfc.section.8.3.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
    3028          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.
    3029       </p>
    3030       <p id="rfc.section.8.3.p.5">HTTP uses charset in two contexts: within an <a href="#header.accept-charset" class="smpl">Accept-Charset</a> request header field (in which the charset value is an unquoted token) and as the value of a parameter in a <a href="#header.content-type" class="smpl">Content-Type</a> header field (within a request or response), in which case the parameter value of the charset parameter can be quoted.
    3031       </p>
    3032       <p id="rfc.section.8.3.p.6">Implementers need to be aware of IETF character set requirements <a href="#RFC3629" id="rfc.xref.RFC3629.1"><cite title="UTF-8, a transformation format of ISO 10646">[RFC3629]</cite></a>  <a href="#RFC2277" id="rfc.xref.RFC2277.1"><cite title="IETF Policy on Character Sets and Languages">[RFC2277]</cite></a>.
    3033       </p>
    3034       <h2 id="rfc.section.8.4"><a href="#rfc.section.8.4">8.4</a>&nbsp;<a id="content.codings" href="#content.codings">Content Codings</a></h2>
    3035       <p id="rfc.section.8.4.p.1">Content coding values indicate an encoding transformation that has been or can be applied to a representation. Content codings
    3036          are primarily used to allow a representation to be compressed or otherwise usefully transformed without losing the identity
    3037          of its underlying media type and without loss of information. Frequently, the representation is stored in coded form, transmitted
    3038          directly, and only decoded by the recipient.
    3039       </p>
    3040       <div id="rfc.figure.u.57"></div><pre class="inline"><span id="rfc.iref.g.53"></span>  <a href="#content.codings" class="smpl">content-coding</a>   = <a href="#imported.abnf" class="smpl">token</a>
    3041 </pre><p id="rfc.section.8.4.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;5.3.4</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;3.1.2</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding
    3042          mechanism will be required to remove the encoding.
    3043       </p>
    3044       <p id="rfc.section.8.4.p.4">compress<span id="rfc.iref.c.8"></span> 
    3045       </p>
    3046       <ul class="empty">
    3047          <li>See <a href="p1-messaging.html#compress.coding" title="Compress Coding">Section 4.2.1</a> of <a href="#Part1" id="rfc.xref.Part1.26"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>.
    3048          </li>
    3049       </ul>
    3050       <p id="rfc.section.8.4.p.5">deflate<span id="rfc.iref.d.3"></span> 
    3051       </p>
    3052       <ul class="empty">
    3053          <li>See <a href="p1-messaging.html#deflate.coding" title="Deflate Coding">Section 4.2.2</a> of <a href="#Part1" id="rfc.xref.Part1.27"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>.
    3054          </li>
    3055       </ul>
    3056       <p id="rfc.section.8.4.p.6">gzip<span id="rfc.iref.g.54"></span> 
    3057       </p>
    3058       <ul class="empty">
    3059          <li>See <a href="p1-messaging.html#gzip.coding" title="Gzip Coding">Section 4.2.3</a> of <a href="#Part1" id="rfc.xref.Part1.28"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>.
    3060          </li>
    3061       </ul>
    3062       <h2 id="rfc.section.8.5"><a href="#rfc.section.8.5">8.5</a>&nbsp;<a id="media.types" href="#media.types">Media Types</a></h2>
    3063       <p id="rfc.section.8.5.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;3.1.1</a>) and <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section&nbsp;5.3.2</a>) header fields in order to provide open and extensible data typing and type negotiation.
    3064       </p>
    3065       <div id="rfc.figure.u.58"></div><pre class="inline"><span id="rfc.iref.g.55"></span><span id="rfc.iref.g.56"></span><span id="rfc.iref.g.57"></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> )
    3066   <a href="#media.types" class="smpl">type</a>       = <a href="#imported.abnf" class="smpl">token</a>
    3067   <a href="#media.types" class="smpl">subtype</a>    = <a href="#imported.abnf" class="smpl">token</a>
    3068 </pre><div id="rule.parameter">
    3069          <p id="rfc.section.8.5.p.3">      The type/subtype <em class="bcp14">MAY</em> be followed by parameters in the form of attribute/value pairs.
    3070          </p>
    3071       </div>
    3072       <div id="rfc.figure.u.59"></div><pre class="inline"><span id="rfc.iref.g.58"></span><span id="rfc.iref.g.59"></span><span id="rfc.iref.g.60"></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>
    3073   <a href="#rule.parameter" class="smpl">attribute</a>      = <a href="#imported.abnf" class="smpl">token</a>
    3074   <a href="#rule.parameter" class="smpl">value</a>          = <a href="#imported.abnf" class="smpl">word</a>
    3075 </pre><p id="rfc.section.8.5.p.5">The type, subtype, and parameter attribute names are case-insensitive. Parameter values might or might not be case-sensitive,
    3076          depending on the semantics of the parameter name. The presence or absence of a parameter might be significant to the processing
    3077          of a media-type, depending on its definition within the media type registry.
    3078       </p>
    3079       <p id="rfc.section.8.5.p.6">A parameter value that matches the <a href="#imported.abnf" class="smpl">token</a> production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent.
    3080       </p>
    3081       <p id="rfc.section.8.5.p.7">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is
    3082          outlined in <a href="#RFC4288" id="rfc.xref.RFC4288.1"><cite title="Media Type Specifications and Registration Procedures">[RFC4288]</cite></a>. Use of non-registered media types is discouraged.
    3083       </p>
    3084       <h3 id="rfc.section.8.5.1"><a href="#rfc.section.8.5.1">8.5.1</a>&nbsp;<a id="canonicalization.and.text.defaults" href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></h3>
    3085       <p id="rfc.section.8.5.1.p.1">Internet media types are registered with a canonical form. A representation transferred via HTTP messages <em class="bcp14">MUST</em> be in the appropriate canonical form prior to its transmission except for "text" types, as defined in the next paragraph.
    3086       </p>
    3087       <p id="rfc.section.8.5.1.p.2">When in canonical form, media subtypes of the "text" type use CRLF as the text line break. HTTP relaxes this requirement and
    3088          allows the transport of text media with plain CR or LF alone representing a line break when it is done consistently for an
    3089          entire representation. HTTP applications <em class="bcp14">MUST</em> accept CRLF, bare CR, and bare LF as indicating a line break in text media received via HTTP. In addition, if the text is
    3090          in a character encoding that does not use octets 13 and 10 for CR and LF respectively, as is the case for some multi-byte
    3091          character encodings, HTTP allows the use of whatever octet sequences are defined by that character encoding to represent the
    3092          equivalent of CR and LF for line breaks. This flexibility regarding line breaks applies only to text media in the payload
    3093          body; a bare CR or LF <em class="bcp14">MUST NOT</em> be substituted for CRLF within any of the HTTP control structures (such as header fields and multipart boundaries).
    3094       </p>
    3095       <p id="rfc.section.8.5.1.p.3">If a representation is encoded with a content-coding, the underlying data <em class="bcp14">MUST</em> be in a form defined above prior to being encoded.
    3096       </p>
    3097       <h3 id="rfc.section.8.5.2"><a href="#rfc.section.8.5.2">8.5.2</a>&nbsp;<a id="multipart.types" href="#multipart.types">Multipart Types</a></h3>
    3098       <p id="rfc.section.8.5.2.p.1">MIME provides for a number of "multipart" types — encapsulations of one or more representations within a single message body.
    3099          All multipart types share a common syntax, as defined in <a href="http://tools.ietf.org/html/rfc2046#section-5.1.1">Section 5.1.1</a> of <a href="#RFC2046" id="rfc.xref.RFC2046.3"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, and include a boundary parameter as part of the media type value. The message body is itself a protocol element; a sender <em class="bcp14">MUST</em> generate only CRLF to represent line breaks between body-parts.
    3100       </p>
    3101       <p id="rfc.section.8.5.2.p.2">In general, HTTP treats a multipart message body no differently than any other media type: strictly as payload. HTTP does
    3102          not use the multipart boundary as an indicator of message body length.  In all other respects, an HTTP user agent <em class="bcp14">SHOULD</em> follow the same or similar behavior as a MIME user agent would upon receipt of a multipart type. The MIME header fields within
    3103          each body-part of a multipart message body do not have any significance to HTTP beyond that defined by their MIME semantics.
    3104       </p>
    3105       <p id="rfc.section.8.5.2.p.3">A recipient <em class="bcp14">MUST</em> treat an unrecognized multipart subtype as being equivalent to "multipart/mixed".
    3106       </p>
    3107       <div class="note" id="rfc.section.8.5.2.p.4">
    3108          <p> <b>Note:</b> The "multipart/form-data" type has been specifically defined for carrying form data suitable for processing via the POST request
    3109             method, as described in <a href="#RFC2388" id="rfc.xref.RFC2388.1"><cite title="Returning Values from Forms: multipart/form-data">[RFC2388]</cite></a>.
     2930      <div id="rfc.iref.d.3"></div>
     2931      <h4 id="rfc.section.8.1.1.2"><a href="#rfc.section.8.1.1.2">8.1.1.2</a>&nbsp;<a id="header.date" href="#header.date">Date</a></h4>
     2932      <p id="rfc.section.8.1.1.2.p.1">The "Date" header field represents the date and time at which the message was originated, having the same semantics as the
     2933         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.RFC5322.4"><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;8.1.1.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.
     2934      </p>
     2935      <div id="rfc.figure.u.49"></div><pre class="inline"><span id="rfc.iref.g.55"></span>  <a href="#header.date" class="smpl">Date</a> = <a href="#http.date" class="smpl">HTTP-date</a>
     2936</pre><p id="rfc.section.8.1.1.2.p.3">An example is</p>
     2937      <div id="rfc.figure.u.50"></div><pre class="text">  Date: Tue, 15 Nov 1994 08:12:31 GMT
     2938</pre><p id="rfc.section.8.1.1.2.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:
     2939      </p>
     2940      <ol>
     2941         <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.
     2942         </li>
     2943         <li>If the response status code conveys a server error, e.g., <a href="#status.500" class="smpl">500
     2944               (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.
     2945         </li>
     2946         <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.
     2947         </li>
     2948      </ol>
     2949      <p id="rfc.section.8.1.1.2.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.
     2950      </p>
     2951      <p id="rfc.section.8.1.1.2.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
     2952         when it doesn't convey any useful information (as is usually the case for requests that do not contain a payload).
     2953      </p>
     2954      <p id="rfc.section.8.1.1.2.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
     2955         of generating a reasonably accurate date and time. In theory, the date ought to represent the moment just before the payload
     2956         is generated. In practice, the date can be generated at any time during the message origination without affecting its semantic
     2957         value.
     2958      </p>
     2959      <div id="rfc.iref.l.1"></div>
     2960      <h3 id="rfc.section.8.1.2"><a href="#rfc.section.8.1.2">8.1.2</a>&nbsp;<a id="header.location" href="#header.location">Location</a></h3>
     2961      <p id="rfc.section.8.1.2.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.
     2962      </p>
     2963      <div id="rfc.figure.u.51"></div><pre class="inline"><span id="rfc.iref.g.56"></span>  <a href="#header.location" class="smpl">Location</a> = <a href="#imported.abnf" class="smpl">URI-reference</a>
     2964</pre><p id="rfc.section.8.1.2.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.
     2965      </p>
     2966      <p id="rfc.section.8.1.2.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,
     2967         then the original URI's fragment identifier is added to the final value.
     2968      </p>
     2969      <div id="rfc.figure.u.52"></div>
     2970      <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
     2971</pre>  <p>would result in a final value of "http://www.example.org/pub/WWW/People.html#tim"</p>
     2972      <div id="rfc.figure.u.53"></div>
     2973      <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
     2974</pre>  <p>would result in a final value of "http://www.example.net/index.html#larry", preserving the original fragment identifier.</p>
     2975      <div class="note" id="rfc.section.8.1.2.p.7">
     2976         <p> <b>Note:</b> Some recipients attempt to recover from Location fields that are not valid URI references. This specification does not mandate
     2977            or define such processing, but does allow it.
    31102978         </p>
    31112979      </div>
    3112       <h2 id="rfc.section.8.6"><a href="#rfc.section.8.6">8.6</a>&nbsp;<a id="language.tags" href="#language.tags">Language Tags</a></h2>
    3113       <p id="rfc.section.8.6.p.1">A language tag, as defined in <a href="#RFC5646" id="rfc.xref.RFC5646.1"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, identifies a natural language spoken, written, or otherwise conveyed by human beings for communication of information to
    3114          other human beings. Computer languages are explicitly excluded. HTTP uses language tags within the <a href="#header.accept-language" class="smpl">Accept-Language</a> and <a href="#header.content-language" class="smpl">Content-Language</a> fields.
    3115       </p>
    3116       <p id="rfc.section.8.6.p.2">In summary, a language tag is composed of one or more parts: A primary language subtag followed by a possibly empty series
    3117          of subtags:
    3118       </p>
    3119       <div id="rfc.figure.u.60"></div><pre class="inline"><span id="rfc.iref.g.61"></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;
    3120 </pre><p id="rfc.section.8.6.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered
    3121          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;).
    3122       </p>
    3123       <div id="rfc.figure.u.61"></div>
    3124       <p>Example tags include:</p>  <pre class="text">  en, en-US, es-419, az-Arab, x-pig-latin, man-Nkoo-GN
    3125 </pre> <p id="rfc.section.8.6.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information.
    3126       </p>
     2980      <p id="rfc.section.8.1.2.p.8">There are circumstances in which a fragment identifier in a Location URI would not be appropriate. For instance, when it appears
     2981         in a <a href="#status.201" class="smpl">201
     2982            (Created)</a> response, where the Location header field specifies the URI for the entire created resource.
     2983      </p>
     2984      <div class="note" id="rfc.section.8.1.2.p.9">
     2985         <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;3.1.4.2</a>) differs from Location in that the Content-Location identifies the most specific resource corresponding to the enclosed representation.
     2986            It is therefore possible for a response to contain header fields for both Location and Content-Location.
     2987         </p>
     2988      </div>
     2989      <div id="rfc.iref.r.3"></div>
     2990      <h3 id="rfc.section.8.1.3"><a href="#rfc.section.8.1.3">8.1.3</a>&nbsp;<a id="header.retry-after" href="#header.retry-after">Retry-After</a></h3>
     2991      <p id="rfc.section.8.1.3.p.1">The header "Retry-After" field can be used with a <a href="#status.503" class="smpl">503 (Service
     2992            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.
     2993      </p>
     2994      <p id="rfc.section.8.1.3.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>
     2995      <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>
     2996</pre><div id="rule.delta-seconds">
     2997         <p id="rfc.section.8.1.3.p.4">  Time spans are non-negative decimal integers, representing time in seconds.</p>
     2998      </div>
     2999      <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>
     3000</pre><p id="rfc.section.8.1.3.p.6">Two examples of its use are</p>
     3001      <div id="rfc.figure.u.56"></div><pre class="text">  Retry-After: Fri, 31 Dec 1999 23:59:59 GMT
     3002  Retry-After: 120
     3003</pre><p id="rfc.section.8.1.3.p.8">In the latter example, the delay is 2 minutes.</p>
     3004      <h2 id="rfc.section.8.2"><a href="#rfc.section.8.2">8.2</a>&nbsp;<a id="selected.representation" href="#selected.representation">Selected Representation Header Fields</a></h2>
     3005      <p id="rfc.section.8.2.p.1"><span id="rfc.iref.s.7"></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
     3006         the same request had used the method GET and excluded any conditional request header fields.
     3007      </p>
     3008      <p id="rfc.section.8.2.p.2">Additional header fields define metadata about the selected representation, which might differ from the representation included
     3009         in the message for responses to some state-changing methods. The following header fields are defined as selected representation
     3010         metadata:
     3011      </p>
     3012      <div id="rfc.table.u.11">
     3013         <table class="tt full left" cellpadding="3" cellspacing="0">
     3014            <thead>
     3015               <tr>
     3016                  <th>Header Field Name</th>
     3017                  <th>Defined in...</th>
     3018               </tr>
     3019            </thead>
     3020            <tbody>
     3021               <tr>
     3022                  <td class="left">ETag</td>
     3023                  <td class="left"><a href="p4-conditional.html#header.etag" title="ETag">Section 2.3</a> of <a href="#Part4" id="rfc.xref.Part4.12"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a></td>
     3024               </tr>
     3025               <tr>
     3026                  <td class="left">Last-Modified</td>
     3027                  <td class="left"><a href="p4-conditional.html#header.last-modified" title="Last-Modified">Section 2.2</a> of <a href="#Part4" id="rfc.xref.Part4.13"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[Part4]</cite></a></td>
     3028               </tr>
     3029               <tr>
     3030                  <td class="left">Vary</td>
     3031                  <td class="left"><a href="#header.vary" id="rfc.xref.header.vary.2" title="Vary">Section&nbsp;8.2.1</a></td>
     3032               </tr>
     3033            </tbody>
     3034         </table>
     3035      </div>
     3036      <div id="rfc.iref.v.1"></div>
     3037      <h3 id="rfc.section.8.2.1"><a href="#rfc.section.8.2.1">8.2.1</a>&nbsp;<a id="header.vary" href="#header.vary">Vary</a></h3>
     3038      <p id="rfc.section.8.2.1.p.1">The "Vary" header field conveys the set of header fields that were used to select the representation.</p>
     3039      <p id="rfc.section.8.2.1.p.2">Caches use this information as part of determining whether a stored response can be used to satisfy a given request (<a href="p6-cache.html#caching.negotiated.responses" title="Using Negotiated Responses">Section 4.3</a> of <a href="#Part6" id="rfc.xref.Part6.16"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>).
     3040      </p>
     3041      <p id="rfc.section.8.2.1.p.3">In uncacheable or stale responses, the Vary field value advises the user agent about the criteria that were used to select
     3042         the representation.
     3043      </p>
     3044      <div id="rfc.figure.u.57"></div><pre class="inline"><span id="rfc.iref.g.59"></span>  <a href="#header.vary" class="smpl">Vary</a> = "*" / 1#<a href="#imported.abnf" class="smpl">field-name</a>
     3045</pre><p id="rfc.section.8.2.1.p.5">The set of header fields named by the Vary field value is known as the selecting header fields.</p>
     3046      <p id="rfc.section.8.2.1.p.6">A server <em class="bcp14">SHOULD</em> include a Vary header field with any cacheable response that is subject to proactive negotiation. Doing so allows a cache
     3047         to properly interpret future requests on that resource and informs the user agent about the presence of negotiation on that
     3048         resource. A server <em class="bcp14">MAY</em> include a Vary header field with a non-cacheable response that is subject to proactive negotiation, since this might provide
     3049         the user agent with useful information about the dimensions over which the response varies at the time of the response.
     3050      </p>
     3051      <p id="rfc.section.8.2.1.p.7">A Vary field value of "*" signals that unspecified parameters not limited to the header fields (e.g., the network address
     3052         of the client), play a role in the selection of the response representation; therefore, a cache cannot determine whether this
     3053         response is appropriate. A proxy <em class="bcp14">MUST NOT</em> generate the "*" value.
     3054      </p>
     3055      <p id="rfc.section.8.2.1.p.8">The field-names given are not limited to the set of standard header fields defined by this specification. Field names are
     3056         case-insensitive.
     3057      </p>
     3058      <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>
     3059      <p id="rfc.section.8.3.p.1">Authentication challenges indicate what mechanisms are available for the client to provide authentication credentials in future
     3060         requests.
     3061      </p>
     3062      <div id="rfc.table.u.12">
     3063         <table class="tt full left" cellpadding="3" cellspacing="0">
     3064            <thead>
     3065               <tr>
     3066                  <th>Header Field Name</th>
     3067                  <th>Defined in...</th>
     3068               </tr>
     3069            </thead>
     3070            <tbody>
     3071               <tr>
     3072                  <td class="left">WWW-Authenticate</td>
     3073                  <td class="left"><a href="p7-auth.html#header.www-authenticate" title="WWW-Authenticate">Section 4.4</a> of <a href="#Part7" id="rfc.xref.Part7.6"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Authentication">[Part7]</cite></a></td>
     3074               </tr>
     3075               <tr>
     3076                  <td class="left">Proxy-Authenticate</td>
     3077                  <td class="left"><a href="p7-auth.html#header.proxy-authenticate" title="Proxy-Authenticate">Section 4.2</a> of <a href="#Part7" id="rfc.xref.Part7.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Authentication">[Part7]</cite></a></td>
     3078               </tr>
     3079            </tbody>
     3080         </table>
     3081      </div>
     3082      <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>
     3083      <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>
     3084      <div id="rfc.table.u.13">
     3085         <table class="tt full left" cellpadding="3" cellspacing="0">
     3086            <thead>
     3087               <tr>
     3088                  <th>Header Field Name</th>
     3089                  <th>Defined in...</th>
     3090               </tr>
     3091            </thead>
     3092            <tbody>
     3093               <tr>
     3094                  <td class="left">Accept-Ranges</td>
     3095                  <td class="left"><a href="p5-range.html#header.accept-ranges" title="Accept-Ranges">Section 5.1</a> of <a href="#Part5" id="rfc.xref.Part5.10"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Range Requests">[Part5]</cite></a></td>
     3096               </tr>
     3097               <tr>
     3098                  <td class="left">Allow</td>
     3099                  <td class="left"><a href="#header.allow" id="rfc.xref.header.allow.2" title="Allow">Section&nbsp;8.4.1</a></td>
     3100               </tr>
     3101               <tr>
     3102                  <td class="left">Server</td>
     3103                  <td class="left"><a href="#header.server" id="rfc.xref.header.server.1" title="Server">Section&nbsp;8.4.2</a></td>
     3104               </tr>
     3105            </tbody>
     3106         </table>
     3107      </div>
     3108      <div id="rfc.iref.a.5"></div>
     3109      <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>
     3110      <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
     3111         is strictly to inform the recipient of valid request methods associated with the resource.
     3112      </p>
     3113      <div id="rfc.figure.u.58"></div><pre class="inline"><span id="rfc.iref.g.60"></span>  <a href="#header.allow" class="smpl">Allow</a> = #<a href="#method.overview" class="smpl">method</a>
     3114</pre><p id="rfc.section.8.4.1.p.3">Example of use:</p>
     3115      <div id="rfc.figure.u.59"></div><pre class="text">  Allow: GET, HEAD, PUT
     3116</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>
     3117      <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
     3118         to the generic message handling rules.
     3119      </p>
     3120      <div id="rfc.iref.s.8"></div>
     3121      <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>
     3122      <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>
     3123      <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;4</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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) identifying the server and any significant subproducts. The product tokens are listed in order of their significance for
     3124         identifying the application.
     3125      </p>
     3126      <div id="rfc.figure.u.60"></div><pre class="inline"><span id="rfc.iref.g.61"></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> ) )
     3127</pre><p id="rfc.section.8.4.2.p.4">Example:</p>
     3128      <div id="rfc.figure.u.61"></div><pre class="text">  Server: CERN/3.0 libwww/2.17
     3129</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="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>).
     3130      </p>
     3131      <div class="note" id="rfc.section.8.4.2.p.7">
     3132         <p> <b>Note:</b> Revealing the specific software version of the server might allow the server machine to become more vulnerable to attacks
     3133            against software that is known to contain security holes. Server implementers are encouraged to make this field a configurable
     3134            option.
     3135         </p>
     3136      </div>
    31273137      <h1 id="rfc.section.9"><a href="#rfc.section.9">9.</a>&nbsp;<a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>
    31283138      <h2 id="rfc.section.9.1"><a href="#rfc.section.9.1">9.1</a>&nbsp;<a id="method.registry" href="#method.registry">Method Registry</a></h2>
    3129       <p id="rfc.section.9.1.p.1">The HTTP Method Registry defines the name space for the request method token (<a href="#methods" title="Request Methods">Section&nbsp;4</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;.
     3139      <p id="rfc.section.9.1.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;.
    31303140      </p>
    31313141      <h3 id="rfc.section.9.1.1"><a href="#rfc.section.9.1.1">9.1.1</a>&nbsp;<a id="method.procedure" href="#method.procedure">Procedure</a></h3>
    … …  
    31333143      </p>
    31343144      <ul>
    3135          <li>Method Name (see <a href="#methods" title="Request Methods">Section&nbsp;4</a>)
    3136          </li>
    3137          <li>Safe ("yes" or "no", see <a href="#safe.methods" title="Safe Methods">Section&nbsp;4.2.1</a>)
    3138          </li>
    3139          <li>Idempotent ("yes" or "no", see <a href="#idempotent.methods" title="Idempotent Methods">Section&nbsp;4.2.2</a>)
     3145         <li>Method Name (see <a href="#methods" title="Request Methods">Section&nbsp;5</a>)
     3146         </li>
     3147         <li>Safe ("yes" or "no", see <a href="#safe.methods" title="Safe Methods">Section&nbsp;5.2.1</a>)
     3148         </li>
     3149         <li>Idempotent ("yes" or "no", see <a href="#idempotent.methods" title="Idempotent Methods">Section&nbsp;5.2.2</a>)
    31403150         </li>
    31413151         <li>Pointer to specification text</li>
    … …  
    31533163         value of "0".
    31543164      </p>
    3155       <p id="rfc.section.9.1.2.p.3">New method definitions need to indicate whether they are safe (<a href="#safe.methods" title="Safe Methods">Section&nbsp;4.2.1</a>), idempotent (<a href="#idempotent.methods" title="Idempotent Methods">Section&nbsp;4.2.2</a>), cacheable (<a href="#cacheable.methods" title="Cacheable Methods">Section&nbsp;4.2.3</a>), and what semantics are to be associated with the payload body if any is present in the request. If a method is cacheable,
     3165      <p id="rfc.section.9.1.2.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 payload body if any is present in the request. If a method is cacheable,
    31563166         the method definition ought to describe how, and under what conditions, a cache can store a response and use it to satisfy
    31573167         a subsequent request.
    … …  
    31753185                  <td class="left">no</td>
    31763186                  <td class="left">no</td>
    3177                   <td class="left"> <a href="#CONNECT" id="rfc.xref.CONNECT.2" title="CONNECT">Section&nbsp;4.3.6</a>
     3187                  <td class="left"> <a href="#CONNECT" id="rfc.xref.CONNECT.2" title="CONNECT">Section&nbsp;5.3.6</a>
    31783188                  </td>
    31793189               </tr>
    … …  
    31823192                  <td class="left">no</td>
    31833193                  <td class="left">yes</td>
    3184                   <td class="left"> <a href="#DELETE" id="rfc.xref.DELETE.2" title="DELETE">Section&nbsp;4.3.5</a>
     3194                  <td class="left"> <a href="#DELETE" id="rfc.xref.DELETE.2" title="DELETE">Section&nbsp;5.3.5</a>
    31853195                  </td>
    31863196               </tr>
    … …  
    31893199                  <td class="left">yes</td>
    31903200                  <td class="left">yes</td>
    3191                   <td class="left"> <a href="#GET" id="rfc.xref.GET.3" title="GET">Section&nbsp;4.3.1</a>
     3201                  <td class="left"> <a href="#GET" id="rfc.xref.GET.3" title="GET">Section&nbsp;5.3.1</a>
    31923202                  </td>
    31933203               </tr>
    … …  
    31963206                  <td class="left">yes</td>
    31973207                  <td class="left">yes</td>
    3198                   <td class="left"> <a href="#HEAD" id="rfc.xref.HEAD.2" title="HEAD">Section&nbsp;4.3.2</a>
     3208                  <td class="left"> <a href="#HEAD" id="rfc.xref.HEAD.2" title="HEAD">Section&nbsp;5.3.2</a>
    31993209                  </td>
    32003210               </tr>
    … …  
    32033213                  <td class="left">yes</td>
    32043214                  <td class="left">yes</td>
    3205                   <td class="left"> <a href="#OPTIONS" id="rfc.xref.OPTIONS.3" title="OPTIONS">Section&nbsp;4.3.7</a>
     3215                  <td class="left"> <a href="#OPTIONS" id="rfc.xref.OPTIONS.3" title="OPTIONS">Section&nbsp;5.3.7</a>
    32063216                  </td>
    32073217               </tr>
    … …  
    32103220                  <td class="left">no</td>
    32113221                  <td class="left">no</td>
    3212                   <td class="left"> <a href="#POST" id="rfc.xref.POST.3" title="POST">Section&nbsp;4.3.3</a>
     3222                  <td class="left"> <a href="#POST" id="rfc.xref.POST.3" title="POST">Section&nbsp;5.3.3</a>
    32133223                  </td>
    32143224               </tr>
    … …  
    32173227                  <td class="left">no</td>
    32183228                  <td class="left">yes</td>
    3219                   <td class="left"> <a href="#PUT" id="rfc.xref.PUT.3" title="PUT">Section&nbsp;4.3.4</a>
     3229                  <td class="left"> <a href="#PUT" id="rfc.xref.PUT.3" title="PUT">Section&nbsp;5.3.4</a>
    32203230                  </td>
    32213231               </tr>
    … …  
    32243234                  <td class="left">yes</td>
    32253235                  <td class="left">yes</td>
    3226                   <td class="left"> <a href="#TRACE" id="rfc.xref.TRACE.3" title="TRACE">Section&nbsp;4.3.8</a>
     3236                  <td class="left"> <a href="#TRACE" id="rfc.xref.TRACE.3" title="TRACE">Section&nbsp;5.3.8</a>
    32273237                  </td>
    32283238               </tr>
    … …  
    32313241      </div>
    32323242      <h2 id="rfc.section.9.2"><a href="#rfc.section.9.2">9.2</a>&nbsp;<a id="status.code.registry" href="#status.code.registry">Status Code Registry</a></h2>
    3233       <p id="rfc.section.9.2.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;6</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;.
     3243      <p id="rfc.section.9.2.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;.
    32343244      </p>
    32353245      <p id="rfc.section.9.2.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>.
    … …  
    32443254         isn't specific to a single application.
    32453255      </p>
    3246       <p id="rfc.section.9.2.2.p.2">New status codes are required to fall under one of the categories defined in <a href="#status.codes" title="Response Status Codes">Section&nbsp;6</a>. To allow existing parsers to properly handle them, new status codes cannot disallow a payload, although they can mandate
     3256      <p id="rfc.section.9.2.2.p.2">New 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 payload, although they can mandate
    32473257         a zero-length payload body.
    32483258      </p>
    … …  
    32503260         code (e.g., combinations of request header fields and/or method(s)) along with any dependencies on response header fields
    32513261         (e.g., what fields are required and what fields can modify the semantics). A response that can transfer a payload ought to
    3252          specify expected cache behavior (e.g., cacheability and freshness criteria, as described in <a href="#Part6" id="rfc.xref.Part6.17"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) and whether the payload has any implied association with an identified resource (<a href="#identifying.payload" title="Identifying the Payload">Section&nbsp;3.3.2</a>).
     3262         specify expected cache behavior (e.g., cacheability and freshness criteria, as described in <a href="#Part6" id="rfc.xref.Part6.17"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[Part6]</cite></a>) and whether the payload has any implied association with an identified resource (<a href="#identifying.payload" title="Identifying the Payload">Section&nbsp;3.1.4.1</a>).
    32533263      </p>
    32543264      <h3 id="rfc.section.9.2.3"><a href="#rfc.section.9.2.3">9.2.3</a>&nbsp;<a id="status.code.registration" href="#status.code.registration">Registrations</a></h3>
    … …  
    32683278                  <td class="left">100</td>
    32693279                  <td class="left">Continue</td>
    3270                   <td class="left"> <a href="#status.100" id="rfc.xref.status.100.4" title="100 Continue">Section&nbsp;6.2.1</a>
     3280                  <td class="left"> <a href="#status.100" id="rfc.xref.status.100.4" title="100 Continue">Section&nbsp;7.2.1</a>
    32713281                  </td>
    32723282               </tr>
    … …  
    32743284                  <td class="left">101</td>
    32753285                  <td class="left">Switching Protocols</td>
    3276                   <td class="left"> <a href="#status.101" id="rfc.xref.status.101.2" title="101 Switching Protocols">Section&nbsp;6.2.2</a>
     3286                  <td class="left"> <a href="#status.101" id="rfc.xref.status.101.2" title="101 Switching Protocols">Section&nbsp;7.2.2</a>
    32773287                  </td>
    32783288               </tr>
    … …  
    32803290                  <td class="left">200</td>
    32813291                  <td class="left">OK</td>
    3282                   <td class="left"> <a href="#status.200" id="rfc.xref.status.200.2" title="200 OK">Section&nbsp;6.3.1</a>
     3292                  <td class="left"> <a href="#status.200" id="rfc.xref.status.200.2" title="200 OK">Section&nbsp;7.3.1</a>
    32833293                  </td>
    32843294               </tr>
    … …  
    32863296                  <td class="left">201</td>
    32873297                  <td class="left">Created</td>
    3288                   <td class="left"> <a href="#status.201" id="rfc.xref.status.201.2" title="201 Created">Section&nbsp;6.3.2</a>
     3298                  <td class="left"> <a href="#status.201" id="rfc.xref.status.201.2" title="201 Created">Section&nbsp;7.3.2</a>
    32893299                  </td>
    32903300               </tr>
    … …  
    32923302                  <td class="left">202</td>
    32933303                  <td class="left">Accepted</td>
    3294                   <td class="left"> <a href="#status.202" id="rfc.xref.status.202.2" title="202 Accepted">Section&nbsp;6.3.3</a>
     3304                  <td class="left"> <a href="#status.202" id="rfc.xref.status.202.2" title="202 Accepted">Section&nbsp;7.3.3</a>
    32953305                  </td>
    32963306               </tr>
    … …  
    32983308                  <td class="left">203</td>
    32993309                  <td class="left">Non-Authoritative Information</td>
    3300                   <td class="left"> <a href="#status.203" id="rfc.xref.status.203.2" title="203 Non-Authoritative Information">Section&nbsp;6.3.4</a>
     3310                  <td class="left"> <a href="#status.203" id="rfc.xref.status.203.2" title="203 Non-Authoritative Information">Section&nbsp;7.3.4</a>
    33013311                  </td>
    33023312               </tr>
    … …  
    33043314                  <td class="left">204</td>
    33053315                  <td class="left">No Content</td>
    3306                   <td class="left"> <a href="#status.204" id="rfc.xref.status.204.2" title="204 No Content">Section&nbsp;6.3.5</a>
     3316                  <td class="left"> <a href="#status.204" id="rfc.xref.status.204.2" title="204 No Content">Section&nbsp;7.3.5</a>
    33073317                  </td>
    33083318               </tr>
    … …  
    33103320                  <td class="left">205</td>
    33113321                  <td class="left">Reset Content</td>
    3312                   <td class="left"> <a href="#status.205" id="rfc.xref.status.205.2" title="205 Reset Content">Section&nbsp;6.3.6</a>
     3322                  <td class="left"> <a href="#status.205" id="rfc.xref.status.205.2" title="205 Reset Content">Section&nbsp;7.3.6</a>
    33133323                  </td>
    33143324               </tr>
    … …  
    33163326                  <td class="left">300</td>
    33173327                  <td class="left">Multiple Choices</td>
    3318                   <td class="left"> <a href="#status.300" id="rfc.xref.status.300.2" title="300 Multiple Choices">Section&nbsp;6.4.1</a>
     3328                  <td class="left"> <a href="#status.300" id="rfc.xref.status.300.2" title="300 Multiple Choices">Section&nbsp;7.4.1</a>
    33193329                  </td>
    33203330               </tr>
    … …  
    33223332                  <td class="left">301</td>
    33233333                  <td class="left">Moved Permanently</td>
    3324                   <td class="left"> <a href="#status.301" id="rfc.xref.status.301.2" title="301 Moved Permanently">Section&nbsp;6.4.2</a>
     3334                  <td class="left"> <a href="#status.301" id="rfc.xref.status.301.2" title="301 Moved Permanently">Section&nbsp;7.4.2</a>
    33253335                  </td>
    33263336               </tr>
    … …  
    33283338                  <td class="left">302</td>
    33293339                  <td class="left">Found</td>
    3330                   <td class="left"> <a href="#status.302" id="rfc.xref.status.302.2" title="302 Found">Section&nbsp;6.4.3</a>
     3340                  <td class="left"> <a href="#status.302" id="rfc.xref.status.302.2" title="302 Found">Section&nbsp;7.4.3</a>
    33313341                  </td>
    33323342               </tr>
    … …  
    33343344                  <td class="left">303</td>
    33353345                  <td class="left">See Other</td>
    3336                   <td class="left"> <a href="#status.303" id="rfc.xref.status.303.2" title="303 See Other">Section&nbsp;6.4.4</a>
     3346                  <td class="left"> <a href="#status.303" id="rfc.xref.status.303.2" title="303 See Other">Section&nbsp;7.4.4</a>
    33373347                  </td>
    33383348               </tr>
    … …  
    33403350                  <td class="left">305</td>
    33413351                  <td class="left">Use Proxy</td>
    3342                   <td class="left"> <a href="#status.305" id="rfc.xref.status.305.2" title="305 Use Proxy">Section&nbsp;6.4.5</a>
     3352                  <td class="left"> <a href="#status.305" id="rfc.xref.status.305.2" title="305 Use Proxy">Section&nbsp;7.4.5</a>
    33433353                  </td>
    33443354               </tr>
    … …  
    33463356                  <td class="left">306</td>
    33473357                  <td class="left">(Unused)</td>
    3348                   <td class="left"> <a href="#status.306" id="rfc.xref.status.306.1" title="306 (Unused)">Section&nbsp;6.4.6</a>
     3358                  <td class="left"> <a href="#status.306" id="rfc.xref.status.306.1" title="306 (Unused)">Section&nbsp;7.4.6</a>
    33493359                  </td>
    33503360               </tr>
    … …  
    33523362                  <td class="left">307</td>
    33533363                  <td class="left">Temporary Redirect</td>
    3354                   <td class="left"> <a href="#status.307" id="rfc.xref.status.307.2" title="307 Temporary Redirect">Section&nbsp;6.4.7</a>
     3364                  <td class="left"> <a href="#status.307" id="rfc.xref.status.307.2" title="307 Temporary Redirect">Section&nbsp;7.4.7</a>
    33553365                  </td>
    33563366               </tr>
    … …  
    33583368                  <td class="left">400</td>
    33593369                  <td class="left">Bad Request</td>
    3360                   <td class="left"> <a href="#status.400" id="rfc.xref.status.400.2" title="400 Bad Request">Section&nbsp;6.5.1</a>
     3370                  <td class="left"> <a href="#status.400" id="rfc.xref.status.400.2" title="400 Bad Request">Section&nbsp;7.5.1</a>
    33613371                  </td>
    33623372               </tr>
    … …  
    33643374                  <td class="left">402</td>
    33653375                  <td class="left">Payment Required</td>
    3366                   <td class="left"> <a href="#status.402" id="rfc.xref.status.402.2" title="402 Payment Required">Section&nbsp;6.5.2</a>
     3376                  <td class="left"> <a href="#status.402" id="rfc.xref.status.402.2" title="402 Payment Required">Section&nbsp;7.5.2</a>
    33673377                  </td>
    33683378               </tr>
    … …  
    33703380                  <td class="left">403</td>
    33713381                  <td class="left">Forbidden</td>
    3372                   <td class="left"> <a href="#status.403" id="rfc.xref.status.403.2" title="403 Forbidden">Section&nbsp;6.5.3</a>
     3382                  <td class="left"> <a href="#status.403" id="rfc.xref.status.403.2" title="403 Forbidden">Section&nbsp;7.5.3</a>
    33733383                  </td>
    33743384               </tr>
    … …  
    33763386                  <td class="left">404</td>
    33773387                  <td class="left">Not Found</td>
    3378                   <td class="left"> <a href="#status.404" id="rfc.xref.status.404.2" title="404 Not Found">Section&nbsp;6.5.4</a>
     3388                  <td class="left"> <a href="#status.404" id="rfc.xref.status.404.2" title="404 Not Found">Section&nbsp;7.5.4</a>
    33793389                  </td>
    33803390               </tr>
    … …  
    33823392                  <td class="left">405</td>
    33833393                  <td class="left">Method Not Allowed</td>
    3384                   <td class="left"> <a href="#status.405" id="rfc.xref.status.405.2" title="405 Method Not Allowed">Section&nbsp;6.5.5</a>
     3394                  <td class="left"> <a href="#status.405" id="rfc.xref.status.405.2" title="405 Method Not Allowed">Section&nbsp;7.5.5</a>
    33853395                  </td>
    33863396               </tr>
    … …  
    33883398                  <td class="left">406</td>
    33893399                  <td class="left">Not Acceptable</td>
    3390                   <td class="left"> <a href="#status.406" id="rfc.xref.status.406.2" title="406 Not Acceptable">Section&nbsp;6.5.6</a>
     3400                  <td class="left"> <a href="#status.406" id="rfc.xref.status.406.2" title="406 Not Acceptable">Section&nbsp;7.5.6</a>
    33913401                  </td>
    33923402               </tr>
    … …  
    33943404                  <td class="left">408</td>
    33953405                  <td class="left">Request Timeout</td>
    3396                   <td class="left"> <a href="#status.408" id="rfc.xref.status.408.2" title="408 Request Timeout">Section&nbsp;6.5.7</a>
     3406                  <td class="left"> <a href="#status.408" id="rfc.xref.status.408.2" title="408 Request Timeout">Section&nbsp;7.5.7</a>
    33973407                  </td>
    33983408               </tr>
    … …  
    34003410                  <td class="left">409</td>
    34013411                  <td class="left">Conflict</td>
    3402                   <td class="left"> <a href="#status.409" id="rfc.xref.status.409.2" title="409 Conflict">Section&nbsp;6.5.8</a>
     3412                  <td class="left"> <a href="#status.409" id="rfc.xref.status.409.2" title="409 Conflict">Section&nbsp;7.5.8</a>
    34033413                  </td>
    34043414               </tr>
    … …  
    34063416                  <td class="left">410</td>
    34073417                  <td class="left">Gone</td>
    3408                   <td class="left"> <a href="#status.410" id="rfc.xref.status.410.2" title="410 Gone">Section&nbsp;6.5.9</a>
     3418                  <td class="left"> <a href="#status.410" id="rfc.xref.status.410.2" title="410 Gone">Section&nbsp;7.5.9</a>
    34093419                  </td>
    34103420               </tr>
    … …  
    34123422                  <td class="left">411</td>
    34133423                  <td class="left">Length Required</td>
    3414                   <td class="left"> <a href="#status.411" id="rfc.xref.status.411.2" title="411 Length Required">Section&nbsp;6.5.10</a>
     3424                  <td class="left"> <a href="#status.411" id="rfc.xref.status.411.2" title="411 Length Required">Section&nbsp;7.5.10</a>
    34153425                  </td>
    34163426               </tr>
    … …  
    34183428                  <td class="left">413</td>
    34193429                  <td class="left">Request Representation Too Large</td>
    3420                   <td class="left"> <a href="#status.413" id="rfc.xref.status.413.2" title="413 Request Representation Too Large">Section&nbsp;6.5.11</a>
     3430                  <td class="left"> <a href="#status.413" id="rfc.xref.status.413.2" title="413 Request Representation Too Large">Section&nbsp;7.5.11</a>
    34213431                  </td>
    34223432               </tr>
    … …  
    34243434                  <td class="left">414</td>