Ignore:
Timestamp:
Jul 29, 2009, 2:21:28 AM (10 years ago)
Author:
fielding@…
Message:

Resolve #93: say MUST NOT be sent unless instead of MAY be sent if and only if

File:
1 edited

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  • draft-ietf-httpbis/latest/p1-messaging.html

    r649 r651  
    360360      <link rel="Chapter" title="1 Introduction" href="#rfc.section.1">
    361361      <link rel="Chapter" title="2 HTTP architecture" href="#rfc.section.2">
    362       <link rel="Chapter" title="3 HTTP Message" href="#rfc.section.3">
    363       <link rel="Chapter" title="4 Request" href="#rfc.section.4">
    364       <link rel="Chapter" title="5 Response" href="#rfc.section.5">
    365       <link rel="Chapter" title="6 Protocol Parameters" href="#rfc.section.6">
    366       <link rel="Chapter" title="7 Connections" href="#rfc.section.7">
    367       <link rel="Chapter" title="8 Header Field Definitions" href="#rfc.section.8">
    368       <link rel="Chapter" title="9 IANA Considerations" href="#rfc.section.9">
    369       <link rel="Chapter" title="10 Security Considerations" href="#rfc.section.10">
    370       <link rel="Chapter" title="11 Acknowledgments" href="#rfc.section.11">
    371       <link rel="Chapter" href="#rfc.section.12" title="12 References">
     362      <link rel="Chapter" title="3 Header Field Definitions" href="#rfc.section.3">
     363      <link rel="Chapter" title="4 IANA Considerations" href="#rfc.section.4">
     364      <link rel="Chapter" title="5 Security Considerations" href="#rfc.section.5">
     365      <link rel="Chapter" title="6 Acknowledgments" href="#rfc.section.6">
     366      <link rel="Chapter" href="#rfc.section.7" title="7 References">
    372367      <link rel="Appendix" title="A Tolerant Applications" href="#rfc.section.A">
    373368      <link rel="Appendix" title="B Compatibility with Previous Versions" href="#rfc.section.B">
     
    471466         <tr>
    472467            <td class="header left"></td>
    473             <td class="header right">July 28, 2009</td>
     468            <td class="header right">July 29, 2009</td>
    474469         </tr>
    475470      </table>
     
    538533                     <li class="tocline1">2.6.2&nbsp;&nbsp;&nbsp;<a href="#https.uri">https URI scheme</a></li>
    539534                     <li class="tocline1">2.6.3&nbsp;&nbsp;&nbsp;<a href="#uri.comparison">http and https URI Normalization and Comparison</a></li>
    540                      <li class="tocline1">2.6.4&nbsp;&nbsp;&nbsp;<a href="#scheme.aliases">Scheme aliases considered harmful</a></li>
    541535                  </ul>
    542536               </li>
    543                <li class="tocline1">2.7&nbsp;&nbsp;&nbsp;<a href="#http.proxy">Use of HTTP for proxy communication</a></li>
    544                <li class="tocline1">2.8&nbsp;&nbsp;&nbsp;<a href="#http.intercept">Interception of HTTP for access control</a></li>
    545                <li class="tocline1">2.9&nbsp;&nbsp;&nbsp;<a href="#http.others">Use of HTTP by other protocols</a></li>
    546                <li class="tocline1">2.10&nbsp;&nbsp;&nbsp;<a href="#http.media">Use of HTTP by media type specification</a></li>
    547             </ul>
    548          </li>
    549          <li class="tocline0">3.&nbsp;&nbsp;&nbsp;<a href="#http.message">HTTP Message</a><ul class="toc">
    550                <li class="tocline1">3.1&nbsp;&nbsp;&nbsp;<a href="#message.robustness">Message Parsing Robustness</a></li>
    551                <li class="tocline1">3.2&nbsp;&nbsp;&nbsp;<a href="#header.fields">Header Fields</a></li>
    552                <li class="tocline1">3.3&nbsp;&nbsp;&nbsp;<a href="#message.body">Message Body</a></li>
    553                <li class="tocline1">3.4&nbsp;&nbsp;&nbsp;<a href="#message.length">Message Length</a></li>
    554                <li class="tocline1">3.5&nbsp;&nbsp;&nbsp;<a href="#general.header.fields">General Header Fields</a></li>
    555             </ul>
    556          </li>
    557          <li class="tocline0">4.&nbsp;&nbsp;&nbsp;<a href="#request">Request</a><ul class="toc">
    558                <li class="tocline1">4.1&nbsp;&nbsp;&nbsp;<a href="#request-line">Request-Line</a><ul class="toc">
    559                      <li class="tocline1">4.1.1&nbsp;&nbsp;&nbsp;<a href="#method">Method</a></li>
    560                      <li class="tocline1">4.1.2&nbsp;&nbsp;&nbsp;<a href="#request-target">request-target</a></li>
     537               <li class="tocline1">2.7&nbsp;&nbsp;&nbsp;<a href="#http.message">HTTP Message</a><ul class="toc">
     538                     <li class="tocline1">2.7.1&nbsp;&nbsp;&nbsp;<a href="#message.robustness">Message Parsing Robustness</a></li>
     539                     <li class="tocline1">2.7.2&nbsp;&nbsp;&nbsp;<a href="#header.fields">Header Fields</a></li>
     540                     <li class="tocline1">2.7.3&nbsp;&nbsp;&nbsp;<a href="#message.body">Message Body</a></li>
     541                     <li class="tocline1">2.7.4&nbsp;&nbsp;&nbsp;<a href="#message.length">Message Length</a></li>
     542                     <li class="tocline1">2.7.5&nbsp;&nbsp;&nbsp;<a href="#general.header.fields">General Header Fields</a></li>
    561543                  </ul>
    562544               </li>
    563                <li class="tocline1">4.2&nbsp;&nbsp;&nbsp;<a href="#the.resource.identified.by.a.request">The Resource Identified by a Request</a></li>
    564             </ul>
    565          </li>
    566          <li class="tocline0">5.&nbsp;&nbsp;&nbsp;<a href="#response">Response</a><ul class="toc">
    567                <li class="tocline1">5.1&nbsp;&nbsp;&nbsp;<a href="#status-line">Status-Line</a><ul class="toc">
    568                      <li class="tocline1">5.1.1&nbsp;&nbsp;&nbsp;<a href="#status.code.and.reason.phrase">Status Code and Reason Phrase</a></li>
     545               <li class="tocline1">2.8&nbsp;&nbsp;&nbsp;<a href="#request">Request</a><ul class="toc">
     546                     <li class="tocline1">2.8.1&nbsp;&nbsp;&nbsp;<a href="#request-line">Request-Line</a><ul class="toc">
     547                           <li class="tocline1">2.8.1.1&nbsp;&nbsp;&nbsp;<a href="#method">Method</a></li>
     548                           <li class="tocline1">2.8.1.2&nbsp;&nbsp;&nbsp;<a href="#request-target">request-target</a></li>
     549                        </ul>
     550                     </li>
     551                     <li class="tocline1">2.8.2&nbsp;&nbsp;&nbsp;<a href="#the.resource.identified.by.a.request">The Resource Identified by a Request</a></li>
    569552                  </ul>
    570553               </li>
    571             </ul>
    572          </li>
    573          <li class="tocline0">6.&nbsp;&nbsp;&nbsp;<a href="#protocol.parameters">Protocol Parameters</a><ul class="toc">
    574                <li class="tocline1">6.1&nbsp;&nbsp;&nbsp;<a href="#date.time.formats.full.date">Date/Time Formats: Full Date</a></li>
    575                <li class="tocline1">6.2&nbsp;&nbsp;&nbsp;<a href="#transfer.codings">Transfer Codings</a><ul class="toc">
    576                      <li class="tocline1">6.2.1&nbsp;&nbsp;&nbsp;<a href="#chunked.transfer.encoding">Chunked Transfer Coding</a></li>
     554               <li class="tocline1">2.9&nbsp;&nbsp;&nbsp;<a href="#response">Response</a><ul class="toc">
     555                     <li class="tocline1">2.9.1&nbsp;&nbsp;&nbsp;<a href="#status-line">Status-Line</a><ul class="toc">
     556                           <li class="tocline1">2.9.1.1&nbsp;&nbsp;&nbsp;<a href="#status.code.and.reason.phrase">Status Code and Reason Phrase</a></li>
     557                        </ul>
     558                     </li>
    577559                  </ul>
    578560               </li>
    579                <li class="tocline1">6.3&nbsp;&nbsp;&nbsp;<a href="#product.tokens">Product Tokens</a></li>
    580                <li class="tocline1">6.4&nbsp;&nbsp;&nbsp;<a href="#quality.values">Quality Values</a></li>
    581             </ul>
    582          </li>
    583          <li class="tocline0">7.&nbsp;&nbsp;&nbsp;<a href="#connections">Connections</a><ul class="toc">
    584                <li class="tocline1">7.1&nbsp;&nbsp;&nbsp;<a href="#persistent.connections">Persistent Connections</a><ul class="toc">
    585                      <li class="tocline1">7.1.1&nbsp;&nbsp;&nbsp;<a href="#persistent.purpose">Purpose</a></li>
    586                      <li class="tocline1">7.1.2&nbsp;&nbsp;&nbsp;<a href="#persistent.overall">Overall Operation</a><ul class="toc">
    587                            <li class="tocline1">7.1.2.1&nbsp;&nbsp;&nbsp;<a href="#persistent.negotiation">Negotiation</a></li>
    588                            <li class="tocline1">7.1.2.2&nbsp;&nbsp;&nbsp;<a href="#pipelining">Pipelining</a></li>
     561               <li class="tocline1">2.10&nbsp;&nbsp;&nbsp;<a href="#protocol.parameters">Protocol Parameters</a><ul class="toc">
     562                     <li class="tocline1">2.10.1&nbsp;&nbsp;&nbsp;<a href="#date.time.formats.full.date">Date/Time Formats: Full Date</a></li>
     563                     <li class="tocline1">2.10.2&nbsp;&nbsp;&nbsp;<a href="#transfer.codings">Transfer Codings</a><ul class="toc">
     564                           <li class="tocline1">2.10.2.1&nbsp;&nbsp;&nbsp;<a href="#chunked.transfer.encoding">Chunked Transfer Coding</a></li>
    589565                        </ul>
    590566                     </li>
    591                      <li class="tocline1">7.1.3&nbsp;&nbsp;&nbsp;<a href="#persistent.proxy">Proxy Servers</a></li>
    592                      <li class="tocline1">7.1.4&nbsp;&nbsp;&nbsp;<a href="#persistent.practical">Practical Considerations</a></li>
     567                     <li class="tocline1">2.10.3&nbsp;&nbsp;&nbsp;<a href="#product.tokens">Product Tokens</a></li>
     568                     <li class="tocline1">2.10.4&nbsp;&nbsp;&nbsp;<a href="#quality.values">Quality Values</a></li>
    593569                  </ul>
    594570               </li>
    595                <li class="tocline1">7.2&nbsp;&nbsp;&nbsp;<a href="#message.transmission.requirements">Message Transmission Requirements</a><ul class="toc">
    596                      <li class="tocline1">7.2.1&nbsp;&nbsp;&nbsp;<a href="#persistent.flow">Persistent Connections and Flow Control</a></li>
    597                      <li class="tocline1">7.2.2&nbsp;&nbsp;&nbsp;<a href="#persistent.monitor">Monitoring Connections for Error Status Messages</a></li>
    598                      <li class="tocline1">7.2.3&nbsp;&nbsp;&nbsp;<a href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></li>
    599                      <li class="tocline1">7.2.4&nbsp;&nbsp;&nbsp;<a href="#connection.premature">Client Behavior if Server Prematurely Closes Connection</a></li>
     571               <li class="tocline1">2.11&nbsp;&nbsp;&nbsp;<a href="#connections">Connections</a><ul class="toc">
     572                     <li class="tocline1">2.11.1&nbsp;&nbsp;&nbsp;<a href="#persistent.connections">Persistent Connections</a><ul class="toc">
     573                           <li class="tocline1">2.11.1.1&nbsp;&nbsp;&nbsp;<a href="#persistent.purpose">Purpose</a></li>
     574                           <li class="tocline1">2.11.1.2&nbsp;&nbsp;&nbsp;<a href="#persistent.overall">Overall Operation</a><ul class="toc">
     575                                 <li class="tocline1">2.11.1.2.1&nbsp;&nbsp;&nbsp;<a href="#persistent.negotiation">Negotiation</a></li>
     576                                 <li class="tocline1">2.11.1.2.2&nbsp;&nbsp;&nbsp;<a href="#pipelining">Pipelining</a></li>
     577                              </ul>
     578                           </li>
     579                           <li class="tocline1">2.11.1.3&nbsp;&nbsp;&nbsp;<a href="#persistent.proxy">Proxy Servers</a></li>
     580                           <li class="tocline1">2.11.1.4&nbsp;&nbsp;&nbsp;<a href="#persistent.practical">Practical Considerations</a></li>
     581                        </ul>
     582                     </li>
     583                     <li class="tocline1">2.11.2&nbsp;&nbsp;&nbsp;<a href="#message.transmission.requirements">Message Transmission Requirements</a><ul class="toc">
     584                           <li class="tocline1">2.11.2.1&nbsp;&nbsp;&nbsp;<a href="#persistent.flow">Persistent Connections and Flow Control</a></li>
     585                           <li class="tocline1">2.11.2.2&nbsp;&nbsp;&nbsp;<a href="#persistent.monitor">Monitoring Connections for Error Status Messages</a></li>
     586                           <li class="tocline1">2.11.2.3&nbsp;&nbsp;&nbsp;<a href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></li>
     587                           <li class="tocline1">2.11.2.4&nbsp;&nbsp;&nbsp;<a href="#connection.premature">Client Behavior if Server Prematurely Closes Connection</a></li>
     588                        </ul>
     589                     </li>
    600590                  </ul>
    601591               </li>
    602             </ul>
    603          </li>
    604          <li class="tocline0">8.&nbsp;&nbsp;&nbsp;<a href="#header.field.definitions">Header Field Definitions</a><ul class="toc">
    605                <li class="tocline1">8.1&nbsp;&nbsp;&nbsp;<a href="#header.connection">Connection</a></li>
    606                <li class="tocline1">8.2&nbsp;&nbsp;&nbsp;<a href="#header.content-length">Content-Length</a></li>
    607                <li class="tocline1">8.3&nbsp;&nbsp;&nbsp;<a href="#header.date">Date</a><ul class="toc">
    608                      <li class="tocline1">8.3.1&nbsp;&nbsp;&nbsp;<a href="#clockless.origin.server.operation">Clockless Origin Server Operation</a></li>
     592               <li class="tocline1">2.12&nbsp;&nbsp;&nbsp;<a href="#misc">Miscellaneous notes that may disappear</a><ul class="toc">
     593                     <li class="tocline1">2.12.1&nbsp;&nbsp;&nbsp;<a href="#scheme.aliases">Scheme aliases considered harmful</a></li>
    609594                  </ul>
    610595               </li>
    611                <li class="tocline1">8.4&nbsp;&nbsp;&nbsp;<a href="#header.host">Host</a></li>
    612                <li class="tocline1">8.5&nbsp;&nbsp;&nbsp;<a href="#header.te">TE</a></li>
    613                <li class="tocline1">8.6&nbsp;&nbsp;&nbsp;<a href="#header.trailer">Trailer</a></li>
    614                <li class="tocline1">8.7&nbsp;&nbsp;&nbsp;<a href="#header.transfer-encoding">Transfer-Encoding</a></li>
    615                <li class="tocline1">8.8&nbsp;&nbsp;&nbsp;<a href="#header.upgrade">Upgrade</a></li>
    616                <li class="tocline1">8.9&nbsp;&nbsp;&nbsp;<a href="#header.via">Via</a></li>
     596               <li class="tocline1">2.13&nbsp;&nbsp;&nbsp;<a href="#http.proxy">Use of HTTP for proxy communication</a></li>
     597               <li class="tocline1">2.14&nbsp;&nbsp;&nbsp;<a href="#http.intercept">Interception of HTTP for access control</a></li>
     598               <li class="tocline1">2.15&nbsp;&nbsp;&nbsp;<a href="#http.others">Use of HTTP by other protocols</a></li>
     599               <li class="tocline1">2.16&nbsp;&nbsp;&nbsp;<a href="#http.media">Use of HTTP by media type specification</a></li>
    617600            </ul>
    618601         </li>
    619          <li class="tocline0">9.&nbsp;&nbsp;&nbsp;<a href="#IANA.considerations">IANA Considerations</a><ul class="toc">
    620                <li class="tocline1">9.1&nbsp;&nbsp;&nbsp;<a href="#message.header.registration">Message Header Registration</a></li>
    621                <li class="tocline1">9.2&nbsp;&nbsp;&nbsp;<a href="#uri.scheme.registration">URI Scheme Registration</a></li>
    622                <li class="tocline1">9.3&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.http">Internet Media Type Registrations</a><ul class="toc">
    623                      <li class="tocline1">9.3.1&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.message.http">Internet Media Type message/http</a></li>
    624                      <li class="tocline1">9.3.2&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.application.http">Internet Media Type application/http</a></li>
     602         <li class="tocline0">3.&nbsp;&nbsp;&nbsp;<a href="#header.field.definitions">Header Field Definitions</a><ul class="toc">
     603               <li class="tocline1">3.1&nbsp;&nbsp;&nbsp;<a href="#header.connection">Connection</a></li>
     604               <li class="tocline1">3.2&nbsp;&nbsp;&nbsp;<a href="#header.content-length">Content-Length</a></li>
     605               <li class="tocline1">3.3&nbsp;&nbsp;&nbsp;<a href="#header.date">Date</a><ul class="toc">
     606                     <li class="tocline1">3.3.1&nbsp;&nbsp;&nbsp;<a href="#clockless.origin.server.operation">Clockless Origin Server Operation</a></li>
    625607                  </ul>
    626608               </li>
     609               <li class="tocline1">3.4&nbsp;&nbsp;&nbsp;<a href="#header.host">Host</a></li>
     610               <li class="tocline1">3.5&nbsp;&nbsp;&nbsp;<a href="#header.te">TE</a></li>
     611               <li class="tocline1">3.6&nbsp;&nbsp;&nbsp;<a href="#header.trailer">Trailer</a></li>
     612               <li class="tocline1">3.7&nbsp;&nbsp;&nbsp;<a href="#header.transfer-encoding">Transfer-Encoding</a></li>
     613               <li class="tocline1">3.8&nbsp;&nbsp;&nbsp;<a href="#header.upgrade">Upgrade</a></li>
     614               <li class="tocline1">3.9&nbsp;&nbsp;&nbsp;<a href="#header.via">Via</a></li>
    627615            </ul>
    628616         </li>
    629          <li class="tocline0">10.&nbsp;&nbsp;&nbsp;<a href="#security.considerations">Security Considerations</a><ul class="toc">
    630                <li class="tocline1">10.1&nbsp;&nbsp;&nbsp;<a href="#personal.information">Personal Information</a></li>
    631                <li class="tocline1">10.2&nbsp;&nbsp;&nbsp;<a href="#abuse.of.server.log.information">Abuse of Server Log Information</a></li>
    632                <li class="tocline1">10.3&nbsp;&nbsp;&nbsp;<a href="#attack.pathname">Attacks Based On File and Path Names</a></li>
    633                <li class="tocline1">10.4&nbsp;&nbsp;&nbsp;<a href="#dns.spoofing">DNS Spoofing</a></li>
    634                <li class="tocline1">10.5&nbsp;&nbsp;&nbsp;<a href="#attack.proxies">Proxies and Caching</a></li>
    635                <li class="tocline1">10.6&nbsp;&nbsp;&nbsp;<a href="#attack.DoS">Denial of Service Attacks on Proxies</a></li>
     617         <li class="tocline0">4.&nbsp;&nbsp;&nbsp;<a href="#IANA.considerations">IANA Considerations</a><ul class="toc">
     618               <li class="tocline1">4.1&nbsp;&nbsp;&nbsp;<a href="#message.header.registration">Message Header Registration</a></li>
     619               <li class="tocline1">4.2&nbsp;&nbsp;&nbsp;<a href="#uri.scheme.registration">URI Scheme Registration</a></li>
     620               <li class="tocline1">4.3&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.http">Internet Media Type Registrations</a><ul class="toc">
     621                     <li class="tocline1">4.3.1&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.message.http">Internet Media Type message/http</a></li>
     622                     <li class="tocline1">4.3.2&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.application.http">Internet Media Type application/http</a></li>
     623                  </ul>
     624               </li>
     625               <li class="tocline1">4.4&nbsp;&nbsp;&nbsp;<a href="#transfer.coding.registration">Transfer Coding Registry</a></li>
    636626            </ul>
    637627         </li>
    638          <li class="tocline0">11.&nbsp;&nbsp;&nbsp;<a href="#ack">Acknowledgments</a></li>
    639          <li class="tocline0">12.&nbsp;&nbsp;&nbsp;<a href="#rfc.references">References</a><ul class="toc">
    640                <li class="tocline1">12.1&nbsp;&nbsp;&nbsp;<a href="#rfc.references.1">Normative References</a></li>
    641                <li class="tocline1">12.2&nbsp;&nbsp;&nbsp;<a href="#rfc.references.2">Informative References</a></li>
     628         <li class="tocline0">5.&nbsp;&nbsp;&nbsp;<a href="#security.considerations">Security Considerations</a><ul class="toc">
     629               <li class="tocline1">5.1&nbsp;&nbsp;&nbsp;<a href="#personal.information">Personal Information</a></li>
     630               <li class="tocline1">5.2&nbsp;&nbsp;&nbsp;<a href="#abuse.of.server.log.information">Abuse of Server Log Information</a></li>
     631               <li class="tocline1">5.3&nbsp;&nbsp;&nbsp;<a href="#attack.pathname">Attacks Based On File and Path Names</a></li>
     632               <li class="tocline1">5.4&nbsp;&nbsp;&nbsp;<a href="#dns.spoofing">DNS Spoofing</a></li>
     633               <li class="tocline1">5.5&nbsp;&nbsp;&nbsp;<a href="#attack.proxies">Proxies and Caching</a></li>
     634               <li class="tocline1">5.6&nbsp;&nbsp;&nbsp;<a href="#attack.DoS">Denial of Service Attacks on Proxies</a></li>
     635            </ul>
     636         </li>
     637         <li class="tocline0">6.&nbsp;&nbsp;&nbsp;<a href="#ack">Acknowledgments</a></li>
     638         <li class="tocline0">7.&nbsp;&nbsp;&nbsp;<a href="#rfc.references">References</a><ul class="toc">
     639               <li class="tocline1">7.1&nbsp;&nbsp;&nbsp;<a href="#rfc.references.1">Normative References</a></li>
     640               <li class="tocline1">7.2&nbsp;&nbsp;&nbsp;<a href="#rfc.references.2">Informative References</a></li>
    642641            </ul>
    643642         </li>
     
    769768                 ; "bad" whitespace
    770769  <a href="#rule.whitespace" class="smpl">obs-fold</a>       = <a href="#core.rules" class="smpl">CRLF</a>
    771                  ; see <a href="#header.fields" title="Header Fields">Section&nbsp;3.2</a>
     770                 ; see <a href="#header.fields" title="Header Fields">Section&nbsp;2.7.2</a>
    772771</pre><div id="rule.token.separators">
    773          <p id="rfc.section.1.2.2.p.8">    Many HTTP/1.1 header field values consist of words separated by whitespace or special characters. These special characters <em class="bcp14">MUST</em> be in a quoted string to be used within a parameter value (as defined in <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;6.2</a>).
     772         <p id="rfc.section.1.2.2.p.8">    Many HTTP/1.1 header field values consist of words separated by whitespace or special characters. These special characters <em class="bcp14">MUST</em> be in a quoted string to be used within a parameter value (as defined in <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;2.10.2</a>).
    774773         </p>
    775774      </div>
     
    832831      <div id="rfc.iref.r.1"></div>
    833832      <div id="rfc.iref.r.2"></div>
    834       <p id="rfc.section.2.1.p.5">A client sends an HTTP request to the server in the form of a request message (<a href="#request" title="Request">Section&nbsp;4</a>), beginning with a method, URI, and protocol version, followed by MIME-like header fields containing request modifiers, client
    835          information, and payload metadata, an empty line, and finally the payload body (if any). The server response (<a href="#response" title="Response">Section&nbsp;5</a>) begins with a status line, including the protocol version, a success or error code, and textual reason phrase, followed
     833      <p id="rfc.section.2.1.p.5">A client sends an HTTP request to the server in the form of a request message (<a href="#request" title="Request">Section&nbsp;2.8</a>), beginning with a method, URI, and protocol version, followed by MIME-like header fields containing request modifiers, client
     834         information, and payload metadata, an empty line, and finally the payload body (if any). The server response (<a href="#response" title="Response">Section&nbsp;2.9</a>) begins with a status line, including the protocol version, a success or error code, and textual reason phrase, followed
    836835         by MIME-like header fields containing server information, resource metadata, payload metadata, an empty line, and finally
    837836         the payload body (if any).
     
    928927      </p>
    929928      <p id="rfc.section.2.4.p.3">In HTTP/1.0, most implementations used a new connection for each request/response exchange. In HTTP/1.1, a connection may
    930          be used for one or more request/response exchanges, although connections may be closed for a variety of reasons (see <a href="#persistent.connections" title="Persistent Connections">Section&nbsp;7.1</a>).
     929         be used for one or more request/response exchanges, although connections may be closed for a variety of reasons (see <a href="#persistent.connections" title="Persistent Connections">Section&nbsp;2.11.1</a>).
    931930      </p>
    932931      <h2 id="rfc.section.2.5"><a href="#rfc.section.2.5">2.5</a>&nbsp;<a id="http.version" href="#http.version">HTTP Version</a></h2>
     
    10071006      </p>
    10081007      <p id="rfc.section.2.6.1.p.5">When an "http" URI is used within a context that calls for access to the indicated resource, a client <em class="bcp14">MAY</em> attempt access by resolving the host to an IP address, establishing a TCP connection to that address on the indicated port,
    1009          and sending an HTTP request message to the server containing the URI's identifying data as described in <a href="#request" title="Request">Section&nbsp;4</a>. If the server responds to that request with a non-interim HTTP response message, as described in <a href="#response" title="Response">Section&nbsp;5</a>, then that response is considered an authoritative answer to the client's request.
     1008         and sending an HTTP request message to the server containing the URI's identifying data as described in <a href="#request" title="Request">Section&nbsp;2.8</a>. If the server responds to that request with a non-interim HTTP response message, as described in <a href="#response" title="Response">Section&nbsp;2.9</a>, then that response is considered an authoritative answer to the client's request.
    10101009      </p>
    10111010      <p id="rfc.section.2.6.1.p.6">Although HTTP is independent of the transport protocol, the "http" scheme is specific to TCP-based services because the name
     
    10451044   http://EXAMPLE.com:/%7esmith/home.html
    10461045</pre><p id="rfc.section.2.6.3.p.5"> <span class="comment" id="rfc.comment.1">[<a href="#rfc.comment.1" class="smpl">rfc.comment.1</a>: [[This paragraph does not belong here. --Roy]]]</span> If path-abempty is the empty string (i.e., there is no slash "/" path separator following the authority), then the "http"
    1047          URI <em class="bcp14">MUST</em> be given as "/" when used as a request-target (<a href="#request-target" title="request-target">Section&nbsp;4.1.2</a>). If a proxy receives a host name which is not a fully qualified domain name, it <em class="bcp14">MAY</em> add its domain to the host name it received. If a proxy receives a fully qualified domain name, the proxy <em class="bcp14">MUST NOT</em> change the host name.
    1048       </p>
    1049       <h3 id="rfc.section.2.6.4"><a href="#rfc.section.2.6.4">2.6.4</a>&nbsp;<a id="scheme.aliases" href="#scheme.aliases">Scheme aliases considered harmful</a></h3>
    1050       <p id="rfc.section.2.6.4.p.1"> <span class="comment" id="rfc.comment.2">[<a href="#rfc.comment.2" class="smpl">rfc.comment.2</a>: TBS: describe why aliases like webcal are harmful.]</span>
    1051       </p>
    1052       <h2 id="rfc.section.2.7"><a href="#rfc.section.2.7">2.7</a>&nbsp;<a id="http.proxy" href="#http.proxy">Use of HTTP for proxy communication</a></h2>
    1053       <p id="rfc.section.2.7.p.1"> <span class="comment" id="rfc.comment.3">[<a href="#rfc.comment.3" class="smpl">rfc.comment.3</a>: TBD: Configured to use HTTP to proxy HTTP or other protocols.]</span>
    1054       </p>
    1055       <h2 id="rfc.section.2.8"><a href="#rfc.section.2.8">2.8</a>&nbsp;<a id="http.intercept" href="#http.intercept">Interception of HTTP for access control</a></h2>
    1056       <p id="rfc.section.2.8.p.1"> <span class="comment" id="rfc.comment.4">[<a href="#rfc.comment.4" class="smpl">rfc.comment.4</a>: TBD: Interception of HTTP traffic for initiating access control.]</span>
    1057       </p>
    1058       <h2 id="rfc.section.2.9"><a href="#rfc.section.2.9">2.9</a>&nbsp;<a id="http.others" href="#http.others">Use of HTTP by other protocols</a></h2>
    1059       <p id="rfc.section.2.9.p.1"> <span class="comment" id="rfc.comment.5">[<a href="#rfc.comment.5" class="smpl">rfc.comment.5</a>: TBD: Profiles of HTTP defined by other protocol. Extensions of HTTP like WebDAV.]</span>
    1060       </p>
    1061       <h2 id="rfc.section.2.10"><a href="#rfc.section.2.10">2.10</a>&nbsp;<a id="http.media" href="#http.media">Use of HTTP by media type specification</a></h2>
    1062       <p id="rfc.section.2.10.p.1"> <span class="comment" id="rfc.comment.6">[<a href="#rfc.comment.6" class="smpl">rfc.comment.6</a>: TBD: Instructions on composing HTTP requests via hypertext formats.]</span>
    1063       </p>
    1064       <h1 id="rfc.section.3"><a href="#rfc.section.3">3.</a>&nbsp;<a id="http.message" href="#http.message">HTTP Message</a></h1>
     1046         URI <em class="bcp14">MUST</em> be given as "/" when used as a request-target (<a href="#request-target" title="request-target">Section&nbsp;2.8.1.2</a>). If a proxy receives a host name which is not a fully qualified domain name, it <em class="bcp14">MAY</em> add its domain to the host name it received. If a proxy receives a fully qualified domain name, the proxy <em class="bcp14">MUST NOT</em> change the host name.
     1047      </p>
     1048      <h2 id="rfc.section.2.7"><a href="#rfc.section.2.7">2.7</a>&nbsp;<a id="http.message" href="#http.message">HTTP Message</a></h2>
    10651049      <div id="rfc.iref.h.3"></div>
    10661050      <div id="rfc.iref.h.4"></div>
    10671051      <div id="rfc.iref.h.5"></div>
    1068       <p id="rfc.section.3.p.1">All HTTP/1.1 messages consist of a start-line followed by a sequence of characters in a format similar to the Internet Message
     1052      <p id="rfc.section.2.7.p.1">All HTTP/1.1 messages consist of a start-line followed by a sequence of characters in a format similar to the Internet Message
    10691053         Format <a href="#RFC5322" id="rfc.xref.RFC5322.2"><cite title="Internet Message Format">[RFC5322]</cite></a>: zero or more header fields (collectively referred to as the "headers" or the "header section"), an empty line indicating
    10701054         the end of the header section, and an optional message-body.
    10711055      </p>
    1072       <p id="rfc.section.3.p.2">An HTTP message can either be a request from client to server or a response from server to client. Syntactically, the two
     1056      <p id="rfc.section.2.7.p.2">An HTTP message can either be a request from client to server or a response from server to client. Syntactically, the two
    10731057         types of message differ only in the start-line, which is either a Request-Line (for requests) or a Status-Line (for responses),
    1074          and in the algorithm for determining the length of the message-body (<a href="#message.length" title="Message Length">Section&nbsp;3.4</a>). In theory, a client could receive requests and a server could receive responses, distinguishing them by their different
     1058         and in the algorithm for determining the length of the message-body (<a href="#message.length" title="Message Length">Section&nbsp;2.7.4</a>). In theory, a client could receive requests and a server could receive responses, distinguishing them by their different
    10751059         start-line formats, but in practice servers are implemented to only expect a request (a response is interpreted as an unknown
    10761060         or invalid request method) and clients are implemented to only expect a response.
     
    10811065                    [ <a href="#message.body" class="smpl">message-body</a> ]
    10821066  <a href="#http.message" class="smpl">start-line</a>      = <a href="#request-line" class="smpl">Request-Line</a> / <a href="#status-line" class="smpl">Status-Line</a>
    1083 </pre><p id="rfc.section.3.p.4">Whitespace (WSP) <em class="bcp14">MUST NOT</em> be sent between the start-line and the first header field. The presence of whitespace might be an attempt to trick a noncompliant
     1067</pre><p id="rfc.section.2.7.p.4">Whitespace (WSP) <em class="bcp14">MUST NOT</em> be sent between the start-line and the first header field. The presence of whitespace might be an attempt to trick a noncompliant
    10841068         implementation of HTTP into ignoring that field or processing the next line as a new request, either of which may result in
    10851069         security issues when implementations within the request chain interpret the same message differently. HTTP/1.1 servers <em class="bcp14">MUST</em> reject such a message with a 400 (Bad Request) response.
    10861070      </p>
    1087       <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a id="message.robustness" href="#message.robustness">Message Parsing Robustness</a></h2>
    1088       <p id="rfc.section.3.1.p.1">In the interest of robustness, servers <em class="bcp14">SHOULD</em> ignore at least one empty line received where a Request-Line is expected. In other words, if the server is reading the protocol
     1071      <h3 id="rfc.section.2.7.1"><a href="#rfc.section.2.7.1">2.7.1</a>&nbsp;<a id="message.robustness" href="#message.robustness">Message Parsing Robustness</a></h3>
     1072      <p id="rfc.section.2.7.1.p.1">In the interest of robustness, servers <em class="bcp14">SHOULD</em> ignore at least one empty line received where a Request-Line is expected. In other words, if the server is reading the protocol
    10891073         stream at the beginning of a message and receives a CRLF first, it should ignore the CRLF.
    10901074      </p>
    1091       <p id="rfc.section.3.1.p.2">Some old HTTP/1.0 client implementations generate an extra CRLF after a POST request as a lame workaround for some early server
     1075      <p id="rfc.section.2.7.1.p.2">Some old HTTP/1.0 client implementations generate an extra CRLF after a POST request as a lame workaround for some early server
    10921076         applications that failed to read message-body content that was not terminated by a line-ending. An HTTP/1.1 client <em class="bcp14">MUST NOT</em> preface or follow a request with an extra CRLF. If terminating the request message-body with a line-ending is desired, then
    10931077         the client <em class="bcp14">MUST</em> include the terminating CRLF octets as part of the message-body length.
    10941078      </p>
    1095       <p id="rfc.section.3.1.p.3">The normal procedure for parsing an HTTP message is to read the start-line into a structure, read each header field into a
     1079      <p id="rfc.section.2.7.1.p.3">The normal procedure for parsing an HTTP message is to read the start-line into a structure, read each header field into a
    10961080         hash table by field name until the empty line, and then use the parsed data to determine if a message-body is expected. If
    10971081         a message-body has been indicated, then it is read as a stream until an amount of OCTETs equal to the message-length is read
     
    11001084         security flaws due to the differing ways that such parsers interpret invalid characters.
    11011085      </p>
    1102       <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a>&nbsp;<a id="header.fields" href="#header.fields">Header Fields</a></h2>
    1103       <p id="rfc.section.3.2.p.1">Each HTTP header field consists of a case-insensitive field name followed by a colon (":"), optional whitespace, and the field
     1086      <h3 id="rfc.section.2.7.2"><a href="#rfc.section.2.7.2">2.7.2</a>&nbsp;<a id="header.fields" href="#header.fields">Header Fields</a></h3>
     1087      <p id="rfc.section.2.7.2.p.1">Each HTTP header field consists of a case-insensitive field name followed by a colon (":"), optional whitespace, and the field
    11041088         value.
    11051089      </p>
     
    11081092  <a href="#header.fields" class="smpl">field-value</a>    = *( <a href="#header.fields" class="smpl">field-content</a> / <a href="#rule.whitespace" class="smpl">OWS</a> )
    11091093  <a href="#header.fields" class="smpl">field-content</a>  = *( <a href="#core.rules" class="smpl">WSP</a> / <a href="#core.rules" class="smpl">VCHAR</a> / <a href="#rule.quoted-string" class="smpl">obs-text</a> )
    1110 </pre><p id="rfc.section.3.2.p.3">No whitespace is allowed between the header field name and colon. For security reasons, any request message received containing
     1094</pre><p id="rfc.section.2.7.2.p.3">No whitespace is allowed between the header field name and colon. For security reasons, any request message received containing
    11111095         such whitespace <em class="bcp14">MUST</em> be rejected with a response code of 400 (Bad Request). A proxy <em class="bcp14">MUST</em> remove any such whitespace from a response message before forwarding the message downstream.
    11121096      </p>
    1113       <p id="rfc.section.3.2.p.4">A field value <em class="bcp14">MAY</em> be preceded by optional whitespace (OWS); a single SP is preferred. The field value does not include any leading or trailing
     1097      <p id="rfc.section.2.7.2.p.4">A field value <em class="bcp14">MAY</em> be preceded by optional whitespace (OWS); a single SP is preferred. The field value does not include any leading or trailing
    11141098         white space: OWS occurring before the first non-whitespace character of the field value or after the last non-whitespace character
    11151099         of the field value is ignored and <em class="bcp14">SHOULD</em> be removed without changing the meaning of the header field.
    11161100      </p>
    1117       <p id="rfc.section.3.2.p.5">The order in which header fields with differing field names are received is not significant. However, it is "good practice"
     1101      <p id="rfc.section.2.7.2.p.5">The order in which header fields with differing field names are received is not significant. However, it is "good practice"
    11181102         to send header fields that contain control data first, such as Host on requests and Date on responses, so that implementations
    11191103         can decide when not to handle a message as early as possible. A server <em class="bcp14">MUST</em> wait until the entire header section is received before interpreting a request message, since later header fields might include
    11201104         conditionals, authentication credentials, or deliberately misleading duplicate header fields that would impact request processing.
    11211105      </p>
    1122       <p id="rfc.section.3.2.p.6">Multiple header fields with the same field name <em class="bcp14">MAY</em> be sent in a message if and only if the entire field value for that header field is defined as a comma-separated list [i.e.,
    1123          #(values)]. Multiple header fields with the same field name can be combined into one "field-name: field-value" pair, without
    1124          changing the semantics of the message, by appending each subsequent field value to the combined field value in order, separated
    1125          by a comma. The order in which header fields with the same field name are received is therefore significant to the interpretation
     1106      <p id="rfc.section.2.7.2.p.6">Multiple header fields with the same field name <em class="bcp14">MUST NOT</em> be sent in a message unless the entire field value for that header field is defined as a comma-separated list [i.e., #(values)].
     1107         Multiple header fields with the same field name can be combined into one "field-name: field-value" pair, without changing
     1108         the semantics of the message, by appending each subsequent field value to the combined field value in order, separated by
     1109         a comma. The order in which header fields with the same field name are received is therefore significant to the interpretation
    11261110         of the combined field value; a proxy <em class="bcp14">MUST NOT</em> change the order of these field values when forwarding a message.
    11271111      </p>
     
    11311115         </p>
    11321116      </div>
    1133       <p id="rfc.section.3.2.p.8">Historically, HTTP header field values could be extended over multiple lines by preceding each extra line with at least one
     1117      <p id="rfc.section.2.7.2.p.8">Historically, HTTP header field values could be extended over multiple lines by preceding each extra line with at least one
    11341118         space or horizontal tab character (line folding). This specification deprecates such line folding except within the message/http
    1135          media type (<a href="#internet.media.type.message.http" title="Internet Media Type message/http">Section&nbsp;9.3.1</a>). HTTP/1.1 senders <em class="bcp14">MUST NOT</em> produce messages that include line folding (i.e., that contain any field-content that matches the obs-fold rule) unless the
     1119         media type (<a href="#internet.media.type.message.http" title="Internet Media Type message/http">Section&nbsp;4.3.1</a>). HTTP/1.1 senders <em class="bcp14">MUST NOT</em> produce messages that include line folding (i.e., that contain any field-content that matches the obs-fold rule) unless the
    11361120         message is intended for packaging within the message/http media type. HTTP/1.1 recipients <em class="bcp14">SHOULD</em> accept line folding and replace any embedded obs-fold whitespace with a single SP prior to interpreting the field value or
    11371121         forwarding the message downstream.
    11381122      </p>
    1139       <p id="rfc.section.3.2.p.9">Historically, HTTP has allowed field content with text in the ISO-8859-1 <a href="#ISO-8859-1" id="rfc.xref.ISO-8859-1.1"><cite title="Information technology -- 8-bit single-byte coded graphic character sets -- Part 1: Latin alphabet No. 1">[ISO-8859-1]</cite></a> character encoding and supported other character sets only through use of <a href="#RFC2047" id="rfc.xref.RFC2047.1"><cite title="MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text">[RFC2047]</cite></a> encoding. In practice, most HTTP header field values use only a subset of the US-ASCII character encoding <a href="#USASCII" id="rfc.xref.USASCII.2"><cite title="Coded Character Set -- 7-bit American Standard Code for Information Interchange">[USASCII]</cite></a>. Newly defined header fields <em class="bcp14">SHOULD</em> limit their field values to US-ASCII characters. Recipients <em class="bcp14">SHOULD</em> treat other (obs-text) octets in field content as opaque data.
     1123      <p id="rfc.section.2.7.2.p.9">Historically, HTTP has allowed field content with text in the ISO-8859-1 <a href="#ISO-8859-1" id="rfc.xref.ISO-8859-1.1"><cite title="Information technology -- 8-bit single-byte coded graphic character sets -- Part 1: Latin alphabet No. 1">[ISO-8859-1]</cite></a> character encoding and supported other character sets only through use of <a href="#RFC2047" id="rfc.xref.RFC2047.1"><cite title="MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text">[RFC2047]</cite></a> encoding. In practice, most HTTP header field values use only a subset of the US-ASCII character encoding <a href="#USASCII" id="rfc.xref.USASCII.2"><cite title="Coded Character Set -- 7-bit American Standard Code for Information Interchange">[USASCII]</cite></a>. Newly defined header fields <em class="bcp14">SHOULD</em> limit their field values to US-ASCII characters. Recipients <em class="bcp14">SHOULD</em> treat other (obs-text) octets in field content as opaque data.
    11401124      </p>
    11411125      <div id="rule.comment">
    1142          <p id="rfc.section.3.2.p.10">    Comments can be included in some HTTP header fields by surrounding the comment text with parentheses. Comments are only allowed
     1126         <p id="rfc.section.2.7.2.p.10">    Comments can be included in some HTTP header fields by surrounding the comment text with parentheses. Comments are only allowed
    11431127            in fields containing "comment" as part of their field value definition.
    11441128         </p>
     
    11471131  <a href="#rule.comment" class="smpl">ctext</a>          = <a href="#rule.whitespace" class="smpl">OWS</a> / %x21-27 / %x2A-5B / %x5D-7E / <a href="#rule.quoted-string" class="smpl">obs-text</a>
    11481132                 ; <a href="#rule.whitespace" class="smpl">OWS</a> / &lt;<a href="#core.rules" class="smpl">VCHAR</a> except "(", ")", and "\"&gt; / <a href="#rule.quoted-string" class="smpl">obs-text</a>
    1149 </pre><h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="message.body" href="#message.body">Message Body</a></h2>
    1150       <p id="rfc.section.3.3.p.1">The message-body (if any) of an HTTP message is used to carry the entity-body associated with the request or response. The
     1133</pre><h3 id="rfc.section.2.7.3"><a href="#rfc.section.2.7.3">2.7.3</a>&nbsp;<a id="message.body" href="#message.body">Message Body</a></h3>
     1134      <p id="rfc.section.2.7.3.p.1">The message-body (if any) of an HTTP message is used to carry the entity-body associated with the request or response. The
    11511135         message-body differs from the entity-body only when a transfer-coding has been applied, as indicated by the Transfer-Encoding
    1152          header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.1" title="Transfer-Encoding">Section&nbsp;8.7</a>).
     1136         header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.1" title="Transfer-Encoding">Section&nbsp;3.7</a>).
    11531137      </p>
    11541138      <div id="rfc.figure.u.25"></div><pre class="inline"><span id="rfc.iref.g.42"></span>  <a href="#message.body" class="smpl">message-body</a> = <a href="#abnf.dependencies" class="smpl">entity-body</a>
    11551139               / &lt;entity-body encoded as per <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding</a>&gt;
    1156 </pre><p id="rfc.section.3.3.p.3">Transfer-Encoding <em class="bcp14">MUST</em> be used to indicate any transfer-codings applied by an application to ensure safe and proper transfer of the message. Transfer-Encoding
    1157          is a property of the message, not of the entity, and thus <em class="bcp14">MAY</em> be added or removed by any application along the request/response chain. (However, <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;6.2</a> places restrictions on when certain transfer-codings may be used.)
    1158       </p>
    1159       <p id="rfc.section.3.3.p.4">The rules for when a message-body is allowed in a message differ for requests and responses.</p>
    1160       <p id="rfc.section.3.3.p.5">The presence of a message-body in a request is signaled by the inclusion of a Content-Length or Transfer-Encoding header field
     1140</pre><p id="rfc.section.2.7.3.p.3">Transfer-Encoding <em class="bcp14">MUST</em> be used to indicate any transfer-codings applied by an application to ensure safe and proper transfer of the message. Transfer-Encoding
     1141         is a property of the message, not of the entity, and thus <em class="bcp14">MAY</em> be added or removed by any application along the request/response chain. (However, <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;2.10.2</a> places restrictions on when certain transfer-codings may be used.)
     1142      </p>
     1143      <p id="rfc.section.2.7.3.p.4">The rules for when a message-body is allowed in a message differ for requests and responses.</p>
     1144      <p id="rfc.section.2.7.3.p.5">The presence of a message-body in a request is signaled by the inclusion of a Content-Length or Transfer-Encoding header field
    11611145         in the request's header fields. When a request message contains both a message-body of non-zero length and a method that does
    11621146         not define any semantics for that request message-body, then an origin server <em class="bcp14">SHOULD</em> either ignore the message-body or respond with an appropriate error message (e.g., 413). A proxy or gateway, when presented
    11631147         the same request, <em class="bcp14">SHOULD</em> either forward the request inbound with the message-body or ignore the message-body when determining a response.
    11641148      </p>
    1165       <p id="rfc.section.3.3.p.6">For response messages, whether or not a message-body is included with a message is dependent on both the request method and
    1166          the response status code (<a href="#status.code.and.reason.phrase" title="Status Code and Reason Phrase">Section&nbsp;5.1.1</a>). All responses to the HEAD request method <em class="bcp14">MUST NOT</em> include a message-body, even though the presence of entity-header fields might lead one to believe they do. All 1xx (informational),
     1149      <p id="rfc.section.2.7.3.p.6">For response messages, whether or not a message-body is included with a message is dependent on both the request method and
     1150         the response status code (<a href="#status.code.and.reason.phrase" title="Status Code and Reason Phrase">Section&nbsp;2.9.1.1</a>). All responses to the HEAD request method <em class="bcp14">MUST NOT</em> include a message-body, even though the presence of entity-header fields might lead one to believe they do. All 1xx (informational),
    11671151         204 (No Content), and 304 (Not Modified) responses <em class="bcp14">MUST NOT</em> include a message-body. All other responses do include a message-body, although it <em class="bcp14">MAY</em> be of zero length.
    11681152      </p>
    1169       <h2 id="rfc.section.3.4"><a href="#rfc.section.3.4">3.4</a>&nbsp;<a id="message.length" href="#message.length">Message Length</a></h2>
    1170       <p id="rfc.section.3.4.p.1">The transfer-length of a message is the length of the message-body as it appears in the message; that is, after any transfer-codings
     1153      <h3 id="rfc.section.2.7.4"><a href="#rfc.section.2.7.4">2.7.4</a>&nbsp;<a id="message.length" href="#message.length">Message Length</a></h3>
     1154      <p id="rfc.section.2.7.4.p.1">The transfer-length of a message is the length of the message-body as it appears in the message; that is, after any transfer-codings
    11711155         have been applied. When a message-body is included with a message, the transfer-length of that body is determined by one of
    11721156         the following (in order of precedence):
    11731157      </p>
    1174       <p id="rfc.section.3.4.p.2"> </p>
     1158      <p id="rfc.section.2.7.4.p.2"> </p>
    11751159      <ol>
    11761160         <li>
     
    11801164         </li>
    11811165         <li>
    1182             <p>If a Transfer-Encoding header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.2" title="Transfer-Encoding">Section&nbsp;8.7</a>) is present and the "chunked" transfer-coding (<a href="#transfer.codings" title="Transfer Codings">Section&nbsp;6.2</a>) is used, the transfer-length is defined by the use of this transfer-coding. If a Transfer-Encoding header field is present
     1166            <p>If a Transfer-Encoding header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.2" title="Transfer-Encoding">Section&nbsp;3.7</a>) is present and the "chunked" transfer-coding (<a href="#transfer.codings" title="Transfer Codings">Section&nbsp;2.10.2</a>) is used, the transfer-length is defined by the use of this transfer-coding. If a Transfer-Encoding header field is present
    11831167               and the "chunked" transfer-coding is not present, the transfer-length is defined by the sender closing the connection.
    11841168            </p>
    11851169         </li>
    11861170         <li>
    1187             <p>If a Content-Length header field (<a href="#header.content-length" id="rfc.xref.header.content-length.1" title="Content-Length">Section&nbsp;8.2</a>) is present, its value in OCTETs represents both the entity-length and the transfer-length. The Content-Length header field <em class="bcp14">MUST NOT</em> be sent if these two lengths are different (i.e., if a Transfer-Encoding header field is present). If a message is received
     1171            <p>If a Content-Length header field (<a href="#header.content-length" id="rfc.xref.header.content-length.1" title="Content-Length">Section&nbsp;3.2</a>) is present, its value in OCTETs represents both the entity-length and the transfer-length. The Content-Length header field <em class="bcp14">MUST NOT</em> be sent if these two lengths are different (i.e., if a Transfer-Encoding header field is present). If a message is received
    11881172               with both a Transfer-Encoding header field and a Content-Length header field, the latter <em class="bcp14">MUST</em> be ignored.
    11891173            </p>
     
    12051189         </li>
    12061190      </ol>
    1207       <p id="rfc.section.3.4.p.3">For compatibility with HTTP/1.0 applications, HTTP/1.1 requests containing a message-body <em class="bcp14">MUST</em> include a valid Content-Length header field unless the server is known to be HTTP/1.1 compliant. If a request contains a message-body
     1191      <p id="rfc.section.2.7.4.p.3">For compatibility with HTTP/1.0 applications, HTTP/1.1 requests containing a message-body <em class="bcp14">MUST</em> include a valid Content-Length header field unless the server is known to be HTTP/1.1 compliant. If a request contains a message-body
    12081192         and a Content-Length is not given, the server <em class="bcp14">SHOULD</em> respond with 400 (Bad Request) if it cannot determine the length of the message, or with 411 (Length Required) if it wishes
    12091193         to insist on receiving a valid Content-Length.
    12101194      </p>
    1211       <p id="rfc.section.3.4.p.4">All HTTP/1.1 applications that receive entities <em class="bcp14">MUST</em> accept the "chunked" transfer-coding (<a href="#transfer.codings" title="Transfer Codings">Section&nbsp;6.2</a>), thus allowing this mechanism to be used for messages when the message length cannot be determined in advance.
    1212       </p>
    1213       <p id="rfc.section.3.4.p.5">Messages <em class="bcp14">MUST NOT</em> include both a Content-Length header field and a transfer-coding. If the message does include a transfer-coding, the Content-Length <em class="bcp14">MUST</em> be ignored.
    1214       </p>
    1215       <p id="rfc.section.3.4.p.6">When a Content-Length is given in a message where a message-body is allowed, its field value <em class="bcp14">MUST</em> exactly match the number of OCTETs in the message-body. HTTP/1.1 user agents <em class="bcp14">MUST</em> notify the user when an invalid length is received and detected.
    1216       </p>
    1217       <h2 id="rfc.section.3.5"><a href="#rfc.section.3.5">3.5</a>&nbsp;<a id="general.header.fields" href="#general.header.fields">General Header Fields</a></h2>
    1218       <p id="rfc.section.3.5.p.1">There are a few header fields which have general applicability for both request and response messages, but which do not apply
     1195      <p id="rfc.section.2.7.4.p.4">All HTTP/1.1 applications that receive entities <em class="bcp14">MUST</em> accept the "chunked" transfer-coding (<a href="#transfer.codings" title="Transfer Codings">Section&nbsp;2.10.2</a>), thus allowing this mechanism to be used for messages when the message length cannot be determined in advance.
     1196      </p>
     1197      <p id="rfc.section.2.7.4.p.5">Messages <em class="bcp14">MUST NOT</em> include both a Content-Length header field and a transfer-coding. If the message does include a transfer-coding, the Content-Length <em class="bcp14">MUST</em> be ignored.
     1198      </p>
     1199      <p id="rfc.section.2.7.4.p.6">When a Content-Length is given in a message where a message-body is allowed, its field value <em class="bcp14">MUST</em> exactly match the number of OCTETs in the message-body. HTTP/1.1 user agents <em class="bcp14">MUST</em> notify the user when an invalid length is received and detected.
     1200      </p>
     1201      <h3 id="rfc.section.2.7.5"><a href="#rfc.section.2.7.5">2.7.5</a>&nbsp;<a id="general.header.fields" href="#general.header.fields">General Header Fields</a></h3>
     1202      <p id="rfc.section.2.7.5.p.1">There are a few header fields which have general applicability for both request and response messages, but which do not apply
    12191203         to the entity being transferred. These header fields apply only to the message being transmitted.
    12201204      </p>
    12211205      <div id="rfc.figure.u.26"></div><pre class="inline"><span id="rfc.iref.g.43"></span>  <a href="#general.header.fields" class="smpl">general-header</a> = <a href="#abnf.dependencies" class="smpl">Cache-Control</a>            ; <a href="#Part6" id="rfc.xref.Part6.5"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>, <a href="p6-cache.html#header.cache-control" title="Cache-Control">Section 3.2</a>
    1222                  / <a href="#header.connection" class="smpl">Connection</a>               ; <a href="#header.connection" id="rfc.xref.header.connection.1" title="Connection">Section&nbsp;8.1</a>
    1223                  / <a href="#header.date" class="smpl">Date</a>                     ; <a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section&nbsp;8.3</a>
     1206                 / <a href="#header.connection" class="smpl">Connection</a>               ; <a href="#header.connection" id="rfc.xref.header.connection.1" title="Connection">Section&nbsp;3.1</a>
     1207                 / <a href="#header.date" class="smpl">Date</a>                     ; <a href="#header.date" id="rfc.xref.header.date.1" title="Date">Section&nbsp;3.3</a>
    12241208                 / <a href="#abnf.dependencies" class="smpl">Pragma</a>                   ; <a href="#Part6" id="rfc.xref.Part6.6"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>, <a href="p6-cache.html#header.pragma" title="Pragma">Section 3.4</a>
    1225                  / <a href="#header.trailer" class="smpl">Trailer</a>                  ; <a href="#header.trailer" id="rfc.xref.header.trailer.1" title="Trailer">Section&nbsp;8.6</a>
    1226                  / <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding</a>        ; <a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.3" title="Transfer-Encoding">Section&nbsp;8.7</a>
    1227                  / <a href="#header.upgrade" class="smpl">Upgrade</a>                  ; <a href="#header.upgrade" id="rfc.xref.header.upgrade.1" title="Upgrade">Section&nbsp;8.8</a>
    1228                  / <a href="#header.via" class="smpl">Via</a>                      ; <a href="#header.via" id="rfc.xref.header.via.1" title="Via">Section&nbsp;8.9</a>
     1209                 / <a href="#header.trailer" class="smpl">Trailer</a>                  ; <a href="#header.trailer" id="rfc.xref.header.trailer.1" title="Trailer">Section&nbsp;3.6</a>
     1210                 / <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding</a>        ; <a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.3" title="Transfer-Encoding">Section&nbsp;3.7</a>
     1211                 / <a href="#header.upgrade" class="smpl">Upgrade</a>                  ; <a href="#header.upgrade" id="rfc.xref.header.upgrade.1" title="Upgrade">Section&nbsp;3.8</a>
     1212                 / <a href="#header.via" class="smpl">Via</a>                      ; <a href="#header.via" id="rfc.xref.header.via.1" title="Via">Section&nbsp;3.9</a>
    12291213                 / <a href="#abnf.dependencies" class="smpl">Warning</a>                  ; <a href="#Part6" id="rfc.xref.Part6.7"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>, <a href="p6-cache.html#header.warning" title="Warning">Section 3.6</a>
    1230 </pre><p id="rfc.section.3.5.p.3">General-header field names can be extended reliably only in combination with a change in the protocol version. However, new
     1214</pre><p id="rfc.section.2.7.5.p.3">General-header field names can be extended reliably only in combination with a change in the protocol version. However, new
    12311215         or experimental header fields may be given the semantics of general header fields if all parties in the communication recognize
    12321216         them to be general-header fields. Unrecognized header fields are treated as entity-header fields.
    12331217      </p>
    1234       <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="request" href="#request">Request</a></h1>
    1235       <p id="rfc.section.4.p.1">A request message from a client to a server includes, within the first line of that message, the method to be applied to the
     1218      <h2 id="rfc.section.2.8"><a href="#rfc.section.2.8">2.8</a>&nbsp;<a id="request" href="#request">Request</a></h2>
     1219      <p id="rfc.section.2.8.p.1">A request message from a client to a server includes, within the first line of that message, the method to be applied to the
    12361220         resource, the identifier of the resource, and the protocol version in use.
    12371221      </p>
    1238       <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.44"></span>  <a href="#request" class="smpl">Request</a>       = <a href="#request-line" class="smpl">Request-Line</a>              ; <a href="#request-line" title="Request-Line">Section&nbsp;4.1</a>
    1239                   *(( <a href="#general.header.fields" class="smpl">general-header</a>        ; <a href="#general.header.fields" title="General Header Fields">Section&nbsp;3.5</a>
     1222      <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.44"></span>  <a href="#request" class="smpl">Request</a>       = <a href="#request-line" class="smpl">Request-Line</a>              ; <a href="#request-line" title="Request-Line">Section&nbsp;2.8.1</a>
     1223                  *(( <a href="#general.header.fields" class="smpl">general-header</a>        ; <a href="#general.header.fields" title="General Header Fields">Section&nbsp;2.7.5</a>
    12401224                   / <a href="#abnf.dependencies" class="smpl">request-header</a>         ; <a href="#Part2" id="rfc.xref.Part2.3"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>, <a href="p2-semantics.html#request.header.fields" title="Request Header Fields">Section 3</a>
    12411225                   / <a href="#abnf.dependencies" class="smpl">entity-header</a> ) <a href="#core.rules" class="smpl">CRLF</a> ) ; <a href="#Part3" id="rfc.xref.Part3.5"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>, <a href="p3-payload.html#entity.header.fields" title="Entity Header Fields">Section 3.1</a>
    12421226                  <a href="#core.rules" class="smpl">CRLF</a>
    1243                   [ <a href="#message.body" class="smpl">message-body</a> ]          ; <a href="#message.body" title="Message Body">Section&nbsp;3.3</a>
    1244 </pre><h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a>&nbsp;<a id="request-line" href="#request-line">Request-Line</a></h2>
    1245       <p id="rfc.section.4.1.p.1">The Request-Line begins with a method token, followed by the request-target and the protocol version, and ending with CRLF.
     1227                  [ <a href="#message.body" class="smpl">message-body</a> ]          ; <a href="#message.body" title="Message Body">Section&nbsp;2.7.3</a>
     1228</pre><h3 id="rfc.section.2.8.1"><a href="#rfc.section.2.8.1">2.8.1</a>&nbsp;<a id="request-line" href="#request-line">Request-Line</a></h3>
     1229      <p id="rfc.section.2.8.1.p.1">The Request-Line begins with a method token, followed by the request-target and the protocol version, and ending with CRLF.
    12461230         The elements are separated by SP characters. No CR or LF is allowed except in the final CRLF sequence.
    12471231      </p>
    12481232      <div id="rfc.figure.u.28"></div><pre class="inline"><span id="rfc.iref.g.45"></span>  <a href="#request-line" class="smpl">Request-Line</a>   = <a href="#method" class="smpl">Method</a> <a href="#core.rules" class="smpl">SP</a> <a href="#request-target" class="smpl">request-target</a> <a href="#core.rules" class="smpl">SP</a> <a href="#http.version" class="smpl">HTTP-Version</a> <a href="#core.rules" class="smpl">CRLF</a>
    1249 </pre><h3 id="rfc.section.4.1.1"><a href="#rfc.section.4.1.1">4.1.1</a>&nbsp;<a id="method" href="#method">Method</a></h3>
    1250       <p id="rfc.section.4.1.1.p.1">The Method token indicates the method to be performed on the resource identified by the request-target. The method is case-sensitive.</p>
     1233</pre><h4 id="rfc.section.2.8.1.1"><a href="#rfc.section.2.8.1.1">2.8.1.1</a>&nbsp;<a id="method" href="#method">Method</a></h4>
     1234      <p id="rfc.section.2.8.1.1.p.1">The Method token indicates the method to be performed on the resource identified by the request-target. The method is case-sensitive.</p>
    12511235      <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.46"></span><span id="rfc.iref.g.47"></span>  <a href="#method" class="smpl">Method</a>         = <a href="#rule.token.separators" class="smpl">token</a>
    1252 </pre><h3 id="rfc.section.4.1.2"><a href="#rfc.section.4.1.2">4.1.2</a>&nbsp;<a id="request-target" href="#request-target">request-target</a></h3>
    1253       <p id="rfc.section.4.1.2.p.1">The request-target identifies the resource upon which to apply the request.</p>
     1236</pre><h4 id="rfc.section.2.8.1.2"><a href="#rfc.section.2.8.1.2">2.8.1.2</a>&nbsp;<a id="request-target" href="#request-target">request-target</a></h4>
     1237      <p id="rfc.section.2.8.1.2.p.1">The request-target identifies the resource upon which to apply the request.</p>
    12541238      <div id="rfc.figure.u.30"></div><pre class="inline"><span id="rfc.iref.g.48"></span>  <a href="#request-target" class="smpl">request-target</a> = "*"
    12551239                 / <a href="#uri" class="smpl">absolute-URI</a>
    12561240                 / ( <a href="#uri" class="smpl">path-absolute</a> [ "?" <a href="#uri" class="smpl">query</a> ] )
    12571241                 / <a href="#uri" class="smpl">authority</a>
    1258 </pre><p id="rfc.section.4.1.2.p.3">The four options for request-target are dependent on the nature of the request. The asterisk "*" means that the request does
     1242</pre><p id="rfc.section.2.8.1.2.p.3">The four options for request-target are dependent on the nature of the request. The asterisk "*" means that the request does
    12591243         not apply to a particular resource, but to the server itself, and is only allowed when the method used does not necessarily
    12601244         apply to a resource. One example would be
    12611245      </p>
    12621246      <div id="rfc.figure.u.31"></div><pre class="text">  OPTIONS * HTTP/1.1
    1263 </pre><p id="rfc.section.4.1.2.p.5">The absolute-URI form is <em class="bcp14">REQUIRED</em> when the request is being made to a proxy. The proxy is requested to forward the request or service it from a valid cache,
     1247</pre><p id="rfc.section.2.8.1.2.p.5">The absolute-URI form is <em class="bcp14">REQUIRED</em> when the request is being made to a proxy. The proxy is requested to forward the request or service it from a valid cache,
    12641248         and return the response. Note that the proxy <em class="bcp14">MAY</em> forward the request on to another proxy or directly to the server specified by the absolute-URI. In order to avoid request
    12651249         loops, a proxy <em class="bcp14">MUST</em> be able to recognize all of its server names, including any aliases, local variations, and the numeric IP address. An example
     
    12671251      </p>
    12681252      <div id="rfc.figure.u.32"></div><pre class="text">  GET http://www.example.org/pub/WWW/TheProject.html HTTP/1.1
    1269 </pre><p id="rfc.section.4.1.2.p.7">To allow for transition to absolute-URIs in all requests in future versions of HTTP, all HTTP/1.1 servers <em class="bcp14">MUST</em> accept the absolute-URI form in requests, even though HTTP/1.1 clients will only generate them in requests to proxies.
    1270       </p>
    1271       <p id="rfc.section.4.1.2.p.8">The authority form is only used by the CONNECT method (<a href="p2-semantics.html#CONNECT" title="CONNECT">Section 7.9</a> of <a href="#Part2" id="rfc.xref.Part2.4"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>).
    1272       </p>
    1273       <p id="rfc.section.4.1.2.p.9">The most common form of request-target is that used to identify a resource on an origin server or gateway. In this case the
     1253</pre><p id="rfc.section.2.8.1.2.p.7">To allow for transition to absolute-URIs in all requests in future versions of HTTP, all HTTP/1.1 servers <em class="bcp14">MUST</em> accept the absolute-URI form in requests, even though HTTP/1.1 clients will only generate them in requests to proxies.
     1254      </p>
     1255      <p id="rfc.section.2.8.1.2.p.8">The authority form is only used by the CONNECT method (<a href="p2-semantics.html#CONNECT" title="CONNECT">Section 7.9</a> of <a href="#Part2" id="rfc.xref.Part2.4"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>).
     1256      </p>
     1257      <p id="rfc.section.2.8.1.2.p.9">The most common form of request-target is that used to identify a resource on an origin server or gateway. In this case the
    12741258         absolute path of the URI <em class="bcp14">MUST</em> be transmitted (see <a href="#http.uri" title="http URI scheme">Section&nbsp;2.6.1</a>, path-absolute) as the request-target, and the network location of the URI (authority) <em class="bcp14">MUST</em> be transmitted in a Host header field. For example, a client wishing to retrieve the resource above directly from the origin
    12751259         server would create a TCP connection to port 80 of the host "www.example.org" and send the lines:
     
    12771261      <div id="rfc.figure.u.33"></div><pre class="text">  GET /pub/WWW/TheProject.html HTTP/1.1
    12781262  Host: www.example.org
    1279 </pre><p id="rfc.section.4.1.2.p.11">followed by the remainder of the Request. Note that the absolute path cannot be empty; if none is present in the original
     1263</pre><p id="rfc.section.2.8.1.2.p.11">followed by the remainder of the Request. Note that the absolute path cannot be empty; if none is present in the original
    12801264         URI, it <em class="bcp14">MUST</em> be given as "/" (the server root).
    12811265      </p>
    1282       <p id="rfc.section.4.1.2.p.12">If a proxy receives a request without any path in the request-target and the method specified is capable of supporting the
     1266      <p id="rfc.section.2.8.1.2.p.12">If a proxy receives a request without any path in the request-target and the method specified is capable of supporting the
    12831267         asterisk form of request-target, then the last proxy on the request chain <em class="bcp14">MUST</em> forward the request with "*" as the final request-target.
    12841268      </p>
     
    12891273  Host: www.example.org:8001
    12901274</pre>  <p>after connecting to port 8001 of host "www.example.org".</p>
    1291       <p id="rfc.section.4.1.2.p.15">The request-target is transmitted in the format specified in <a href="#http.uri" title="http URI scheme">Section&nbsp;2.6.1</a>. If the request-target is percent-encoded (<a href="#RFC3986" id="rfc.xref.RFC3986.18"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-2.1">Section 2.1</a>), the origin server <em class="bcp14">MUST</em> decode the request-target in order to properly interpret the request. Servers <em class="bcp14">SHOULD</em> respond to invalid request-targets with an appropriate status code.
    1292       </p>
    1293       <p id="rfc.section.4.1.2.p.16">A transparent proxy <em class="bcp14">MUST NOT</em> rewrite the "path-absolute" part of the received request-target when forwarding it to the next inbound server, except as noted
     1275      <p id="rfc.section.2.8.1.2.p.15">The request-target is transmitted in the format specified in <a href="#http.uri" title="http URI scheme">Section&nbsp;2.6.1</a>. If the request-target is percent-encoded (<a href="#RFC3986" id="rfc.xref.RFC3986.18"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-2.1">Section 2.1</a>), the origin server <em class="bcp14">MUST</em> decode the request-target in order to properly interpret the request. Servers <em class="bcp14">SHOULD</em> respond to invalid request-targets with an appropriate status code.
     1276      </p>
     1277      <p id="rfc.section.2.8.1.2.p.16">A transparent proxy <em class="bcp14">MUST NOT</em> rewrite the "path-absolute" part of the received request-target when forwarding it to the next inbound server, except as noted
    12941278         above to replace a null path-absolute with "/".
    12951279      </p>
     
    13001284         </p>
    13011285      </div>
    1302       <p id="rfc.section.4.1.2.p.18">HTTP does not place a pre-defined limit on the length of a request-target. A server <em class="bcp14">MUST</em> be prepared to receive URIs of unbounded length and respond with the 414 (URI Too Long) status if the received request-target
     1286      <p id="rfc.section.2.8.1.2.p.18">HTTP does not place a pre-defined limit on the length of a request-target. A server <em class="bcp14">MUST</em> be prepared to receive URIs of unbounded length and respond with the 414 (URI Too Long) status if the received request-target
    13031287         would be longer than the server wishes to handle (see <a href="p2-semantics.html#status.414" title="414 URI Too Long">Section 8.4.15</a> of <a href="#Part2" id="rfc.xref.Part2.5"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>).
    13041288      </p>
    1305       <p id="rfc.section.4.1.2.p.19">Various ad-hoc limitations on request-target length are found in practice. It is <em class="bcp14">RECOMMENDED</em> that all HTTP senders and recipients support request-target lengths of 8000 or more OCTETs.
    1306       </p>
    1307       <h2 id="rfc.section.4.2"><a href="#rfc.section.4.2">4.2</a>&nbsp;<a id="the.resource.identified.by.a.request" href="#the.resource.identified.by.a.request">The Resource Identified by a Request</a></h2>
    1308       <p id="rfc.section.4.2.p.1">The exact resource identified by an Internet request is determined by examining both the request-target and the Host header
     1289      <p id="rfc.section.2.8.1.2.p.19">Various ad-hoc limitations on request-target length are found in practice. It is <em class="bcp14">RECOMMENDED</em> that all HTTP senders and recipients support request-target lengths of 8000 or more OCTETs.
     1290      </p>
     1291      <h3 id="rfc.section.2.8.2"><a href="#rfc.section.2.8.2">2.8.2</a>&nbsp;<a id="the.resource.identified.by.a.request" href="#the.resource.identified.by.a.request">The Resource Identified by a Request</a></h3>
     1292      <p id="rfc.section.2.8.2.p.1">The exact resource identified by an Internet request is determined by examining both the request-target and the Host header
    13091293         field.
    13101294      </p>
    1311       <p id="rfc.section.4.2.p.2">An origin server that does not allow resources to differ by the requested host <em class="bcp14">MAY</em> ignore the Host header field value when determining the resource identified by an HTTP/1.1 request. (But see <a href="#changes.to.simplify.multi-homed.web.servers.and.conserve.ip.addresses" title="Changes to Simplify Multi-homed Web Servers and Conserve IP Addresses">Appendix&nbsp;B.1.1</a> for other requirements on Host support in HTTP/1.1.)
    1312       </p>
    1313       <p id="rfc.section.4.2.p.3">An origin server that does differentiate resources based on the host requested (sometimes referred to as virtual hosts or
     1295      <p id="rfc.section.2.8.2.p.2">An origin server that does not allow resources to differ by the requested host <em class="bcp14">MAY</em> ignore the Host header field value when determining the resource identified by an HTTP/1.1 request. (But see <a href="#changes.to.simplify.multi-homed.web.servers.and.conserve.ip.addresses" title="Changes to Simplify Multi-homed Web Servers and Conserve IP Addresses">Appendix&nbsp;B.1.1</a> for other requirements on Host support in HTTP/1.1.)
     1296      </p>
     1297      <p id="rfc.section.2.8.2.p.3">An origin server that does differentiate resources based on the host requested (sometimes referred to as virtual hosts or
    13141298         vanity host names) <em class="bcp14">MUST</em> use the following rules for determining the requested resource on an HTTP/1.1 request:
    13151299      </p>
     
    13231307         </li>
    13241308      </ol>
    1325       <p id="rfc.section.4.2.p.4">Recipients of an HTTP/1.0 request that lacks a Host header field <em class="bcp14">MAY</em> attempt to use heuristics (e.g., examination of the URI path for something unique to a particular host) in order to determine
     1309      <p id="rfc.section.2.8.2.p.4">Recipients of an HTTP/1.0 request that lacks a Host header field <em class="bcp14">MAY</em> attempt to use heuristics (e.g., examination of the URI path for something unique to a particular host) in order to determine
    13261310         what exact resource is being requested.
    13271311      </p>
    1328       <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="response" href="#response">Response</a></h1>
    1329       <p id="rfc.section.5.p.1">After receiving and interpreting a request message, a server responds with an HTTP response message.</p>
    1330       <div id="rfc.figure.u.36"></div><pre class="inline"><span id="rfc.iref.g.49"></span>  <a href="#response" class="smpl">Response</a>      = <a href="#status-line" class="smpl">Status-Line</a>               ; <a href="#status-line" title="Status-Line">Section&nbsp;5.1</a>
    1331                   *(( <a href="#general.header.fields" class="smpl">general-header</a>        ; <a href="#general.header.fields" title="General Header Fields">Section&nbsp;3.5</a>
     1312      <h2 id="rfc.section.2.9"><a href="#rfc.section.2.9">2.9</a>&nbsp;<a id="response" href="#response">Response</a></h2>
     1313      <p id="rfc.section.2.9.p.1">After receiving and interpreting a request message, a server responds with an HTTP response message.</p>
     1314      <div id="rfc.figure.u.36"></div><pre class="inline"><span id="rfc.iref.g.49"></span>  <a href="#response" class="smpl">Response</a>      = <a href="#status-line" class="smpl">Status-Line</a>               ; <a href="#status-line" title="Status-Line">Section&nbsp;2.9.1</a>
     1315                  *(( <a href="#general.header.fields" class="smpl">general-header</a>        ; <a href="#general.header.fields" title="General Header Fields">Section&nbsp;2.7.5</a>
    13321316                   / <a href="#abnf.dependencies" class="smpl">response-header</a>        ; <a href="#Part2" id="rfc.xref.Part2.6"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>, <a href="p2-semantics.html#response.header.fields" title="Response Header Fields">Section 5</a>
    13331317                   / <a href="#abnf.dependencies" class="smpl">entity-header</a> ) <a href="#core.rules" class="smpl">CRLF</a> )  ; <a href="#Part3" id="rfc.xref.Part3.6"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>, <a href="p3-payload.html#entity.header.fields" title="Entity Header Fields">Section 3.1</a>
    13341318                  <a href="#core.rules" class="smpl">CRLF</a>
    1335                   [ <a href="#message.body" class="smpl">message-body</a> ]          ; <a href="#message.body" title="Message Body">Section&nbsp;3.3</a>
    1336 </pre><h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a>&nbsp;<a id="status-line" href="#status-line">Status-Line</a></h2>
    1337       <p id="rfc.section.5.1.p.1">The first line of a Response message is the Status-Line, consisting of the protocol version followed by a numeric status code
     1319                  [ <a href="#message.body" class="smpl">message-body</a> ]          ; <a href="#message.body" title="Message Body">Section&nbsp;2.7.3</a>
     1320</pre><h3 id="rfc.section.2.9.1"><a href="#rfc.section.2.9.1">2.9.1</a>&nbsp;<a id="status-line" href="#status-line">Status-Line</a></h3>
     1321      <p id="rfc.section.2.9.1.p.1">The first line of a Response message is the Status-Line, consisting of the protocol version followed by a numeric status code
    13381322         and its associated textual phrase, with each element separated by SP characters. No CR or LF is allowed except in the final
    13391323         CRLF sequence.
    13401324      </p>
    13411325      <div id="rfc.figure.u.37"></div><pre class="inline"><span id="rfc.iref.g.50"></span>  <a href="#status-line" class="smpl">Status-Line</a> = <a href="#http.version" class="smpl">HTTP-Version</a> <a href="#core.rules" class="smpl">SP</a> <a href="#status.code.and.reason.phrase" class="smpl">Status-Code</a> <a href="#core.rules" class="smpl">SP</a> <a href="#status.code.and.reason.phrase" class="smpl">Reason-Phrase</a> <a href="#core.rules" class="smpl">CRLF</a>
    1342 </pre><h3 id="rfc.section.5.1.1"><a href="#rfc.section.5.1.1">5.1.1</a>&nbsp;<a id="status.code.and.reason.phrase" href="#status.code.and.reason.phrase">Status Code and Reason Phrase</a></h3>
    1343       <p id="rfc.section.5.1.1.p.1">The Status-Code element is a 3-digit integer result code of the attempt to understand and satisfy the request. These codes
     1326</pre><h4 id="rfc.section.2.9.1.1"><a href="#rfc.section.2.9.1.1">2.9.1.1</a>&nbsp;<a id="status.code.and.reason.phrase" href="#status.code.and.reason.phrase">Status Code and Reason Phrase</a></h4>
     1327      <p id="rfc.section.2.9.1.1.p.1">The Status-Code element is a 3-digit integer result code of the attempt to understand and satisfy the request. These codes
    13441328         are fully defined in <a href="p2-semantics.html#status.codes" title="Status Code Definitions">Section 8</a> of <a href="#Part2" id="rfc.xref.Part2.7"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>. The Reason Phrase exists for the sole purpose of providing a textual description associated with the numeric status code,
    13451329         out of deference to earlier Internet application protocols that were more frequently used with interactive text clients. A
    13461330         client <em class="bcp14">SHOULD</em> ignore the content of the Reason Phrase.
    13471331      </p>
    1348       <p id="rfc.section.5.1.1.p.2">The first digit of the Status-Code defines the class of response. The last two digits do not have any categorization role.
     1332      <p id="rfc.section.2.9.1.1.p.2">The first digit of the Status-Code defines the class of response. The last two digits do not have any categorization role.
    13491333         There are 5 values for the first digit:
    13501334      </p>
     
    13581342      <div id="rfc.figure.u.38"></div><pre class="inline"><span id="rfc.iref.g.51"></span><span id="rfc.iref.g.52"></span><span id="rfc.iref.g.53"></span>  <a href="#status.code.and.reason.phrase" class="smpl">Status-Code</a>    = 3<a href="#core.rules" class="smpl">DIGIT</a>
    13591343  <a href="#status.code.and.reason.phrase" class="smpl">Reason-Phrase</a>  = *( <a href="#core.rules" class="smpl">WSP</a> / <a href="#core.rules" class="smpl">VCHAR</a> / <a href="#rule.quoted-string" class="smpl">obs-text</a> )
    1360 </pre><h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h1>
    1361       <h2 id="rfc.section.6.1"><a href="#rfc.section.6.1">6.1</a>&nbsp;<a id="date.time.formats.full.date" href="#date.time.formats.full.date">Date/Time Formats: Full Date</a></h2>
    1362       <p id="rfc.section.6.1.p.1">HTTP applications have historically allowed three different formats for the representation of date/time stamps:</p>
     1344</pre><h2 id="rfc.section.2.10"><a href="#rfc.section.2.10">2.10</a>&nbsp;<a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h2>
     1345      <h3 id="rfc.section.2.10.1"><a href="#rfc.section.2.10.1">2.10.1</a>&nbsp;<a id="date.time.formats.full.date" href="#date.time.formats.full.date">Date/Time Formats: Full Date</a></h3>
     1346      <p id="rfc.section.2.10.1.p.1">HTTP applications have historically allowed three different formats for the representation of date/time stamps:</p>
    13631347      <div id="rfc.figure.u.39"></div><pre class="text">  Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
    13641348  Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format
    13651349  Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format
    1366 </pre><p id="rfc.section.6.1.p.3">The first format is preferred as an Internet standard and represents 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>. The other formats are described here only for compatibility with obsolete implementations. HTTP/1.1 clients and servers
     1350</pre><p id="rfc.section.2.10.1.p.3">The first format is preferred as an Internet standard and represents 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>. The other formats are described here only for compatibility with obsolete implementations. HTTP/1.1 clients and servers
    13671351         that parse the 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. See <a href="#tolerant.applications" title="Tolerant Applications">Appendix&nbsp;A</a> for further information.
    13681352      </p>
    1369       <p id="rfc.section.6.1.p.4">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
     1353      <p id="rfc.section.2.10.1.p.4">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
    13701354         Universal Time). This is indicated in the first two formats by the inclusion of "GMT" as the three-letter abbreviation for
    13711355         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.
     
    13731357      <div id="rfc.figure.u.40"></div><pre class="inline"><span id="rfc.iref.g.54"></span>  <a href="#date.time.formats.full.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>
    13741358</pre><div id="preferred.date.format">
    1375          <p id="rfc.section.6.1.p.6">                    Preferred format:</p>
     1359         <p id="rfc.section.2.10.1.p.6">                    Preferred format:</p>
    13761360      </div>
    13771361      <div id="rfc.figure.u.41"></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><span id="rfc.iref.g.58"></span><span id="rfc.iref.g.59"></span><span id="rfc.iref.g.60"></span><span id="rfc.iref.g.61"></span><span id="rfc.iref.g.62"></span><span id="rfc.iref.g.63"></span><span id="rfc.iref.g.64"></span><span id="rfc.iref.g.65"></span><span id="rfc.iref.g.66"></span>  <a href="#preferred.date.format" class="smpl">rfc1123-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> "," <a href="#core.rules" class="smpl">SP</a> date1 <a href="#core.rules" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#core.rules" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
     
    14111395  <a href="#preferred.date.format" class="smpl">minute</a>       = 2<a href="#core.rules" class="smpl">DIGIT</a>               
    14121396  <a href="#preferred.date.format" class="smpl">second</a>       = 2<a href="#core.rules" class="smpl">DIGIT</a>               
    1413 </pre><p id="rfc.section.6.1.p.8">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>).
     1397</pre><p id="rfc.section.2.10.1.p.8">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>).
    14141398      </p>
    14151399      <div id="obsolete.date.formats">
    1416          <p id="rfc.section.6.1.p.9">                Obsolete formats:</p>
     1400         <p id="rfc.section.2.10.1.p.9">                Obsolete formats:</p>
    14171401      </div>
    14181402      <div id="rfc.figure.u.42"></div><pre class="inline"><span id="rfc.iref.g.67"></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>
     
    14411425         </p>
    14421426      </div>
    1443       <h2 id="rfc.section.6.2"><a href="#rfc.section.6.2">6.2</a>&nbsp;<a id="transfer.codings" href="#transfer.codings">Transfer Codings</a></h2>
    1444       <p id="rfc.section.6.2.p.1">Transfer-coding values are used to indicate an encoding transformation that has been, can be, or may need to be applied to
     1427      <h3 id="rfc.section.2.10.2"><a href="#rfc.section.2.10.2">2.10.2</a>&nbsp;<a id="transfer.codings" href="#transfer.codings">Transfer Codings</a></h3>
     1428      <p id="rfc.section.2.10.2.p.1">Transfer-coding values are used to indicate an encoding transformation that has been, can be, or may need to be applied to
    14451429         an entity-body in order to ensure "safe transport" through the network. This differs from a content coding in that the transfer-coding
    14461430         is a property of the message, not of the original entity.
     
    14491433  <a href="#transfer.codings" class="smpl">transfer-extension</a>      = <a href="#rule.token.separators" class="smpl">token</a> *( <a href="#rule.whitespace" class="smpl">OWS</a> ";" <a href="#rule.whitespace" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">transfer-parameter</a> )
    14501434</pre><div id="rule.parameter">
    1451          <p id="rfc.section.6.2.p.3">      Parameters are in the form of attribute/value pairs.</p>
     1435         <p id="rfc.section.2.10.2.p.3">      Parameters are in the form of attribute/value pairs.</p>
    14521436      </div>
    14531437      <div id="rfc.figure.u.46"></div><pre class="inline"><span id="rfc.iref.g.72"></span><span id="rfc.iref.g.73"></span><span id="rfc.iref.g.74"></span><span id="rfc.iref.g.75"></span><span id="rfc.iref.g.76"></span>  <a href="#rule.parameter" class="smpl">transfer-parameter</a>      = <a href="#rule.parameter" class="smpl">attribute</a> <a href="#rule.whitespace" class="smpl">BWS</a> "=" <a href="#rule.whitespace" class="smpl">BWS</a> <a href="#rule.parameter" class="smpl">value</a>
    14541438  <a href="#rule.parameter" class="smpl">attribute</a>               = <a href="#rule.token.separators" class="smpl">token</a>
    14551439  <a href="#rule.parameter" class="smpl">value</a>                   = <a href="#rule.token.separators" class="smpl">token</a> / <a href="#rule.quoted-string" class="smpl">quoted-string</a>
    1456 </pre><p id="rfc.section.6.2.p.5">All transfer-coding values are case-insensitive. HTTP/1.1 uses transfer-coding values in the TE header field (<a href="#header.te" id="rfc.xref.header.te.1" title="TE">Section&nbsp;8.5</a>) and in the Transfer-Encoding header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.4" title="Transfer-Encoding">Section&nbsp;8.7</a>).
    1457       </p>
    1458       <p id="rfc.section.6.2.p.6">Whenever a transfer-coding is applied to a message-body, the set of transfer-codings <em class="bcp14">MUST</em> include "chunked", unless the message indicates it is terminated by closing the connection. When the "chunked" transfer-coding
     1440</pre><p id="rfc.section.2.10.2.p.5">All transfer-coding values are case-insensitive. HTTP/1.1 uses transfer-coding values in the TE header field (<a href="#header.te" id="rfc.xref.header.te.1" title="TE">Section&nbsp;3.5</a>) and in the Transfer-Encoding header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.4" title="Transfer-Encoding">Section&nbsp;3.7</a>).
     1441      </p>
     1442      <p id="rfc.section.2.10.2.p.6">Whenever a transfer-coding is applied to a message-body, the set of transfer-codings <em class="bcp14">MUST</em> include "chunked", unless the message indicates it is terminated by closing the connection. When the "chunked" transfer-coding
    14591443         is used, it <em class="bcp14">MUST</em> be the last transfer-coding applied to the message-body. The "chunked" transfer-coding <em class="bcp14">MUST NOT</em> be applied more than once to a message-body. These rules allow the recipient to determine the transfer-length of the message
    1460          (<a href="#message.length" title="Message Length">Section&nbsp;3.4</a>).
    1461       </p>
    1462       <p id="rfc.section.6.2.p.7">Transfer-codings are analogous to the Content-Transfer-Encoding values of MIME, which were designed to enable safe transport
     1444         (<a href="#message.length" title="Message Length">Section&nbsp;2.7.4</a>).
     1445      </p>
     1446      <p id="rfc.section.2.10.2.p.7">Transfer-codings are analogous to the Content-Transfer-Encoding values of MIME, which were designed to enable safe transport
    14631447         of binary data over a 7-bit transport service (<a href="#RFC2045" id="rfc.xref.RFC2045.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies">[RFC2045]</cite></a>, <a href="http://tools.ietf.org/html/rfc2045#section-6">Section 6</a>). However, safe transport has a different focus for an 8bit-clean transfer protocol. In HTTP, the only unsafe characteristic
    1464          of message-bodies is the difficulty in determining the exact body length (<a href="#message.length" title="Message Length">Section&nbsp;3.4</a>), or the desire to encrypt data over a shared transport.
    1465       </p>
    1466       <p id="rfc.section.6.2.p.8">The Internet Assigned Numbers Authority (IANA) acts as a registry for transfer-coding value tokens. Initially, the registry
    1467          contains the following tokens: "chunked" (<a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;6.2.1</a>), "gzip", "compress", and "deflate" (<a href="p3-payload.html#content.codings" title="Content Codings">Section 2.2</a> of <a href="#Part3" id="rfc.xref.Part3.7"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>).
    1468       </p>
    1469       <p id="rfc.section.6.2.p.9">New transfer-coding value tokens <em class="bcp14">SHOULD</em> be registered in the same way as new content-coding value tokens (<a href="p3-payload.html#content.codings" title="Content Codings">Section 2.2</a> of <a href="#Part3" id="rfc.xref.Part3.8"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>).
    1470       </p>
    1471       <p id="rfc.section.6.2.p.10">A server which receives an entity-body with a transfer-coding it does not understand <em class="bcp14">SHOULD</em> return 501 (Not Implemented), and close the connection. A server <em class="bcp14">MUST NOT</em> send transfer-codings to an HTTP/1.0 client.
    1472       </p>
    1473       <h3 id="rfc.section.6.2.1"><a href="#rfc.section.6.2.1">6.2.1</a>&nbsp;<a id="chunked.transfer.encoding" href="#chunked.transfer.encoding">Chunked Transfer Coding</a></h3>
    1474       <p id="rfc.section.6.2.1.p.1">The chunked encoding modifies the body of a message in order to transfer it as a series of chunks, each with its own size
     1448         of message-bodies is the difficulty in determining the exact body length (<a href="#message.length" title="Message Length">Section&nbsp;2.7.4</a>), or the desire to encrypt data over a shared transport.
     1449      </p>
     1450      <p id="rfc.section.2.10.2.p.8">The Internet Assigned Numbers Authority (IANA) acts as a registry for transfer-coding value tokens. Initially, the registry
     1451         contains the following tokens: "chunked" (<a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;2.10.2.1</a>), "gzip", "compress", and "deflate" (<a href="p3-payload.html#content.codings" title="Content Codings">Section 2.2</a> of <a href="#Part3" id="rfc.xref.Part3.7"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>).
     1452      </p>
     1453      <p id="rfc.section.2.10.2.p.9">New transfer-coding value tokens <em class="bcp14">SHOULD</em> be registered in the same way as new content-coding value tokens (<a href="p3-payload.html#content.codings" title="Content Codings">Section 2.2</a> of <a href="#Part3" id="rfc.xref.Part3.8"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>).
     1454      </p>
     1455      <p id="rfc.section.2.10.2.p.10">A server which receives an entity-body with a transfer-coding it does not understand <em class="bcp14">SHOULD</em> return 501 (Not Implemented), and close the connection. A server <em class="bcp14">MUST NOT</em> send transfer-codings to an HTTP/1.0 client.
     1456      </p>
     1457      <h4 id="rfc.section.2.10.2.1"><a href="#rfc.section.2.10.2.1">2.10.2.1</a>&nbsp;<a id="chunked.transfer.encoding" href="#chunked.transfer.encoding">Chunked Transfer Coding</a></h4>
     1458      <p id="rfc.section.2.10.2.1.p.1">The chunked encoding modifies the body of a message in order to transfer it as a series of chunks, each with its own size
    14751459         indicator, followed by an <em class="bcp14">OPTIONAL</em> trailer containing entity-header fields. This allows dynamically produced content to be transferred along with the information
    14761460         necessary for the recipient to verify that it has received the full message.
     
    14921476  <a href="#chunked.transfer.encoding" class="smpl">chunk-data</a>     = 1*<a href="#core.rules" class="smpl">OCTET</a> ; a sequence of chunk-size octets
    14931477  <a href="#chunked.transfer.encoding" class="smpl">trailer-part</a>   = *( <a href="#abnf.dependencies" class="smpl">entity-header</a> <a href="#core.rules" class="smpl">CRLF</a> )
    1494 </pre><p id="rfc.section.6.2.1.p.3">The chunk-size field is a string of hex digits indicating the size of the chunk-data in octets. The chunked encoding is ended
     1478</pre><p id="rfc.section.2.10.2.1.p.3">The chunk-size field is a string of hex digits indicating the size of the chunk-data in octets. The chunked encoding is ended
    14951479         by any chunk whose size is zero, followed by the trailer, which is terminated by an empty line.
    14961480      </p>
    1497       <p id="rfc.section.6.2.1.p.4">The trailer allows the sender to include additional HTTP header fields at the end of the message. The Trailer header field
    1498          can be used to indicate which header fields are included in a trailer (see <a href="#header.trailer" id="rfc.xref.header.trailer.2" title="Trailer">Section&nbsp;8.6</a>).
    1499       </p>
    1500       <p id="rfc.section.6.2.1.p.5">A server using chunked transfer-coding in a response <em class="bcp14">MUST NOT</em> use the trailer for any header fields unless at least one of the following is true:
     1481      <p id="rfc.section.2.10.2.1.p.4">The trailer allows the sender to include additional HTTP header fields at the end of the message. The Trailer header field
     1482         can be used to indicate which header fields are included in a trailer (see <a href="#header.trailer" id="rfc.xref.header.trailer.2" title="Trailer">Section&nbsp;3.6</a>).
     1483      </p>
     1484      <p id="rfc.section.2.10.2.1.p.5">A server using chunked transfer-coding in a response <em class="bcp14">MUST NOT</em> use the trailer for any header fields unless at least one of the following is true:
    15011485      </p>
    15021486      <ol>
    15031487         <li>the request included a TE header field that indicates "trailers" is acceptable in the transfer-coding of the response, as
    1504             described in <a href="#header.te" id="rfc.xref.header.te.2" title="TE">Section&nbsp;8.5</a>; or,
     1488            described in <a href="#header.te" id="rfc.xref.header.te.2" title="TE">Section&nbsp;3.5</a>; or,
    15051489         </li>
    15061490         <li>the server is the origin server for the response, the trailer fields consist entirely of optional metadata, and the recipient
     
    15091493         </li>
    15101494      </ol>
    1511       <p id="rfc.section.6.2.1.p.6">This requirement prevents an interoperability failure when the message is being received by an HTTP/1.1 (or later) proxy and
     1495      <p id="rfc.section.2.10.2.1.p.6">This requirement prevents an interoperability failure when the message is being received by an HTTP/1.1 (or later) proxy and
    15121496         forwarded to an HTTP/1.0 recipient. It avoids a situation where compliance with the protocol would have necessitated a possibly
    15131497         infinite buffer on the proxy.
    15141498      </p>
    1515       <p id="rfc.section.6.2.1.p.7">A process for decoding the "chunked" transfer-coding can be represented in pseudo-code as:</p>
     1499      <p id="rfc.section.2.10.2.1.p.7">A process for decoding the "chunked" transfer-coding can be represented in pseudo-code as:</p>
    15161500      <div id="rfc.figure.u.48"></div><pre class="text">  length := 0
    15171501  read chunk-size, chunk-ext (if any) and CRLF
     
    15291513  Content-Length := length
    15301514  Remove "chunked" from Transfer-Encoding
    1531 </pre><p id="rfc.section.6.2.1.p.9">All HTTP/1.1 applications <em class="bcp14">MUST</em> be able to receive and decode the "chunked" transfer-coding, and <em class="bcp14">MUST</em> ignore chunk-ext extensions they do not understand.
    1532       </p>
    1533       <h2 id="rfc.section.6.3"><a href="#rfc.section.6.3">6.3</a>&nbsp;<a id="product.tokens" href="#product.tokens">Product Tokens</a></h2>
    1534       <p id="rfc.section.6.3.p.1">Product tokens are used to allow communicating applications to identify themselves by software name and version. Most fields
     1515</pre><p id="rfc.section.2.10.2.1.p.9">All HTTP/1.1 applications <em class="bcp14">MUST</em> be able to receive and decode the "chunked" transfer-coding, and <em class="bcp14">MUST</em> ignore chunk-ext extensions they do not understand.
     1516      </p>
     1517      <h3 id="rfc.section.2.10.3"><a href="#rfc.section.2.10.3">2.10.3</a>&nbsp;<a id="product.tokens" href="#product.tokens">Product Tokens</a></h3>
     1518      <p id="rfc.section.2.10.3.p.1">Product tokens are used to allow communicating applications to identify themselves by software name and version. Most fields
    15351519         using product tokens also allow sub-products which form a significant part of the application to be listed, separated by whitespace.
    15361520         By convention, the products are listed in order of their significance for identifying the application.
     
    15381522      <div id="rfc.figure.u.49"></div><pre class="inline"><span id="rfc.iref.g.86"></span><span id="rfc.iref.g.87"></span>  <a href="#product.tokens" class="smpl">product</a>         = <a href="#rule.token.separators" class="smpl">token</a> ["/" <a href="#product.tokens" class="smpl">product-version</a>]
    15391523  <a href="#product.tokens" class="smpl">product-version</a> = <a href="#rule.token.separators" class="smpl">token</a>
    1540 </pre><p id="rfc.section.6.3.p.3">Examples:</p>
     1524</pre><p id="rfc.section.2.10.3.p.3">Examples:</p>
    15411525      <div id="rfc.figure.u.50"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
    15421526  Server: Apache/0.8.4
    1543 </pre><p id="rfc.section.6.3.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 character <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).
    1544       </p>
    1545       <h2 id="rfc.section.6.4"><a href="#rfc.section.6.4">6.4</a>&nbsp;<a id="quality.values" href="#quality.values">Quality Values</a></h2>
    1546       <p id="rfc.section.6.4.p.1">Both transfer codings (TE request header, <a href="#header.te" id="rfc.xref.header.te.3" title="TE">Section&nbsp;8.5</a>) and content negotiation (<a href="p3-payload.html#content.negotiation" title="Content Negotiation">Section 4</a> of <a href="#Part3" id="rfc.xref.Part3.9"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>) use short "floating point" numbers to indicate the relative importance ("weight") of various negotiable parameters. A weight
     1527</pre><p id="rfc.section.2.10.3.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 character <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).
     1528      </p>
     1529      <h3 id="rfc.section.2.10.4"><a href="#rfc.section.2.10.4">2.10.4</a>&nbsp;<a id="quality.values" href="#quality.values">Quality Values</a></h3>
     1530      <p id="rfc.section.2.10.4.p.1">Both transfer codings (TE request header, <a href="#header.te" id="rfc.xref.header.te.3" title="TE">Section&nbsp;3.5</a>) and content negotiation (<a href="p3-payload.html#content.negotiation" title="Content Negotiation">Section 4</a> of <a href="#Part3" id="rfc.xref.Part3.9"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>) use short "floating point" numbers to indicate the relative importance ("weight") of various negotiable parameters. A weight
    15471531         is normalized to a real number in the range 0 through 1, where 0 is the minimum and 1 the maximum value. If a parameter has
    15481532         a quality value of 0, then content with this parameter is `not acceptable' for the client. HTTP/1.1 applications <em class="bcp14">MUST NOT</em> generate more than three digits after the decimal point. User configuration of these values <em class="bcp14">SHOULD</em> also be limited in this fashion.
     
    15541538         </p>
    15551539      </div>
    1556       <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a id="connections" href="#connections">Connections</a></h1>
    1557       <h2 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1</a>&nbsp;<a id="persistent.connections" href="#persistent.connections">Persistent Connections</a></h2>
    1558       <h3 id="rfc.section.7.1.1"><a href="#rfc.section.7.1.1">7.1.1</a>&nbsp;<a id="persistent.purpose" href="#persistent.purpose">Purpose</a></h3>
    1559       <p id="rfc.section.7.1.1.p.1">Prior to persistent connections, a separate TCP connection was established to fetch each URL, increasing the load on HTTP
     1540      <h2 id="rfc.section.2.11"><a href="#rfc.section.2.11">2.11</a>&nbsp;<a id="connections" href="#connections">Connections</a></h2>
     1541      <h3 id="rfc.section.2.11.1"><a href="#rfc.section.2.11.1">2.11.1</a>&nbsp;<a id="persistent.connections" href="#persistent.connections">Persistent Connections</a></h3>
     1542      <h4 id="rfc.section.2.11.1.1"><a href="#rfc.section.2.11.1.1">2.11.1.1</a>&nbsp;<a id="persistent.purpose" href="#persistent.purpose">Purpose</a></h4>
     1543      <p id="rfc.section.2.11.1.1.p.1">Prior to persistent connections, a separate TCP connection was established to fetch each URL, increasing the load on HTTP
    15601544         servers and causing congestion on the Internet. The use of inline images and other associated data often require a client
    15611545         to make multiple requests of the same server in a short amount of time. Analysis of these performance problems and results
    15621546         from a prototype implementation are available <a href="#Pad1995" id="rfc.xref.Pad1995.1"><cite title="Improving HTTP Latency">[Pad1995]</cite></a>  <a href="#Spe" id="rfc.xref.Spe.1"><cite title="Analysis of HTTP Performance Problems">[Spe]</cite></a>. Implementation experience and measurements of actual HTTP/1.1 implementations show good results <a href="#Nie1997" id="rfc.xref.Nie1997.1"><cite title="Network Performance Effects of HTTP/1.1, CSS1, and PNG">[Nie1997]</cite></a>. Alternatives have also been explored, for example, T/TCP <a href="#Tou1998" id="rfc.xref.Tou1998.1"><cite title="Analysis of HTTP Performance">[Tou1998]</cite></a>.
    15631547      </p>
    1564       <p id="rfc.section.7.1.1.p.2">Persistent HTTP connections have a number of advantages: </p>
     1548      <p id="rfc.section.2.11.1.1.p.2">Persistent HTTP connections have a number of advantages: </p>
    15651549      <ul>
    15661550         <li>By opening and closing fewer TCP connections, CPU time is saved in routers and hosts (clients, servers, proxies, gateways,
     
    15791563         </li>
    15801564      </ul>
    1581       <p id="rfc.section.7.1.1.p.3">HTTP implementations <em class="bcp14">SHOULD</em> implement persistent connections.
    1582       </p>
    1583       <h3 id="rfc.section.7.1.2"><a href="#rfc.section.7.1.2">7.1.2</a>&nbsp;<a id="persistent.overall" href="#persistent.overall">Overall Operation</a></h3>
    1584       <p id="rfc.section.7.1.2.p.1">A significant difference between HTTP/1.1 and earlier versions of HTTP is that persistent connections are the default behavior
     1565      <p id="rfc.section.2.11.1.1.p.3">HTTP implementations <em class="bcp14">SHOULD</em> implement persistent connections.
     1566      </p>
     1567      <h4 id="rfc.section.2.11.1.2"><a href="#rfc.section.2.11.1.2">2.11.1.2</a>&nbsp;<a id="persistent.overall" href="#persistent.overall">Overall Operation</a></h4>
     1568      <p id="rfc.section.2.11.1.2.p.1">A significant difference between HTTP/1.1 and earlier versions of HTTP is that persistent connections are the default behavior
    15851569         of any HTTP connection. That is, unless otherwise indicated, the client <em class="bcp14">SHOULD</em> assume that the server will maintain a persistent connection, even after error responses from the server.
    15861570      </p>
    1587       <p id="rfc.section.7.1.2.p.2">Persistent connections provide a mechanism by which a client and a server can signal the close of a TCP connection. This signaling
    1588          takes place using the Connection header field (<a href="#header.connection" id="rfc.xref.header.connection.2" title="Connection">Section&nbsp;8.1</a>). Once a close has been signaled, the client <em class="bcp14">MUST NOT</em> send any more requests on that connection.
    1589       </p>
    1590       <h4 id="rfc.section.7.1.2.1"><a href="#rfc.section.7.1.2.1">7.1.2.1</a>&nbsp;<a id="persistent.negotiation" href="#persistent.negotiation">Negotiation</a></h4>
    1591       <p id="rfc.section.7.1.2.1.p.1">An HTTP/1.1 server <em class="bcp14">MAY</em> assume that a HTTP/1.1 client intends to maintain a persistent connection unless a Connection header including the connection-token
     1571      <p id="rfc.section.2.11.1.2.p.2">Persistent connections provide a mechanism by which a client and a server can signal the close of a TCP connection. This signaling
     1572         takes place using the Connection header field (<a href="#header.connection" id="rfc.xref.header.connection.2" title="Connection">Section&nbsp;3.1</a>). Once a close has been signaled, the client <em class="bcp14">MUST NOT</em> send any more requests on that connection.
     1573      </p>
     1574      <h5 id="rfc.section.2.11.1.2.1"><a href="#rfc.section.2.11.1.2.1">2.11.1.2.1</a>&nbsp;<a id="persistent.negotiation" href="#persistent.negotiation">Negotiation</a></h5>
     1575      <p id="rfc.section.2.11.1.2.1.p.1">An HTTP/1.1 server <em class="bcp14">MAY</em> assume that a HTTP/1.1 client intends to maintain a persistent connection unless a Connection header including the connection-token
    15921576         "close" was sent in the request. If the server chooses to close the connection immediately after sending the response, it <em class="bcp14">SHOULD</em> send a Connection header including the connection-token close.
    15931577      </p>
    1594       <p id="rfc.section.7.1.2.1.p.2">An HTTP/1.1 client <em class="bcp14">MAY</em> expect a connection to remain open, but would decide to keep it open based on whether the response from a server contains
     1578      <p id="rfc.section.2.11.1.2.1.p.2">An HTTP/1.1 client <em class="bcp14">MAY</em> expect a connection to remain open, but would decide to keep it open based on whether the response from a server contains
    15951579         a Connection header with the connection-token close. In case the client does not want to maintain a connection for more than
    15961580         that request, it <em class="bcp14">SHOULD</em> send a Connection header including the connection-token close.
    15971581      </p>
    1598       <p id="rfc.section.7.1.2.1.p.3">If either the client or the server sends the close token in the Connection header, that request becomes the last one for the
     1582      <p id="rfc.section.2.11.1.2.1.p.3">If either the client or the server sends the close token in the Connection header, that request becomes the last one for the
    15991583         connection.
    16001584      </p>
    1601       <p id="rfc.section.7.1.2.1.p.4">Clients and servers <em class="bcp14">SHOULD NOT</em> assume that a persistent connection is maintained for HTTP versions less than 1.1 unless it is explicitly signaled. See <a href="#compatibility.with.http.1.0.persistent.connections" title="Compatibility with HTTP/1.0 Persistent Connections">Appendix&nbsp;B.2</a> for more information on backward compatibility with HTTP/1.0 clients.
    1602       </p>
    1603       <p id="rfc.section.7.1.2.1.p.5">In order to remain persistent, all messages on the connection <em class="bcp14">MUST</em> have a self-defined message length (i.e., one not defined by closure of the connection), as described in <a href="#message.length" title="Message Length">Section&nbsp;3.4</a>.
    1604       </p>
    1605       <h4 id="rfc.section.7.1.2.2"><a href="#rfc.section.7.1.2.2">7.1.2.2</a>&nbsp;<a id="pipelining" href="#pipelining">Pipelining</a></h4>
    1606       <p id="rfc.section.7.1.2.2.p.1">A client that supports persistent connections <em class="bcp14">MAY</em> "pipeline" its requests (i.e., send multiple requests without waiting for each response). A server <em class="bcp14">MUST</em> send its responses to those requests in the same order that the requests were received.
    1607       </p>
    1608       <p id="rfc.section.7.1.2.2.p.2">Clients which assume persistent connections and pipeline immediately after connection establishment <em class="bcp14">SHOULD</em> be prepared to retry their connection if the first pipelined attempt fails. If a client does such a retry, it <em class="bcp14">MUST NOT</em> pipeline before it knows the connection is persistent. Clients <em class="bcp14">MUST</em> also be prepared to resend their requests if the server closes the connection before sending all of the corresponding responses.
    1609       </p>
    1610       <p id="rfc.section.7.1.2.2.p.3">Clients <em class="bcp14">SHOULD NOT</em> pipeline requests using non-idempotent methods or non-idempotent sequences of methods (see <a href="p2-semantics.html#idempotent.methods" title="Idempotent Methods">Section 7.1.2</a> of <a href="#Part2" id="rfc.xref.Part2.8"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). Otherwise, a premature termination of the transport connection could lead to indeterminate results. A client wishing to
     1585      <p id="rfc.section.2.11.1.2.1.p.4">Clients and servers <em class="bcp14">SHOULD NOT</em> assume that a persistent connection is maintained for HTTP versions less than 1.1 unless it is explicitly signaled. See <a href="#compatibility.with.http.1.0.persistent.connections" title="Compatibility with HTTP/1.0 Persistent Connections">Appendix&nbsp;B.2</a> for more information on backward compatibility with HTTP/1.0 clients.
     1586      </p>
     1587      <p id="rfc.section.2.11.1.2.1.p.5">In order to remain persistent, all messages on the connection <em class="bcp14">MUST</em> have a self-defined message length (i.e., one not defined by closure of the connection), as described in <a href="#message.length" title="Message Length">Section&nbsp;2.7.4</a>.
     1588      </p>
     1589      <h5 id="rfc.section.2.11.1.2.2"><a href="#rfc.section.2.11.1.2.2">2.11.1.2.2</a>&nbsp;<a id="pipelining" href="#pipelining">Pipelining</a></h5>
     1590      <p id="rfc.section.2.11.1.2.2.p.1">A client that supports persistent connections <em class="bcp14">MAY</em> "pipeline" its requests (i.e., send multiple requests without waiting for each response). A server <em class="bcp14">MUST</em> send its responses to those requests in the same order that the requests were received.
     1591      </p>
     1592      <p id="rfc.section.2.11.1.2.2.p.2">Clients which assume persistent connections and pipeline immediately after connection establishment <em class="bcp14">SHOULD</em> be prepared to retry their connection if the first pipelined attempt fails. If a client does such a retry, it <em class="bcp14">MUST NOT</em> pipeline before it knows the connection is persistent. Clients <em class="bcp14">MUST</em> also be prepared to resend their requests if the server closes the connection before sending all of the corresponding responses.
     1593      </p>
     1594      <p id="rfc.section.2.11.1.2.2.p.3">Clients <em class="bcp14">SHOULD NOT</em> pipeline requests using non-idempotent methods or non-idempotent sequences of methods (see <a href="p2-semantics.html#idempotent.methods" title="Idempotent Methods">Section 7.1.2</a> of <a href="#Part2" id="rfc.xref.Part2.8"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). Otherwise, a premature termination of the transport connection could lead to indeterminate results. A client wishing to
    16111595         send a non-idempotent request <em class="bcp14">SHOULD</em> wait to send that request until it has received the response status for the previous request.
    16121596      </p>
    1613       <h3 id="rfc.section.7.1.3"><a href="#rfc.section.7.1.3">7.1.3</a>&nbsp;<a id="persistent.proxy" href="#persistent.proxy">Proxy Servers</a></h3>
    1614       <p id="rfc.section.7.1.3.p.1">It is especially important that proxies correctly implement the properties of the Connection header field as specified in <a href="#header.connection" id="rfc.xref.header.connection.3" title="Connection">Section&nbsp;8.1</a>.
    1615       </p>
    1616       <p id="rfc.section.7.1.3.p.2">The proxy server <em class="bcp14">MUST</em> signal persistent connections separately with its clients and the origin servers (or other proxy servers) that it connects
     1597      <h4 id="rfc.section.2.11.1.3"><a href="#rfc.section.2.11.1.3">2.11.1.3</a>&nbsp;<a id="persistent.proxy" href="#persistent.proxy">Proxy Servers</a></h4>
     1598      <p id="rfc.section.2.11.1.3.p.1">It is especially important that proxies correctly implement the properties of the Connection header field as specified in <a href="#header.connection" id="rfc.xref.header.connection.3" title="Connection">Section&nbsp;3.1</a>.
     1599      </p>
     1600      <p id="rfc.section.2.11.1.3.p.2">The proxy server <em class="bcp14">MUST</em> signal persistent connections separately with its clients and the origin servers (or other proxy servers) that it connects
    16171601         to. Each persistent connection applies to only one transport link.
    16181602      </p>
    1619       <p id="rfc.section.7.1.3.p.3">A proxy server <em class="bcp14">MUST NOT</em> establish a HTTP/1.1 persistent connection with an HTTP/1.0 client (but see <a href="http://tools.ietf.org/html/rfc2068#section-19.7.1">Section 19.7.1</a> of <a href="#RFC2068" id="rfc.xref.RFC2068.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a> for information and discussion of the problems with the Keep-Alive header implemented by many HTTP/1.0 clients).
    1620       </p>
    1621       <h3 id="rfc.section.7.1.4"><a href="#rfc.section.7.1.4">7.1.4</a>&nbsp;<a id="persistent.practical" href="#persistent.practical">Practical Considerations</a></h3>
    1622       <p id="rfc.section.7.1.4.p.1">Servers will usually have some time-out value beyond which they will no longer maintain an inactive connection. Proxy servers
     1603      <p id="rfc.section.2.11.1.3.p.3">A proxy server <em class="bcp14">MUST NOT</em> establish a HTTP/1.1 persistent connection with an HTTP/1.0 client (but see <a href="http://tools.ietf.org/html/rfc2068#section-19.7.1">Section 19.7.1</a> of <a href="#RFC2068" id="rfc.xref.RFC2068.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a> for information and discussion of the problems with the Keep-Alive header implemented by many HTTP/1.0 clients).
     1604      </p>
     1605      <h4 id="rfc.section.2.11.1.4"><a href="#rfc.section.2.11.1.4">2.11.1.4</a>&nbsp;<a id="persistent.practical" href="#persistent.practical">Practical Considerations</a></h4>
     1606      <p id="rfc.section.2.11.1.4.p.1">Servers will usually have some time-out value beyond which they will no longer maintain an inactive connection. Proxy servers
    16231607         might make this a higher value since it is likely that the client will be making more connections through the same server.
    16241608         The use of persistent connections places no requirements on the length (or existence) of this time-out for either the client
    16251609         or the server.
    16261610      </p>
    1627       <p id="rfc.section.7.1.4.p.2">When a client or server wishes to time-out it <em class="bcp14">SHOULD</em> issue a graceful close on the transport connection. Clients and servers <em class="bcp14">SHOULD</em> both constantly watch for the other side of the transport close, and respond to it as appropriate. If a client or server does
     1611      <p id="rfc.section.2.11.1.4.p.2">When a client or server wishes to time-out it <em class="bcp14">SHOULD</em> issue a graceful close on the transport connection. Clients and servers <em class="bcp14">SHOULD</em> both constantly watch for the other side of the transport close, and respond to it as appropriate. If a client or server does
    16281612         not detect the other side's close promptly it could cause unnecessary resource drain on the network.
    16291613      </p>
    1630       <p id="rfc.section.7.1.4.p.3">A client, server, or proxy <em class="bcp14">MAY</em> close the transport connection at any time. For example, a client might have started to send a new request at the same time
     1614      <p id="rfc.section.2.11.1.4.p.3">A client, server, or proxy <em class="bcp14">MAY</em> close the transport connection at any time. For example, a client might have started to send a new request at the same time
    16311615         that the server has decided to close the "idle" connection. From the server's point of view, the connection is being closed
    16321616         while it was idle, but from the client's point of view, a request is in progress.
    16331617      </p>
    1634       <p id="rfc.section.7.1.4.p.4">This means that clients, servers, and proxies <em class="bcp14">MUST</em> be able to recover from asynchronous close events. Client software <em class="bcp14">SHOULD</em> reopen the transport connection and retransmit the aborted sequence of requests without user interaction so long as the request
     1618      <p id="rfc.section.2.11.1.4.p.4">This means that clients, servers, and proxies <em class="bcp14">MUST</em> be able to recover from asynchronous close events. Client software <em class="bcp14">SHOULD</em> reopen the transport connection and retransmit the aborted sequence of requests without user interaction so long as the request
    16351619         sequence is idempotent (see <a href="p2-semantics.html#idempotent.methods" title="Idempotent Methods">Section 7.1.2</a> of <a href="#Part2" id="rfc.xref.Part2.9"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). Non-idempotent methods or sequences <em class="bcp14">MUST NOT</em> be automatically retried, although user agents <em class="bcp14">MAY</em> offer a human operator the choice of retrying the request(s). Confirmation by user-agent software with semantic understanding
    16361620         of the application <em class="bcp14">MAY</em> substitute for user confirmation. The automatic retry <em class="bcp14">SHOULD NOT</em> be repeated if the second sequence of requests fails.
    16371621      </p>
    1638       <p id="rfc.section.7.1.4.p.5">Servers <em class="bcp14">SHOULD</em> always respond to at least one request per connection, if at all possible. Servers <em class="bcp14">SHOULD NOT</em> close a connection in the middle of transmitting a response, unless a network or client failure is suspected.
    1639       </p>
    1640       <p id="rfc.section.7.1.4.p.6">Clients that use persistent connections <em class="bcp14">SHOULD</em> limit the number of simultaneous connections that they maintain to a given server. A single-user client <em class="bcp14">SHOULD NOT</em> maintain more than 2 connections with any server or proxy. A proxy <em class="bcp14">SHOULD</em> use up to 2*N connections to another server or proxy, where N is the number of simultaneously active users. These guidelines
     1622      <p id="rfc.section.2.11.1.4.p.5">Servers <em class="bcp14">SHOULD</em> always respond to at least one request per connection, if at all possible. Servers <em class="bcp14">SHOULD NOT</em> close a connection in the middle of transmitting a response, unless a network or client failure is suspected.
     1623      </p>
     1624      <p id="rfc.section.2.11.1.4.p.6">Clients that use persistent connections <em class="bcp14">SHOULD</em> limit the number of simultaneous connections that they maintain to a given server. A single-user client <em class="bcp14">SHOULD NOT</em> maintain more than 2 connections with any server or proxy. A proxy <em class="bcp14">SHOULD</em> use up to 2*N connections to another server or proxy, where N is the number of simultaneously active users. These guidelines
    16411625         are intended to improve HTTP response times and avoid congestion.
    16421626      </p>
    1643       <h2 id="rfc.section.7.2"><a href="#rfc.section.7.2">7.2</a>&nbsp;<a id="message.transmission.requirements" href="#message.transmission.requirements">Message Transmission Requirements</a></h2>
    1644       <h3 id="rfc.section.7.2.1"><a href="#rfc.section.7.2.1">7.2.1</a>&nbsp;<a id="persistent.flow" href="#persistent.flow">Persistent Connections and Flow Control</a></h3>
    1645       <p id="rfc.section.7.2.1.p.1">HTTP/1.1 servers <em class="bcp14">SHOULD</em> maintain persistent connections and use TCP's flow control mechanisms to resolve temporary overloads, rather than terminating
     1627      <h3 id="rfc.section.2.11.2"><a href="#rfc.section.2.11.2">2.11.2</a>&nbsp;<a id="message.transmission.requirements" href="#message.transmission.requirements">Message Transmission Requirements</a></h3>
     1628      <h4 id="rfc.section.2.11.2.1"><a href="#rfc.section.2.11.2.1">2.11.2.1</a>&nbsp;<a id="persistent.flow" href="#persistent.flow">Persistent Connections and Flow Control</a></h4>
     1629      <p id="rfc.section.2.11.2.1.p.1">HTTP/1.1 servers <em class="bcp14">SHOULD</em> maintain persistent connections and use TCP's flow control mechanisms to resolve temporary overloads, rather than terminating
    16461630         connections with the expectation that clients will retry. The latter technique can exacerbate network congestion.
    16471631      </p>
    1648       <h3 id="rfc.section.7.2.2"><a href="#rfc.section.7.2.2">7.2.2</a>&nbsp;<a id="persistent.monitor" href="#persistent.monitor">Monitoring Connections for Error Status Messages</a></h3>
    1649       <p id="rfc.section.7.2.2.p.1">An HTTP/1.1 (or later) client sending a message-body <em class="bcp14">SHOULD</em> monitor the network connection for an error status while it is transmitting the request. If the client sees an error status,
    1650          it <em class="bcp14">SHOULD</em> immediately cease transmitting the body. If the body is being sent using a "chunked" encoding (<a href="#transfer.codings" title="Transfer Codings">Section&nbsp;6.2</a>), a zero length chunk and empty trailer <em class="bcp14">MAY</em> be used to prematurely mark the end of the message. If the body was preceded by a Content-Length header, the client <em class="bcp14">MUST</em> close the connection.
    1651       </p>
    1652       <h3 id="rfc.section.7.2.3"><a href="#rfc.section.7.2.3">7.2.3</a>&nbsp;<a id="use.of.the.100.status" href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></h3>
    1653       <p id="rfc.section.7.2.3.p.1">The purpose of the 100 (Continue) status (see <a href="p2-semantics.html#status.100" title="100 Continue">Section 8.1.1</a> of <a href="#Part2" id="rfc.xref.Part2.10"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) is to allow a client that is sending a request message with a request body to determine if the origin server is willing
     1632      <h4 id="rfc.section.2.11.2.2"><a href="#rfc.section.2.11.2.2">2.11.2.2</a>&nbsp;<a id="persistent.monitor" href="#persistent.monitor">Monitoring Connections for Error Status Messages</a></h4>
     1633      <p id="rfc.section.2.11.2.2.p.1">An HTTP/1.1 (or later) client sending a message-body <em class="bcp14">SHOULD</em> monitor the network connection for an error status while it is transmitting the request. If the client sees an error status,
     1634         it <em class="bcp14">SHOULD</em> immediately cease transmitting the body. If the body is being sent using a "chunked" encoding (<a href="#transfer.codings" title="Transfer Codings">Section&nbsp;2.10.2</a>), a zero length chunk and empty trailer <em class="bcp14">MAY</em> be used to prematurely mark the end of the message. If the body was preceded by a Content-Length header, the client <em class="bcp14">MUST</em> close the connection.
     1635      </p>
     1636      <h4 id="rfc.section.2.11.2.3"><a href="#rfc.section.2.11.2.3">2.11.2.3</a>&nbsp;<a id="use.of.the.100.status" href="#use.of.the.100.status">Use of the 100 (Continue) Status</a></h4>
     1637      <p id="rfc.section.2.11.2.3.p.1">The purpose of the 100 (Continue) status (see <a href="p2-semantics.html#status.100" title="100 Continue">Section 8.1.1</a> of <a href="#Part2" id="rfc.xref.Part2.10"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) is to allow a client that is sending a request message with a request body to determine if the origin server is willing
    16541638         to accept the request (based on the request headers) before the client sends the request body. In some cases, it might either
    16551639         be inappropriate or highly inefficient for the client to send the body if the server will reject the message without looking
    16561640         at the body.
    16571641      </p>
    1658       <p id="rfc.section.7.2.3.p.2">Requirements for HTTP/1.1 clients: </p>
     1642      <p id="rfc.section.2.11.2.3.p.2">Requirements for HTTP/1.1 clients: </p>
    16591643      <ul>
    16601644         <li>If a client will wait for a 100 (Continue) response before sending the request body, it <em class="bcp14">MUST</em> send an Expect request-header field (<a href="p2-semantics.html#header.expect" title="Expect">Section 9.2</a> of <a href="#Part2" id="rfc.xref.Part2.11"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) with the "100-continue" expectation.
     
    16631647         </li>
    16641648      </ul>
    1665       <p id="rfc.section.7.2.3.p.3">Because of the presence of older implementations, the protocol allows ambiguous situations in which a client may send "Expect:
     1649      <p id="rfc.section.2.11.2.3.p.3">Because of the presence of older implementations, the protocol allows ambiguous situations in which a client may send "Expect:
    16661650         100-continue" without receiving either a 417 (Expectation Failed) status or a 100 (Continue) status. Therefore, when a client
    16671651         sends this header field to an origin server (possibly via a proxy) from which it has never seen a 100 (Continue) status, the
    16681652         client <em class="bcp14">SHOULD NOT</em> wait for an indefinite period before sending the request body.
    16691653      </p>
    1670       <p id="rfc.section.7.2.3.p.4">Requirements for HTTP/1.1 origin servers: </p>
     1654      <p id="rfc.section.2.11.2.3.p.4">Requirements for HTTP/1.1 origin servers: </p>
    16711655      <ul>
    16721656         <li>Upon receiving a request which includes an Expect request-header field with the "100-continue" expectation, an origin server <em class="bcp14">MUST</em> either respond with 100 (Continue) status and continue to read from the input stream, or respond with a final status code.
     
    16921676         </li>
    16931677      </ul>
    1694       <p id="rfc.section.7.2.3.p.5">Requirements for HTTP/1.1 proxies: </p>
     1678      <p id="rfc.section.2.11.2.3.p.5">Requirements for HTTP/1.1 proxies: </p>
    16951679      <ul>
    16961680         <li>If a proxy receives a request that includes an Expect request-header field with the "100-continue" expectation, and the proxy
     
    17071691         </li>
    17081692      </ul>
    1709       <h3 id="rfc.section.7.2.4"><a href="#rfc.section.7.2.4">7.2.4</a>&nbsp;<a id="connection.premature" href="#connection.premature">Client Behavior if Server Prematurely Closes Connection</a></h3>
    1710       <p id="rfc.section.7.2.4.p.1">If an HTTP/1.1 client sends a request which includes a request body, but which does not include an Expect request-header field
     1693      <h4 id="rfc.section.2.11.2.4"><a href="#rfc.section.2.11.2.4">2.11.2.4</a>&nbsp;<a id="connection.premature" href="#connection.premature">Client Behavior if Server Prematurely Closes Connection</a></h4>
     1694      <p id="rfc.section.2.11.2.4.p.1">If an HTTP/1.1 client sends a request which includes a request body, but which does not include an Expect request-header field
    17111695         with the "100-continue" expectation, and if the client is not directly connected to an HTTP/1.1 origin server, and if the
    17121696         client sees the connection close before receiving any status from the server, the client <em class="bcp14">SHOULD</em> retry the request. If the client does retry this request, it <em class="bcp14">MAY</em> use the following "binary exponential backoff" algorithm to be assured of obtaining a reliable response:
     
    17251709         </li>
    17261710      </ol>
    1727       <p id="rfc.section.7.2.4.p.2">If at any point an error status is received, the client </p>
     1711      <p id="rfc.section.2.11.2.4.p.2">If at any point an error status is received, the client </p>
    17281712      <ul>
    17291713         <li><em class="bcp14">SHOULD NOT</em> continue and
     
    17321716         </li>
    17331717      </ul>
    1734       <h1 id="rfc.section.8"><a href="#rfc.section.8">8.</a>&nbsp;<a id="header.field.definitions" href="#header.field.definitions">Header Field Definitions</a></h1>
    1735       <p id="rfc.section.8.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to message framing and transport protocols.</p>
    1736       <p id="rfc.section.8.p.2">For entity-header fields, both sender and recipient refer to either the client or the server, depending on who sends and who
     1718      <h2 id="rfc.section.2.12"><a href="#rfc.section.2.12">2.12</a>&nbsp;<a id="misc" href="#misc">Miscellaneous notes that may disappear</a></h2>
     1719      <h3 id="rfc.section.2.12.1"><a href="#rfc.section.2.12.1">2.12.1</a>&nbsp;<a id="scheme.aliases" href="#scheme.aliases">Scheme aliases considered harmful</a></h3>
     1720      <p id="rfc.section.2.12.1.p.1"> <span class="comment" id="rfc.comment.2">[<a href="#rfc.comment.2" class="smpl">rfc.comment.2</a>: TBS: describe why aliases like webcal are harmful.]</span>
     1721      </p>
     1722      <h2 id="rfc.section.2.13"><a href="#rfc.section.2.13">2.13</a>&nbsp;<a id="http.proxy" href="#http.proxy">Use of HTTP for proxy communication</a></h2>
     1723      <p id="rfc.section.2.13.p.1"> <span class="comment" id="rfc.comment.3">[<a href="#rfc.comment.3" class="smpl">rfc.comment.3</a>: TBD: Configured to use HTTP to proxy HTTP or other protocols.]</span>
     1724      </p>
     1725      <h2 id="rfc.section.2.14"><a href="#rfc.section.2.14">2.14</a>&nbsp;<a id="http.intercept" href="#http.intercept">Interception of HTTP for access control</a></h2>
     1726      <p id="rfc.section.2.14.p.1"> <span class="comment" id="rfc.comment.4">[<a href="#rfc.comment.4" class="smpl">rfc.comment.4</a>: TBD: Interception of HTTP traffic for initiating access control.]</span>
     1727      </p>
     1728      <h2 id="rfc.section.2.15"><a href="#rfc.section.2.15">2.15</a>&nbsp;<a id="http.others" href="#http.others">Use of HTTP by other protocols</a></h2>
     1729      <p id="rfc.section.2.15.p.1"> <span class="comment" id="rfc.comment.5">[<a href="#rfc.comment.5" class="smpl">rfc.comment.5</a>: TBD: Profiles of HTTP defined by other protocol. Extensions of HTTP like WebDAV.]</span>
     1730      </p>
     1731      <h2 id="rfc.section.2.16"><a href="#rfc.section.2.16">2.16</a>&nbsp;<a id="http.media" href="#http.media">Use of HTTP by media type specification</a></h2>
     1732      <p id="rfc.section.2.16.p.1"> <span class="comment" id="rfc.comment.6">[<a href="#rfc.comment.6" class="smpl">rfc.comment.6</a>: TBD: Instructions on composing HTTP requests via hypertext formats.]</span>
     1733      </p>
     1734      <h1 id="rfc.section.3"><a href="#rfc.section.3">3.</a>&nbsp;<a id="header.field.definitions" href="#header.field.definitions">Header Field Definitions</a></h1>
     1735      <p id="rfc.section.3.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to message framing and transport protocols.</p>
     1736      <p id="rfc.section.3.p.2">For entity-header fields, both sender and recipient refer to either the client or the server, depending on who sends and who
    17371737         receives the entity.
    17381738      </p>
    17391739      <div id="rfc.iref.c.5"></div>
    17401740      <div id="rfc.iref.h.6"></div>
    1741       <h2 id="rfc.section.8.1"><a href="#rfc.section.8.1">8.1</a>&nbsp;<a id="header.connection" href="#header.connection">Connection</a></h2>
    1742       <p id="rfc.section.8.1.p.1">The general-header field "Connection" allows the sender to specify options that are desired for that particular connection
     1741      <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a id="header.connection" href="#header.connection">Connection</a></h2>
     1742      <p id="rfc.section.3.1.p.1">The general-header field "Connection" allows the sender to specify options that are desired for that particular connection
    17431743         and <em class="bcp14">MUST NOT</em> be communicated by proxies over further connections.
    17441744      </p>
    1745       <p id="rfc.section.8.1.p.2">The Connection header's value has the following grammar:</p>
     1745      <p id="rfc.section.3.1.p.2">The Connection header's value has the following grammar:</p>
    17461746      <div id="rfc.figure.u.52"></div><pre class="inline"><span id="rfc.iref.g.89"></span><span id="rfc.iref.g.90"></span><span id="rfc.iref.g.91"></span>  <a href="#header.connection" class="smpl">Connection</a>       = "Connection" ":" <a href="#rule.whitespace" class="smpl">OWS</a> <a href="#header.connection" class="smpl">Connection-v</a>
    17471747  <a href="#header.connection" class="smpl">Connection-v</a>     = 1#<a href="#header.connection" class="smpl">connection-token</a>
    17481748  <a href="#header.connection" class="smpl">connection-token</a> = <a href="#rule.token.separators" class="smpl">token</a>
    1749 </pre><p id="rfc.section.8.1.p.4">HTTP/1.1 proxies <em class="bcp14">MUST</em> parse the Connection header field before a message is forwarded and, for each connection-token in this field, remove any header
     1749</pre><p id="rfc.section.3.1.p.4">HTTP/1.1 proxies <em class="bcp14">MUST</em> parse the Connection header field before a message is forwarded and, for each connection-token in this field, remove any header
    17501750         field(s) from the message with the same name as the connection-token. Connection options are signaled by the presence of a
    17511751         connection-token in the Connection header field, not by any corresponding additional header field(s), since the additional
    17521752         header field may not be sent if there are no parameters associated with that connection option.
    17531753      </p>
    1754       <p id="rfc.section.8.1.p.5">Message headers listed in the Connection header <em class="bcp14">MUST NOT</em> include end-to-end headers, such as Cache-Control.
    1755       </p>
    1756       <p id="rfc.section.8.1.p.6">HTTP/1.1 defines the "close" connection option for the sender to signal that the connection will be closed after completion
     1754      <p id="rfc.section.3.1.p.5">Message headers listed in the Connection header <em class="bcp14">MUST NOT</em> include end-to-end headers, such as Cache-Control.
     1755      </p>
     1756      <p id="rfc.section.3.1.p.6">HTTP/1.1 defines the "close" connection option for the sender to signal that the connection will be closed after completion
    17571757         of the response. For example,
    17581758      </p>
    17591759      <div id="rfc.figure.u.53"></div><pre class="text">  Connection: close
    1760 </pre><p id="rfc.section.8.1.p.8">in either the request or the response header fields indicates that the connection <em class="bcp14">SHOULD NOT</em> be considered `persistent' (<a href="#persistent.connections" title="Persistent Connections">Section&nbsp;7.1</a>) after the current request/response is complete.
    1761       </p>
    1762       <p id="rfc.section.8.1.p.9">An HTTP/1.1 client that does not support persistent connections <em class="bcp14">MUST</em> include the "close" connection option in every request message.
    1763       </p>
    1764       <p id="rfc.section.8.1.p.10">An HTTP/1.1 server that does not support persistent connections <em class="bcp14">MUST</em> include the "close" connection option in every response message that does not have a 1xx (informational) status code.
    1765       </p>
    1766       <p id="rfc.section.8.1.p.11">A system receiving an HTTP/1.0 (or lower-version) message that includes a Connection header <em class="bcp14">MUST</em>, for each connection-token in this field, remove and ignore any header field(s) from the message with the same name as the
     1760</pre><p id="rfc.section.3.1.p.8">in either the request or the response header fields indicates that the connection <em class="bcp14">SHOULD NOT</em> be considered `persistent' (<a href="#persistent.connections" title="Persistent Connections">Section&nbsp;2.11.1</a>) after the current request/response is complete.
     1761      </p>
     1762      <p id="rfc.section.3.1.p.9">An HTTP/1.1 client that does not support persistent connections <em class="bcp14">MUST</em> include the "close" connection option in every request message.
     1763      </p>
     1764      <p id="rfc.section.3.1.p.10">An HTTP/1.1 server that does not support persistent connections <em class="bcp14">MUST</em> include the "close" connection option in every response message that does not have a 1xx (informational) status code.
     1765      </p>
     1766      <p id="rfc.section.3.1.p.11">A system receiving an HTTP/1.0 (or lower-version) message that includes a Connection header <em class="bcp14">MUST</em>, for each connection-token in this field, remove and ignore any header field(s) from the message with the same name as the
    17671767         connection-token. This protects against mistaken forwarding of such header fields by pre-HTTP/1.1 proxies. See <a href="#compatibility.with.http.1.0.persistent.connections" title="Compatibility with HTTP/1.0 Persistent Connections">Appendix&nbsp;B.2</a>.
    17681768      </p>
    17691769      <div id="rfc.iref.c.6"></div>
    17701770      <div id="rfc.iref.h.7"></div>
    1771       <h2 id="rfc.section.8.2"><a href="#rfc.section.8.2">8.2</a>&nbsp;<a id="header.content-length" href="#header.content-length">Content-Length</a></h2>
    1772       <p id="rfc.section.8.2.p.1">The entity-header field "Content-Length" indicates the size of the entity-body, in number of OCTETs, sent to the recipient
     1771      <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a>&nbsp;<a id="header.content-length" href="#header.content-length">Content-Length</a></h2>
     1772      <p id="rfc.section.3.2.p.1">The entity-header field "Content-Length" indicates the size of the entity-body, in number of OCTETs, sent to the recipient
    17731773         or, in the case of the HEAD method, the size of the entity-body that would have been sent had the request been a GET.
    17741774      </p>
    17751775      <div id="rfc.figure.u.54"></div><pre class="inline"><span id="rfc.iref.g.92"></span><span id="rfc.iref.g.93"></span>  <a href="#header.content-length" class="smpl">Content-Length</a>   = "Content-Length" ":" <a href="#rule.whitespace" class="smpl">OWS</a> 1*<a href="#header.content-length" class="smpl">Content-Length-v</a>
    17761776  <a href="#header.content-length" class="smpl">Content-Length-v</a> = 1*<a href="#core.rules" class="smpl">DIGIT</a>
    1777 </pre><p id="rfc.section.8.2.p.3">An example is</p>
     1777</pre><p id="rfc.section.3.2.p.3">An example is</p>
    17781778      <div id="rfc.figure.u.55"></div><pre class="text">  Content-Length: 3495
    1779 </pre><p id="rfc.section.8.2.p.5">Applications <em class="bcp14">SHOULD</em> use this field to indicate the transfer-length of the message-body, unless this is prohibited by the rules in <a href="#message.length" title="Message Length">Section&nbsp;3.4</a>.
    1780       </p>
    1781       <p id="rfc.section.8.2.p.6">Any Content-Length greater than or equal to zero is a valid value. <a href="#message.length" title="Message Length">Section&nbsp;3.4</a> describes how to determine the length of a message-body if a Content-Length is not given.
    1782       </p>
    1783       <p id="rfc.section.8.2.p.7">Note that the meaning of this field is significantly different from the corresponding definition in MIME, where it is an optional
     1779</pre><p id="rfc.section.3.2.p.5">Applications <em class="bcp14">SHOULD</em> use this field to indicate the transfer-length of the message-body, unless this is prohibited by the rules in <a href="#message.length" title="Message Length">Section&nbsp;2.7.4</a>.
     1780      </p>
     1781      <p id="rfc.section.3.2.p.6">Any Content-Length greater than or equal to zero is a valid value. <a href="#message.length" title="Message Length">Section&nbsp;2.7.4</a> describes how to determine the length of a message-body if a Content-Length is not given.
     1782      </p>
     1783      <p id="rfc.section.3.2.p.7">Note that the meaning of this field is significantly different from the corresponding definition in MIME, where it is an optional
    17841784         field used within the "message/external-body" content-type. In HTTP, it <em class="bcp14">SHOULD</em> be sent whenever the message's length can be determined prior to being transferred, unless this is prohibited by the rules
    1785          in <a href="#message.length" title="Message Length">Section&nbsp;3.4</a>.
     1785         in <a href="#message.length" title="Message Length">Section&nbsp;2.7.4</a>.
    17861786      </p>
    17871787      <div id="rfc.iref.d.2"></div>
    17881788      <div id="rfc.iref.h.8"></div>
    1789       <h2 id="rfc.section.8.3"><a href="#rfc.section.8.3">8.3</a>&nbsp;<a id="header.date" href="#header.date">Date</a></h2>
    1790       <p id="rfc.section.8.3.p.1">The general-header field "Date" represents the date and time at which the message was originated, having the same semantics
    1791          as orig-date 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 described in <a href="#date.time.formats.full.date" title="Date/Time Formats: Full Date">Section&nbsp;6.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.
     1789      <h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="header.date" href="#header.date">Date</a></h2>
     1790      <p id="rfc.section.3.3.p.1">The general-header field "Date" represents the date and time at which the message was originated, having the same semantics
     1791         as orig-date 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 described in <a href="#date.time.formats.full.date" title="Date/Time Formats: Full Date">Section&nbsp;2.10.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.
    17921792      </p>
    17931793      <div id="rfc.figure.u.56"></div><pre class="inline"><span id="rfc.iref.g.94"></span><span id="rfc.iref.g.95"></span>  <a href="#header.date" class="smpl">Date</a>   = "Date" ":" <a href="#rule.whitespace" class="smpl">OWS</a> <a href="#header.date" class="smpl">Date-v</a>
    17941794  <a href="#header.date" class="smpl">Date-v</a> = <a href="#date.time.formats.full.date" class="smpl">HTTP-date</a>
    1795 </pre><p id="rfc.section.8.3.p.3">An example is</p>
     1795</pre><p id="rfc.section.3.3.p.3">An example is</p>
    17961796      <div id="rfc.figure.u.57"></div><pre class="text">  Date: Tue, 15 Nov 1994 08:12:31 GMT
    1797 </pre><p id="rfc.section.8.3.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:
     1797</pre><p id="rfc.section.3.3.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:
    17981798      </p>
    17991799      <ol>
     
    18031803            is inconvenient or impossible to generate a valid Date.
    18041804         </li>
    1805          <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. In this case, the rules in <a href="#clockless.origin.server.operation" title="Clockless Origin Server Operation">Section&nbsp;8.3.1</a>  <em class="bcp14">MUST</em> be followed.
     1805         <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. In this case, the rules in <a href="#clockless.origin.server.operation" title="Clockless Origin Server Operation">Section&nbsp;3.3.1</a>  <em class="bcp14">MUST</em> be followed.
    18061806         </li>
    18071807      </ol>
    1808       <p id="rfc.section.8.3.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 or gatewayed via a protocol which requires
     1808      <p id="rfc.section.3.3.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 or gatewayed via a protocol which requires
    18091809         a Date. An HTTP implementation without a clock <em class="bcp14">MUST NOT</em> cache responses without revalidating them on every use. An HTTP cache, especially a shared cache, <em class="bcp14">SHOULD</em> use a mechanism, such as NTP <a href="#RFC1305" id="rfc.xref.RFC1305.1"><cite title="Network Time Protocol (Version 3) Specification, Implementation">[RFC1305]</cite></a>, to synchronize its clock with a reliable external standard.
    18101810      </p>
    1811       <p id="rfc.section.8.3.p.7">Clients <em class="bcp14">SHOULD</em> only send a Date header field in messages that include an entity-body, as in the case of the PUT and POST requests, and even
     1811      <p id="rfc.section.3.3.p.7">Clients <em class="bcp14">SHOULD</em> only send a Date header field in messages that include an entity-body, as in the case of the PUT and POST requests, and even
    18121812         then it is optional. A client without a clock <em class="bcp14">MUST NOT</em> send a Date header field in a request.
    18131813      </p>
    1814       <p id="rfc.section.8.3.p.8">The HTTP-date sent in a Date header <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
     1814      <p id="rfc.section.3.3.p.8">The HTTP-date sent in a Date header <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
    18151815         of generating a reasonably accurate date and time. In theory, the date ought to represent the moment just before the entity
    18161816         is generated. In practice, the date can be generated at any time during the message origination without affecting its semantic
    18171817         value.
    18181818      </p>
    1819       <h3 id="rfc.section.8.3.1"><a href="#rfc.section.8.3.1">8.3.1</a>&nbsp;<a id="clockless.origin.server.operation" href="#clockless.origin.server.operation">Clockless Origin Server Operation</a></h3>
    1820       <p id="rfc.section.8.3.1.p.1">Some origin server implementations might not have a clock available. An origin server without a clock <em class="bcp14">MUST NOT</em> assign Expires or Last-Modified values to a response, unless these values were associated with the resource by a system or
     1819      <h3 id="rfc.section.3.3.1"><a href="#rfc.section.3.3.1">3.3.1</a>&nbsp;<a id="clockless.origin.server.operation" href="#clockless.origin.server.operation">Clockless Origin Server Operation</a></h3>
     1820      <p id="rfc.section.3.3.1.p.1">Some origin server implementations might not have a clock available. An origin server without a clock <em class="bcp14">MUST NOT</em> assign Expires or Last-Modified values to a response, unless these values were associated with the resource by a system or
    18211821         user with a reliable clock. It <em class="bcp14">MAY</em> assign an Expires value that is known, at or before server configuration time, to be in the past (this allows "pre-expiration"
    18221822         of responses without storing separate Expires values for each resource).
     
    18241824      <div id="rfc.iref.h.9"></div>
    18251825      <div id="rfc.iref.h.10"></div>
    1826       <h2 id="rfc.section.8.4"><a href="#rfc.section.8.4">8.4</a>&nbsp;<a id="header.host" href="#header.host">Host</a></h2>
    1827       <p id="rfc.section.8.4.p.1">The request-header field "Host" specifies the Internet host and port number of the resource being requested, as obtained from
     1826      <h2 id="rfc.section.3.4"><a href="#rfc.section.3.4">3.4</a>&nbsp;<a id="header.host" href="#header.host">Host</a></h2>
     1827      <p id="rfc.section.3.4.p.1">The request-header field "Host" specifies the Internet host and port number of the resource being requested, as obtained from
    18281828         the original URI given by the user or referring resource (generally an http URI, as described in <a href="#http.uri" title="http URI scheme">Section&nbsp;2.6.1</a>). The Host field value <em class="bcp14">MUST</em> represent the naming authority of the origin server or gateway given by the original URL. This allows the origin server or
    18291829         gateway to differentiate between internally-ambiguous URLs, such as the root "/" URL of a server for multiple host names on
     
    18321832      <div id="rfc.figure.u.58"></div><pre class="inline"><span id="rfc.iref.g.96"></span><span id="rfc.iref.g.97"></span>  <a href="#header.host" class="smpl">Host</a>   = "Host" ":" <a href="#rule.whitespace" class="smpl">OWS</a> <a href="#header.host" class="smpl">Host-v</a>
    18331833  <a href="#header.host" class="smpl">Host-v</a> = <a href="#uri" class="smpl">uri-host</a> [ ":" <a href="#uri" class="smpl">port</a> ] ; <a href="#http.uri" title="http URI scheme">Section&nbsp;2.6.1</a>
    1834 </pre><p id="rfc.section.8.4.p.3">A "host" without any trailing port information implies the default port for the service requested (e.g., "80" for an HTTP
     1834</pre><p id="rfc.section.3.4.p.3">A "host" without any trailing port information implies the default port for the service requested (e.g., "80" for an HTTP
    18351835         URL). For example, a request on the origin server for &lt;http://www.example.org/pub/WWW/&gt; would properly include:
    18361836      </p>
    18371837      <div id="rfc.figure.u.59"></div><pre class="text">  GET /pub/WWW/ HTTP/1.1
    18381838  Host: www.example.org
    1839 </pre><p id="rfc.section.8.4.p.5">A client <em class="bcp14">MUST</em> include a Host header field in all HTTP/1.1 request messages. If the requested URI does not include an Internet host name
     1839</pre><p id="rfc.section.3.4.p.5">A client <em class="bcp14">MUST</em> include a Host header field in all HTTP/1.1 request messages. If the requested URI does not include an Internet host name
    18401840         for the service being requested, then the Host header field <em class="bcp14">MUST</em> be given with an empty value. An HTTP/1.1 proxy <em class="bcp14">MUST</em> ensure that any request message it forwards does contain an appropriate Host header field that identifies the service being
    18411841         requested by the proxy. All Internet-based HTTP/1.1 servers <em class="bcp14">MUST</em> respond with a 400 (Bad Request) status code to any HTTP/1.1 request message which lacks a Host header field.
    18421842      </p>
    1843       <p id="rfc.section.8.4.p.6">See Sections <a href="#the.resource.identified.by.a.request" title="The Resource Identified by a Request">4.2</a> and <a href="#changes.to.simplify.multi-homed.web.servers.and.conserve.ip.addresses" title="Changes to Simplify Multi-homed Web Servers and Conserve IP Addresses">B.1.1</a> for other requirements relating to Host.
     1843      <p id="rfc.section.3.4.p.6">See Sections <a href="#the.resource.identified.by.a.request" title="The Resource Identified by a Request">2.8.2</a> and <a href="#changes.to.simplify.multi-homed.web.servers.and.conserve.ip.addresses" title="Changes to Simplify Multi-homed Web Servers and Conserve IP Addresses">B.1.1</a> for other requirements relating to Host.
    18441844      </p>
    18451845      <div id="rfc.iref.t.2"></div>
    18461846      <div id="rfc.iref.h.11"></div>
    1847       <h2 id="rfc.section.8.5"><a href="#rfc.section.8.5">8.5</a>&nbsp;<a id="header.te" href="#header.te">TE</a></h2>
    1848       <p id="rfc.section.8.5.p.1">The request-header field "TE" indicates what extension transfer-codings it is willing to accept in the response and whether
     1847      <h2 id="rfc.section.3.5"><a href="#rfc.section.3.5">3.5</a>&nbsp;<a id="header.te" href="#header.te">TE</a></h2>
     1848      <p id="rfc.section.3.5.p.1">The request-header field "TE" indicates what extension transfer-codings it is willing to accept in the response and whether
    18491849         or not it is willing to accept trailer fields in a chunked transfer-coding. Its value may consist of the keyword "trailers"
    1850          and/or a comma-separated list of extension transfer-coding names with optional accept parameters (as described in <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;6.2</a>).
     1850         and/or a comma-separated list of extension transfer-coding names with optional accept parameters (as described in <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;2.10.2</a>).
    18511851      </p>
    18521852      <div id="rfc.figure.u.60"></div><pre class="inline"><span id="rfc.iref.g.98"></span><span id="rfc.iref.g.99"></span><span id="rfc.iref.g.100"></span><span id="rfc.iref.g.101"></span><span id="rfc.iref.g.102"></span>  <a href="#header.te" class="smpl">TE</a>        = "TE" ":" <a href="#rule.whitespace" class="smpl">OWS</a> <a href="#header.te" class="smpl">TE-v</a>
     
    18551855  <a href="#header.te" class="smpl">te-params</a> = <a href="#rule.whitespace" class="smpl">OWS</a> ";" <a href="#rule.whitespace" class="smpl">OWS</a> "q=" <a href="#quality.values" class="smpl">qvalue</a> *( <a href="#header.te" class="smpl">te-ext</a> )
    18561856  <a href="#header.te" class="smpl">te-ext</a>    = <a href="#rule.whitespace" class="smpl">OWS</a> ";" <a href="#rule.whitespace" class="smpl">OWS</a> <a href="#rule.token.separators" class="smpl">token</a> [ "=" ( <a href="#rule.token.separators" class="smpl">token</a> / <a href="#rule.quoted-string" class="smpl">quoted-string</a> ) ]
    1857 </pre><p id="rfc.section.8.5.p.3">The presence of the keyword "trailers" indicates that the client is willing to accept trailer fields in a chunked transfer-coding,
    1858          as defined in <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;6.2.1</a>. This keyword is reserved for use with transfer-coding values even though it does not itself represent a transfer-coding.
    1859       </p>
    1860       <p id="rfc.section.8.5.p.4">Examples of its use are:</p>
     1857</pre><p id="rfc.section.3.5.p.3">The presence of the keyword "trailers" indicates that the client is willing to accept trailer fields in a chunked transfer-coding,
     1858         as defined in <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;2.10.2.1</a>. This keyword is reserved for use with transfer-coding values even though it does not itself represent a transfer-coding.
     1859      </p>
     1860      <p id="rfc.section.3.5.p.4">Examples of its use are:</p>
    18611861      <div id="rfc.figure.u.61"></div><pre class="text">  TE: deflate
    18621862  TE:
    18631863  TE: trailers, deflate;q=0.5
    1864 </pre><p id="rfc.section.8.5.p.6">The TE header field only applies to the immediate connection. Therefore, the keyword <em class="bcp14">MUST</em> be supplied within a Connection header field (<a href="#header.connection" id="rfc.xref.header.connection.4" title="Connection">Section&nbsp;8.1</a>) whenever TE is present in an HTTP/1.1 message.
    1865       </p>
    1866       <p id="rfc.section.8.5.p.7">A server tests whether a transfer-coding is acceptable, according to a TE field, using these rules: </p>
     1864</pre><p id="rfc.section.3.5.p.6">The TE header field only applies to the immediate connection. Therefore, the keyword <em class="bcp14">MUST</em> be supplied within a Connection header field (<a href="#header.connection" id="rfc.xref.header.connection.4" title="Connection">Section&nbsp;3.1</a>) whenever TE is present in an HTTP/1.1 message.
     1865      </p>
     1866      <p id="rfc.section.3.5.p.7">A server tests whether a transfer-coding is acceptable, according to a TE field, using these rules: </p>
    18671867      <ol>
    18681868         <li>
     
    18781878         <li>
    18791879            <p>If the transfer-coding being tested is one of the transfer-codings listed in the TE field, then it is acceptable unless it
    1880                is accompanied by a qvalue of 0. (As defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.4</a>, a qvalue of 0 means "not acceptable.")
     1880               is accompanied by a qvalue of 0. (As defined in <a href="#quality.values" title="Quality Values">Section&nbsp;2.10.4</a>, a qvalue of 0 means "not acceptable.")
    18811881            </p>
    18821882         </li>
     
    18871887         </li>
    18881888      </ol>
    1889       <p id="rfc.section.8.5.p.8">If the TE field-value is empty or if no TE field is present, the only transfer-coding is "chunked". A message with no transfer-coding
     1889      <p id="rfc.section.3.5.p.8">If the TE field-value is empty or if no TE field is present, the only transfer-coding is "chunked". A message with no transfer-coding
    18901890         is always acceptable.
    18911891      </p>
    18921892      <div id="rfc.iref.t.3"></div>
    18931893      <div id="rfc.iref.h.12"></div>
    1894       <h2 id="rfc.section.8.6"><a href="#rfc.section.8.6">8.6</a>&nbsp;<a id="header.trailer" href="#header.trailer">Trailer</a></h2>
    1895       <p id="rfc.section.8.6.p.1">The general field "Trailer" indicates that the given set of header fields is present in the trailer of a message encoded with
     1894      <h2 id="rfc.section.3.6"><a href="#rfc.section.3.6">3.6</a>&nbsp;<a id="header.trailer" href="#header.trailer">Trailer</a></h2>
     1895      <p id="rfc.section.3.6.p.1">The general field "Trailer" indicates that the given set of header fields is present in the trailer of a message encoded with
    18961896         chunked transfer-coding.
    18971897      </p>
    18981898      <div id="rfc.figure.u.62"></div><pre class="inline"><span id="rfc.iref.g.103"></span><span id="rfc.iref.g.104"></span>  <a href="#header.trailer" class="smpl">Trailer</a>   = "Trailer" ":" <a href="#rule.whitespace" class="smpl">OWS</a> <a href="#header.trailer" class="smpl">Trailer-v</a>
    18991899  <a href="#header.trailer" class="smpl">Trailer-v</a> = 1#<a href="#header.fields" class="smpl">field-name</a>
    1900 </pre><p id="rfc.section.8.6.p.3">An HTTP/1.1 message <em class="bcp14">SHOULD</em> include a Trailer header field in a message using chunked transfer-coding with a non-empty trailer. Doing so allows the recipient
     1900</pre><p id="rfc.section.3.6.p.3">An HTTP/1.1 message <em class="bcp14">SHOULD</em> include a Trailer header field in a message using chunked transfer-coding with a non-empty trailer. Doing so allows the recipient
    19011901         to know which header fields to expect in the trailer.
    19021902      </p>
    1903       <p id="rfc.section.8.6.p.4">If no Trailer header field is present, the trailer <em class="bcp14">SHOULD NOT</em> include any header fields. See <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;6.2.1</a> for restrictions on the use of trailer fields in a "chunked" transfer-coding.
    1904       </p>
    1905       <p id="rfc.section.8.6.p.5">Message header fields listed in the Trailer header field <em class="bcp14">MUST NOT</em> include the following header fields:
     1903      <p id="rfc.section.3.6.p.4">If no Trailer header field is present, the trailer <em class="bcp14">SHOULD NOT</em> include any header fields. See <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;2.10.2.1</a> for restrictions on the use of trailer fields in a "chunked" transfer-coding.
     1904      </p>
     1905      <p id="rfc.section.3.6.p.5">Message header fields listed in the Trailer header field <em class="bcp14">MUST NOT</em> include the following header fields:
    19061906      </p>
    19071907      <ul>
     
    19121912      <div id="rfc.iref.t.4"></div>
    19131913      <div id="rfc.iref.h.13"></div>
    1914       <h2 id="rfc.section.8.7"><a href="#rfc.section.8.7">8.7</a>&nbsp;<a id="header.transfer-encoding" href="#header.transfer-encoding">Transfer-Encoding</a></h2>
    1915       <p id="rfc.section.8.7.p.1">The general-header "Transfer-Encoding" field indicates what (if any) type of transformation has been applied to the message
     1914      <h2 id="rfc.section.3.7"><a href="#rfc.section.3.7">3.7</a>&nbsp;<a id="header.transfer-encoding" href="#header.transfer-encoding">Transfer-Encoding</a></h2>
     1915      <p id="rfc.section.3.7.p.1">The general-header "Transfer-Encoding" field indicates what (if any) type of transformation has been applied to the message
    19161916         body in order to safely transfer it between the sender and the recipient. This differs from the content-coding in that the
    19171917         transfer-coding is a property of the message, not of the entity.
     
    19201920                        <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding-v</a>
    19211921  <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding-v</a> = 1#<a href="#transfer.codings" class="smpl">transfer-coding</a>
    1922 </pre><p id="rfc.section.8.7.p.3">Transfer-codings are defined in <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;6.2</a>. An example is:
     1922</pre><p id="rfc.section.3.7.p.3">Transfer-codings are defined in <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;2.10.2</a>. An example is:
    19231923      </p>
    19241924      <div id="rfc.figure.u.64"></div><pre class="text">  Transfer-Encoding: chunked
    1925 </pre><p id="rfc.section.8.7.p.5">If multiple encodings have been applied to an entity, the transfer-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 entity-header fields not defined by this specification.
    1926       </p>
    1927       <p id="rfc.section.8.7.p.6">Many older HTTP/1.0 applications do not understand the Transfer-Encoding header.</p>
     1925</pre><p id="rfc.section.3.7.p.5">If multiple encodings have been applied to an entity, the transfer-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 entity-header fields not defined by this specification.
     1926      </p>
     1927      <p id="rfc.section.3.7.p.6">Many older HTTP/1.0 applications do not understand the Transfer-Encoding header.</p>
    19281928      <div id="rfc.iref.u.5"></div>
    19291929      <div id="rfc.iref.h.14"></div>
    1930       <h2 id="rfc.section.8.8"><a href="#rfc.section.8.8">8.8</a>&nbsp;<a id="header.upgrade" href="#header.upgrade">Upgrade</a></h2>
    1931       <p id="rfc.section.8.8.p.1">The general-header "Upgrade" allows the client to specify what additional communication protocols it supports and would like
     1930      <h2 id="rfc.section.3.8"><a href="#rfc.section.3.8">3.8</a>&nbsp;<a id="header.upgrade" href="#header.upgrade">Upgrade</a></h2>
     1931      <p id="rfc.section.3.8.p.1">The general-header "Upgrade" allows the client to specify what additional communication protocols it supports and would like
    19321932         to use if the server finds it appropriate to switch protocols. The server <em class="bcp14">MUST</em> use the Upgrade header field within a 101 (Switching Protocols) response to indicate which protocol(s) are being switched.
    19331933      </p>
    19341934      <div id="rfc.figure.u.65"></div><pre class="inline"><span id="rfc.iref.g.107"></span><span id="rfc.iref.g.108"></span>  <a href="#header.upgrade" class="smpl">Upgrade</a>   = "Upgrade" ":" <a href="#rule.whitespace" class="smpl">OWS</a> <a href="#header.upgrade" class="smpl">Upgrade-v</a>
    19351935  <a href="#header.upgrade" class="smpl">Upgrade-v</a> = 1#<a href="#product.tokens" class="smpl">product</a>
    1936 </pre><p id="rfc.section.8.8.p.3">For example,</p>
     1936</pre><p id="rfc.section.3.8.p.3">For example,</p>
    19371937      <div id="rfc.figure.u.66"></div><pre class="text">  Upgrade: HTTP/2.0, SHTTP/1.3, IRC/6.9, RTA/x11
    1938 </pre><p id="rfc.section.8.8.p.5">The Upgrade header field is intended to provide a simple mechanism for transition from HTTP/1.1 to some other, incompatible
     1938</pre><p id="rfc.section.3.8.p.5">The Upgrade header field is intended to provide a simple mechanism for transition from HTTP/1.1 to some other, incompatible
    19391939         protocol. It does so by allowing the client to advertise its desire to use another protocol, such as a later version of HTTP
    19401940         with a higher major version number, even though the current request has been made using HTTP/1.1. This eases the difficult
     
    19431943         the server, possibly according to the nature of the method and/or resource being requested).
    19441944      </p>
    1945       <p id="rfc.section.8.8.p.6">The Upgrade header field only applies to switching application-layer protocols upon the existing transport-layer connection.
     1945      <p id="rfc.section.3.8.p.6">The Upgrade header field only applies to switching application-layer protocols upon the existing transport-layer connection.
    19461946         Upgrade cannot be used to insist on a protocol change; its acceptance and use by the server is optional. The capabilities
    19471947         and nature of the application-layer communication after the protocol change is entirely dependent upon the new protocol chosen,
    19481948         although the first action after changing the protocol <em class="bcp14">MUST</em> be a response to the initial HTTP request containing the Upgrade header field.
    19491949      </p>
    1950       <p id="rfc.section.8.8.p.7">The Upgrade header field only applies to the immediate connection. Therefore, the upgrade keyword <em class="bcp14">MUST</em> be supplied within a Connection header field (<a href="#header.connection" id="rfc.xref.header.connection.5" title="Connection">Section&nbsp;8.1</a>) whenever Upgrade is present in an HTTP/1.1 message.
    1951       </p>
    1952       <p id="rfc.section.8.8.p.8">The Upgrade header field cannot be used to indicate a switch to a protocol on a different connection. For that purpose, it
     1950      <p id="rfc.section.3.8.p.7">The Upgrade header field only applies to the immediate connection. Therefore, the upgrade keyword <em class="bcp14">MUST</em> be supplied within a Connection header field (<a href="#header.connection" id="rfc.xref.header.connection.5" title="Connection">Section&nbsp;3.1</a>) whenever Upgrade is present in an HTTP/1.1 message.
     1951      </p>
     1952      <p id="rfc.section.3.8.p.8">The Upgrade header field cannot be used to indicate a switch to a protocol on a different connection. For that purpose, it
    19531953         is more appropriate to use a 301, 302, 303, or 305 redirection response.
    19541954      </p>
    1955       <p id="rfc.section.8.8.p.9">This specification only defines the protocol name "HTTP" for use by the family of Hypertext Transfer Protocols, as defined
     1955      <p id="rfc.section.3.8.p.9">This specification only defines the protocol name "HTTP" for use by the family of Hypertext Transfer Protocols, as defined
    19561956         by the HTTP version rules of <a href="#http.version" title="HTTP Version">Section&nbsp;2.5</a> and future updates to this specification. Any token can be used as a protocol name; however, it will only be useful if both
    19571957         the client and server associate the name with the same protocol.
     
    19591959      <div id="rfc.iref.v.1"></div>
    19601960      <div id="rfc.iref.h.15"></div>
    1961       <h2 id="rfc.section.8.9"><a href="#rfc.section.8.9">8.9</a>&nbsp;<a id="header.via" href="#header.via">Via</a></h2>
    1962       <p id="rfc.section.8.9.p.1">The general-header field "Via" <em class="bcp14">MUST</em> be used by gateways and proxies to indicate the intermediate protocols and recipients between the user agent and the server
     1961      <h2 id="rfc.section.3.9"><a href="#rfc.section.3.9">3.9</a>&nbsp;<a id="header.via" href="#header.via">Via</a></h2>
     1962      <p id="rfc.section.3.9.p.1">The general-header field "Via" <em class="bcp14">MUST</em> be used by gateways and proxies to indicate the intermediate protocols and recipients between the user agent and the server
    19631963         on requests, and between the origin server and the client on responses. It is analogous to the "Received" field defined in <a href="http://tools.ietf.org/html/rfc5322#section-3.6.7">Section 3.6.7</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.5"><cite title="Internet Message Format">[RFC5322]</cite></a> and is intended to be used for tracking message forwards, avoiding request loops, and identifying the protocol capabilities
    19641964         of all senders along the request/response chain.
     
    19721972  <a href="#header.via" class="smpl">received-by</a>       = ( <a href="#uri" class="smpl">uri-host</a> [ ":" <a href="#uri" class="smpl">port</a> ] ) / <a href="#header.via" class="smpl">pseudonym</a>
    19731973  <a href="#header.via" class="smpl">pseudonym</a>         = <a href="#rule.token.separators" class="smpl">token</a>
    1974 </pre><p id="rfc.section.8.9.p.3">The received-protocol indicates the protocol version of the message received by the server or client along each segment of
     1974</pre><p id="rfc.section.3.9.p.3">The received-protocol indicates the protocol version of the message received by the server or client along each segment of
    19751975         the request/response chain. The received-protocol version is appended to the Via field value when the message is forwarded
    19761976         so that information about the protocol capabilities of upstream applications remains visible to all recipients.
    19771977      </p>
    1978       <p id="rfc.section.8.9.p.4">The protocol-name is optional if and only if it would be "HTTP". The received-by field is normally the host and optional port
     1978      <p id="rfc.section.3.9.p.4">The protocol-name is optional if and only if it would be "HTTP". The received-by field is normally the host and optional port
    19791979         number of a recipient server or client that subsequently forwarded the message. However, if the real host is considered to
    19801980         be sensitive information, it <em class="bcp14">MAY</em> be replaced by a pseudonym. If the port is not given, it <em class="bcp14">MAY</em> be assumed to be the default port of the received-protocol.
    19811981      </p>
    1982       <p id="rfc.section.8.9.p.5">Multiple Via field values represents each proxy or gateway that has forwarded the message. Each recipient <em class="bcp14">MUST</em> append its information such that the end result is ordered according to the sequence of forwarding applications.
    1983       </p>
    1984       <p id="rfc.section.8.9.p.6">Comments <em class="bcp14">MAY</em> be used in the Via header field to identify the software of the recipient proxy or gateway, analogous to the User-Agent and
     1982      <p id="rfc.section.3.9.p.5">Multiple Via field values represents each proxy or gateway that has forwarded the message. Each recipient <em class="bcp14">MUST</em> append its information such that the end result is ordered according to the sequence of forwarding applications.
     1983      </p>
     1984      <p id="rfc.section.3.9.p.6">Comments <em class="bcp14">MAY</em> be used in the Via header field to identify the software of the recipient proxy or gateway, analogous to the User-Agent and
    19851985         Server header fields. However, all comments in the Via field are optional and <em class="bcp14">MAY</em> be removed by any recipient prior to forwarding the message.
    19861986      </p>
    1987       <p id="rfc.section.8.9.p.7">For example, a request message could be sent from an HTTP/1.0 user agent to an internal proxy code-named "fred", which uses
     1987      <p id="rfc.section.3.9.p.7">For example, a request message could be sent from an HTTP/1.0 user agent to an internal proxy code-named "fred", which uses
    19881988         HTTP/1.1 to forward the request to a public proxy at p.example.net, which completes the request by forwarding it to the origin
    19891989         server at www.example.com. The request received by www.example.com would then have the following Via header field:
    19901990      </p>
    19911991      <div id="rfc.figure.u.68"></div><pre class="text">  Via: 1.0 fred, 1.1 p.example.net (Apache/1.1)
    1992 </pre><p id="rfc.section.8.9.p.9">Proxies and gateways used as a portal through a network firewall <em class="bcp14">SHOULD NOT</em>, by default, forward the names and ports of hosts within the firewall region. This information <em class="bcp14">SHOULD</em> only be propagated if explicitly enabled. If not enabled, the received-by host of any host behind the firewall <em class="bcp14">SHOULD</em> be replaced by an appropriate pseudonym for that host.
    1993       </p>
    1994       <p id="rfc.section.8.9.p.10">For organizations that have strong privacy requirements for hiding internal structures, a proxy <em class="bcp14">MAY</em> combine an ordered subsequence of Via header field entries with identical received-protocol values into a single such entry.
     1992</pre><p id="rfc.section.3.9.p.9">Proxies and gateways used as a portal through a network firewall <em class="bcp14">SHOULD NOT</em>, by default, forward the names and ports of hosts within the firewall region. This information <em class="bcp14">SHOULD</em> only be propagated if explicitly enabled. If not enabled, the received-by host of any host behind the firewall <em class="bcp14">SHOULD</em> be replaced by an appropriate pseudonym for that host.
     1993      </p>
     1994      <p id="rfc.section.3.9.p.10">For organizations that have strong privacy requirements for hiding internal structures, a proxy <em class="bcp14">MAY</em> combine an ordered subsequence of Via header field entries with identical received-protocol values into a single such entry.
    19951995         For example,
    19961996      </p>
    19971997      <div id="rfc.figure.u.69"></div><pre class="text">  Via: 1.0 ricky, 1.1 ethel, 1.1 fred, 1.0 lucy
    1998 </pre><p id="rfc.section.8.9.p.12">could be collapsed to</p>
     1998</pre><p id="rfc.section.3.9.p.12">could be collapsed to</p>
    19991999      <div id="rfc.figure.u.70"></div><pre class="text">  Via: 1.0 ricky, 1.1 mertz, 1.0 lucy
    2000 </pre><p id="rfc.section.8.9.p.14">Applications <em class="bcp14">SHOULD NOT</em> combine multiple entries unless they are all under the same organizational control and the hosts have already been replaced
     2000</pre><p id="rfc.section.3.9.p.14">Applications <em class="bcp14">SHOULD NOT</em> combine multiple entries unless they are all under the same organizational control and the hosts have already been replaced
    20012001         by pseudonyms. Applications <em class="bcp14">MUST NOT</em> combine entries which have different received-protocol values.
    20022002      </p>
    2003       <h1 id="rfc.section.9"><a href="#rfc.section.9">9.</a>&nbsp;<a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>
    2004       <h2 id="rfc.section.9.1"><a href="#rfc.section.9.1">9.1</a>&nbsp;<a id="message.header.registration" href="#message.header.registration">Message Header Registration</a></h2>
    2005       <p id="rfc.section.9.1.p.1">The Message Header Registry located at &lt;<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>&gt; should be updated with the permanent registrations below (see <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>):
     2003      <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>
     2004      <h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a>&nbsp;<a id="message.header.registration" href="#message.header.registration">Message Header Registration</a></h2>
     2005      <p id="rfc.section.4.1.p.1">The Message Header Registry located at &lt;<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>&gt; should be updated with the permanent registrations below (see <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>):
    20062006      </p>
    20072007      <div id="rfc.table.1">
     
    20212021                  <td>http</td>
    20222022                  <td>standard</td>
    2023                   <td> <a href="#header.connection" id="rfc.xref.header.connection.6" title="Connection">Section&nbsp;8.1</a>
     2023                  <td> <a href="#header.connection" id="rfc.xref.header.connection.6" title="Connection">Section&nbsp;3.1</a>
    20242024                  </td>
    20252025               </tr>
     
    20282028                  <td>http</td>
    20292029                  <td>standard</td>
    2030                   <td> <a href="#header.content-length" id="rfc.xref.header.content-length.2" title="Content-Length">Section&nbsp;8.2</a>
     2030                  <td> <a href="#header.content-length" id="rfc.xref.header.content-length.2" title="Content-Length">Section&nbsp;3.2</a>
    20312031                  </td>
    20322032               </tr>
     
    20352035                  <td>http</td>
    20362036                  <td>standard</td>
    2037                   <td> <a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section&nbsp;8.3</a>
     2037                  <td> <a href="#header.date" id="rfc.xref.header.date.2" title="Date">Section&nbsp;3.3</a>
    20382038                  </td>
    20392039               </tr>
     
    20422042                  <td>http</td>
    20432043                  <td>standard</td>
    2044                   <td> <a href="#header.host" id="rfc.xref.header.host.1" title="Host">Section&nbsp;8.4</a>
     2044                  <td> <a href="#header.host" id="rfc.xref.header.host.1" title="Host">Section&nbsp;3.4</a>
    20452045                  </td>
    20462046               </tr>
     
    20492049                  <td>http</td>
    20502050                  <td>standard</td>
    2051                   <td> <a href="#header.te" id="rfc.xref.header.te.4" title="TE">Section&nbsp;8.5</a>
     2051                  <td> <a href="#header.te" id="rfc.xref.header.te.4" title="TE">Section&nbsp;3.5</a>
    20522052                  </td>
    20532053               </tr>
     
    20562056                  <td>http</td>
    20572057                  <td>standard</td>
    2058                   <td> <a href="#header.trailer" id="rfc.xref.header.trailer.3" title="Trailer">Section&nbsp;8.6</a>
     2058                  <td> <a href="#header.trailer" id="rfc.xref.header.trailer.3" title="Trailer">Section&nbsp;3.6</a>
    20592059                  </td>
    20602060               </tr>
     
    20632063                  <td>http</td>
    20642064                  <td>standard</td>
    2065                   <td> <a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.5" title="Transfer-Encoding">Section&nbsp;8.7</a>
     2065                  <td> <a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.5" title="Transfer-Encoding">Section&nbsp;3.7</a>
    20662066                  </td>
    20672067               </tr>
     
    20702070                  <td>http</td>
    20712071                  <td>standard</td>
    2072                   <td> <a href="#header.upgrade" id="rfc.xref.header.upgrade.2" title="Upgrade">Section&nbsp;8.8</a>
     2072                  <td> <a href="#header.upgrade" id="rfc.xref.header.upgrade.2" title="Upgrade">Section&nbsp;3.8</a>
    20732073                  </td>
    20742074               </tr>
     
    20772077                  <td>http</td>
    20782078                  <td>standard</td>
    2079                   <td> <a href="#header.via" id="rfc.xref.header.via.2" title="Via">Section&nbsp;8.9</a>
     2079                  <td> <a href="#header.via" id="rfc.xref.header.via.2" title="Via">Section&nbsp;3.9</a>
    20802080                  </td>
    20812081               </tr>
     
    20832083         </table>
    20842084      </div>
    2085       <p id="rfc.section.9.1.p.2">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
    2086       <h2 id="rfc.section.9.2"><a href="#rfc.section.9.2">9.2</a>&nbsp;<a id="uri.scheme.registration" href="#uri.scheme.registration">URI Scheme Registration</a></h2>
    2087       <p id="rfc.section.9.2.p.1">The entries for the "http" and "https" URI Schemes in the registry located at &lt;<a href="http://www.iana.org/assignments/uri-schemes.html">http://www.iana.org/assignments/uri-schemes.html</a>&gt; should be updated to point to Sections <a href="#http.uri" title="http URI scheme">2.6.1</a> and <a href="#https.uri" title="https URI scheme">2.6.2</a> of this document (see <a href="#RFC4395" id="rfc.xref.RFC4395.1"><cite title="Guidelines and Registration Procedures for New URI Schemes">[RFC4395]</cite></a>).
    2088       </p>
    2089       <h2 id="rfc.section.9.3"><a href="#rfc.section.9.3">9.3</a>&nbsp;<a id="internet.media.type.http" href="#internet.media.type.http">Internet Media Type Registrations</a></h2>
    2090       <p id="rfc.section.9.3.p.1">This document serves as the specification for the Internet media types "message/http" and "application/http". The following
     2085      <p id="rfc.section.4.1.p.2">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
     2086      <h2 id="rfc.section.4.2"><a href="#rfc.section.4.2">4.2</a>&nbsp;<a id="uri.scheme.registration" href="#uri.scheme.registration">URI Scheme Registration</a></h2>
     2087      <p id="rfc.section.4.2.p.1">The entries for the "http" and "https" URI Schemes in the registry located at &lt;<a href="http://www.iana.org/assignments/uri-schemes.html">http://www.iana.org/assignments/uri-schemes.html</a>&gt; should be updated to point to Sections <a href="#http.uri" title="http URI scheme">2.6.1</a> and <a href="#https.uri" title="https URI scheme">2.6.2</a> of this document (see <a href="#RFC4395" id="rfc.xref.RFC4395.1"><cite title="Guidelines and Registration Procedures for New URI Schemes">[RFC4395]</cite></a>).
     2088      </p>
     2089      <h2 id="rfc.section.4.3"><a href="#rfc.section.4.3">4.3</a>&nbsp;<a id="internet.media.type.http" href="#internet.media.type.http">Internet Media Type Registrations</a></h2>
     2090      <p id="rfc.section.4.3.p.1">This document serves as the specification for the Internet media types "message/http" and "application/http". The following
    20912091         is to be registered with IANA (see <a href="#RFC4288" id="rfc.xref.RFC4288.1"><cite title="Media Type Specifications and Registration Procedures">[RFC4288]</cite></a>).
    20922092      </p>
    20932093      <div id="rfc.iref.m.2"></div>
    20942094      <div id="rfc.iref.m.3"></div>
    2095       <h3 id="rfc.section.9.3.1"><a href="#rfc.section.9.3.1">9.3.1</a>&nbsp;<a id="internet.media.type.message.http" href="#internet.media.type.message.http">Internet Media Type message/http</a></h3>
    2096       <p id="rfc.section.9.3.1.p.1">The message/http type can be used to enclose a single HTTP request or response message, provided that it obeys the MIME restrictions
     2095      <h3 id="rfc.section.4.3.1"><a href="#rfc.section.4.3.1">4.3.1</a>&nbsp;<a id="internet.media.type.message.http" href="#internet.media.type.message.http">Internet Media Type message/http</a></h3>
     2096      <p id="rfc.section.4.3.1.p.1">The message/http type can be used to enclose a single HTTP request or response message, provided that it obeys the MIME restrictions
    20972097         for all "message" types regarding line length and encodings.
    20982098      </p>
    2099       <p id="rfc.section.9.3.1.p.2"> </p>
     2099      <p id="rfc.section.4.3.1.p.2"> </p>
    21002100      <dl>
    21012101         <dt>Type name:</dt>
     
    21232123         <dd>none</dd>
    21242124         <dt>Published specification:</dt>
    2125          <dd>This specification (see <a href="#internet.media.type.message.http" title="Internet Media Type message/http">Section&nbsp;9.3.1</a>).
     2125         <dd>This specification (see <a href="#internet.media.type.message.http" title="Internet Media Type message/http">Section&nbsp;4.3.1</a>).
    21262126         </dd>
    21272127         <dt>Applications that use this media type:</dt>
     
    21482148      <div id="rfc.iref.m.4"></div>
    21492149      <div id="rfc.iref.a.1"></div>
    2150       <h3 id="rfc.section.9.3.2"><a href="#rfc.section.9.3.2">9.3.2</a>&nbsp;<a id="internet.media.type.application.http" href="#internet.media.type.application.http">Internet Media Type application/http</a></h3>
    2151       <p id="rfc.section.9.3.2.p.1">The application/http type can be used to enclose a pipeline of one or more HTTP request or response messages (not intermixed).</p>
    2152       <p id="rfc.section.9.3.2.p.2"> </p>
     2150      <h3 id="rfc.section.4.3.2"><a href="#rfc.section.4.3.2">4.3.2</a>&nbsp;<a id="internet.media.type.application.http" href="#internet.media.type.application.http">Internet Media Type application/http</a></h3>
     2151      <p id="rfc.section.4.3.2.p.1">The application/http type can be used to enclose a pipeline of one or more HTTP request or response messages (not intermixed).</p>
     2152      <p id="rfc.section.4.3.2.p.2"> </p>
    21532153      <dl>
    21542154         <dt>Type name:</dt>
     
    21782178         <dd>none</dd>
    21792179         <dt>Published specification:</dt>
    2180          <dd>This specification (see <a href="#internet.media.type.application.http" title="Internet Media Type application/http">Section&nbsp;9.3.2</a>).
     2180         <dd>This specification (see <a href="#internet.media.type.application.http" title="Internet Media Type application/http">Section&nbsp;4.3.2</a>).
    21812181         </dd>
    21822182         <dt>Applications that use this media type:</dt>
     
    22012201         <dd>IESG</dd>
    22022202      </dl>
    2203       <h1 id="rfc.section.10"><a href="#rfc.section.10">10.</a>&nbsp;<a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>
    2204       <p id="rfc.section.10.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1
     2203      <h2 id="rfc.section.4.4"><a href="#rfc.section.4.4">4.4</a>&nbsp;<a id="transfer.coding.registration" href="#transfer.coding.registration">Transfer Coding Registry</a></h2>
     2204      <p id="rfc.section.4.4.p.1">The registration procedure for HTTP Transfer Codings is now defined by <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;2.10.2</a> of this document.
     2205      </p>
     2206      <p id="rfc.section.4.4.p.2">The HTTP Transfer Codings Registry located at &lt;<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>&gt; should be updated with the registration below:
     2207      </p>
     2208      <div id="rfc.table.2">
     2209         <div id="iana.transfer.coding.registration.table"></div>
     2210         <table summary="" class="tt full" cellpadding="3" cellspacing="0">
     2211            <thead>
     2212               <tr>
     2213                  <th>Registry Name</th>
     2214                  <th>Description</th>
     2215                  <th>Reference</th>
     2216               </tr>
     2217            </thead>
     2218            <tbody>
     2219               <tr>
     2220                  <td>Chunked</td>
     2221                  <td>Transfer in a series of chunks</td>
     2222                  <td> <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;2.10.2.1</a>
     2223                  </td>
     2224               </tr>
     2225            </tbody>
     2226         </table>
     2227      </div>
     2228      <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>
     2229      <p id="rfc.section.5.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1
    22052230         as described by this document. The discussion does not include definitive solutions to the problems revealed, though it does
    22062231         make some suggestions for reducing security risks.
    22072232      </p>
    2208       <h2 id="rfc.section.10.1"><a href="#rfc.section.10.1">10.1</a>&nbsp;<a id="personal.information" href="#personal.information">Personal Information</a></h2>
    2209       <p id="rfc.section.10.1.p.1">HTTP clients are often privy to large amounts of personal information (e.g. the user's name, location, mail address, passwords,
     2233      <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a>&nbsp;<a id="personal.information" href="#personal.information">Personal Information</a></h2>
     2234      <p id="rfc.section.5.1.p.1">HTTP clients are often privy to large amounts of personal information (e.g. the user's name, location, mail address, passwords,
    22102235         encryption keys, etc.), and <em class="bcp14">SHOULD</em> be very careful to prevent unintentional leakage of this information. We very strongly recommend that a convenient interface
    22112236         be provided for the user to control dissemination of such information, and that designers and implementors be particularly
     
    22132238         highly adverse publicity for the implementor's company.
    22142239      </p>
    2215       <h2 id="rfc.section.10.2"><a href="#rfc.section.10.2">10.2</a>&nbsp;<a id="abuse.of.server.log.information" href="#abuse.of.server.log.information">Abuse of Server Log Information</a></h2>
    2216       <p id="rfc.section.10.2.p.1">A server is in the position to save personal data about a user's requests which might identify their reading patterns or subjects
     2240      <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</a>&nbsp;<a id="abuse.of.server.log.information" href="#abuse.of.server.log.information">Abuse of Server Log Information</a></h2>
     2241      <p id="rfc.section.5.2.p.1">A server is in the position to save personal data about a user's requests which might identify their reading patterns or subjects
    22172242         of interest. This information is clearly confidential in nature and its handling can be constrained by law in certain countries.
    22182243         People using HTTP to provide data are responsible for ensuring that such material is not distributed without the permission
    22192244         of any individuals that are identifiable by the published results.
    22202245      </p>
    2221       <h2 id="rfc.section.10.3"><a href="#rfc.section.10.3">10.3</a>&nbsp;<a id="attack.pathname" href="#attack.pathname">Attacks Based On File and Path Names</a></h2>
    2222       <p id="rfc.section.10.3.p.1">Implementations of HTTP origin servers <em class="bcp14">SHOULD</em> be careful to restrict the documents returned by HTTP requests to be only those that were intended by the server administrators.
     2246      <h2 id="rfc.section.5.3"><a href="#rfc.section.5.3">5.3</a>&nbsp;<a id="attack.pathname" href="#attack.pathname">Attacks Based On File and Path Names</a></h2>
     2247      <p id="rfc.section.5.3.p.1">Implementations of HTTP origin servers <em class="bcp14">SHOULD</em> be careful to restrict the documents returned by HTTP requests to be only those that were intended by the server administrators.
    22232248         If an HTTP server translates HTTP URIs directly into file system calls, the server <em class="bcp14">MUST</em> take special care not to serve files that were not intended to be delivered to HTTP clients. For example, UNIX, Microsoft
    22242249         Windows, and other operating systems use ".." as a path component to indicate a directory level above the current one. On
     
    22282253         bugs in such HTTP server implementations have turned into security risks.
    22292254      </p>
    2230       <h2 id="rfc.section.10.4"><a href="#rfc.section.10.4">10.4</a>&nbsp;<a id="dns.spoofing" href="#dns.spoofing">DNS Spoofing</a></h2>
    2231       <p id="rfc.section.10.4.p.1">Clients using HTTP rely heavily on the Domain Name Service, and are thus generally prone to security attacks based on the
     2255      <h2 id="rfc.section.5.4"><a href="#rfc.section.5.4">5.4</a>&nbsp;<a id="dns.spoofing" href="#dns.spoofing">DNS Spoofing</a></h2>
     2256      <p id="rfc.section.5.4.p.1">Clients using HTTP rely heavily on the Domain Name Service, and are thus generally prone to security attacks based on the
    22322257         deliberate mis-association of IP addresses and DNS names. Clients need to be cautious in assuming the continuing validity
    22332258         of an IP number/DNS name association.
    22342259      </p>
    2235       <p id="rfc.section.10.4.p.2">In particular, HTTP clients <em class="bcp14">SHOULD</em> rely on their name resolver for confirmation of an IP number/DNS name association, rather than caching the result of previous
     2260      <p id="rfc.section.5.4.p.2">In particular, HTTP clients <em class="bcp14">SHOULD</em> rely on their name resolver for confirmation of an IP number/DNS name association, rather than caching the result of previous
    22362261         host name lookups. Many platforms already can cache host name lookups locally when appropriate, and they <em class="bcp14">SHOULD</em> be configured to do so. It is proper for these lookups to be cached, however, only when the TTL (Time To Live) information
    22372262         reported by the name server makes it likely that the cached information will remain useful.
    22382263      </p>
    2239       <p id="rfc.section.10.4.p.3">If HTTP clients cache the results of host name lookups in order to achieve a performance improvement, they <em class="bcp14">MUST</em> observe the TTL information reported by DNS.
    2240       </p>
    2241       <p id="rfc.section.10.4.p.4">If HTTP clients do not observe this rule, they could be spoofed when a previously-accessed server's IP address changes. As
     2264      <p id="rfc.section.5.4.p.3">If HTTP clients cache the results of host name lookups in order to achieve a performance improvement, they <em class="bcp14">MUST</em> observe the TTL information reported by DNS.
     2265      </p>
     2266      <p id="rfc.section.5.4.p.4">If HTTP clients do not observe this rule, they could be spoofed when a previously-accessed server's IP address changes. As
    22422267         network renumbering is expected to become increasingly common <a href="#RFC1900" id="rfc.xref.RFC1900.1"><cite title="Renumbering Needs Work">[RFC1900]</cite></a>, the possibility of this form of attack will grow. Observing this requirement thus reduces this potential security vulnerability.
    22432268      </p>
    2244       <p id="rfc.section.10.4.p.5">This requirement also improves the load-balancing behavior of clients for replicated servers using the same DNS name and reduces
     2269      <p id="rfc.section.5.4.p.5">This requirement also improves the load-balancing behavior of clients for replicated servers using the same DNS name and reduces
    22452270         the likelihood of a user's experiencing failure in accessing sites which use that strategy.
    22462271      </p>
    2247       <h2 id="rfc.section.10.5"><a href="#rfc.section.10.5">10.5</a>&nbsp;<a id="attack.proxies" href="#attack.proxies">Proxies and Caching</a></h2>
    2248       <p id="rfc.section.10.5.p.1">By their very nature, HTTP proxies are men-in-the-middle, and represent an opportunity for man-in-the-middle attacks. Compromise
     2272      <h2 id="rfc.section.5.5"><a href="#rfc.section.5.5">5.5</a>&nbsp;<a id="attack.proxies" href="#attack.proxies">Proxies and Caching</a></h2>
     2273      <p id="rfc.section.5.5.p.1">By their very nature, HTTP proxies are men-in-the-middle, and represent an opportunity for man-in-the-middle attacks. Compromise
    22492274         of the systems on which the proxies run can result in serious security and privacy problems. Proxies have access to security-related
    22502275         information, personal information about individual users and organizations, and proprietary information belonging to users
     
    22522277         might be used in the commission of a wide range of potential attacks.
    22532278      </p>
    2254       <p id="rfc.section.10.5.p.2">Proxy operators should protect the systems on which proxies run as they would protect any system that contains or transports
     2279      <p id="rfc.section.5.5.p.2">Proxy operators should protect the systems on which proxies run as they would protect any system that contains or transports
    22552280         sensitive information. In particular, log information gathered at proxies often contains highly sensitive personal information,
    22562281         and/or information about organizations. Log information should be carefully guarded, and appropriate guidelines for use developed
    2257          and followed. (<a href="#abuse.of.server.log.information" title="Abuse of Server Log Information">Section&nbsp;10.2</a>).
    2258       </p>
    2259       <p id="rfc.section.10.5.p.3">Proxy implementors should consider the privacy and security implications of their design and coding decisions, and of the
     2282         and followed. (<a href="#abuse.of.server.log.information" title="Abuse of Server Log Information">Section&nbsp;5.2</a>).
     2283      </p>
     2284      <p id="rfc.section.5.5.p.3">Proxy implementors should consider the privacy and security implications of their design and coding decisions, and of the
    22602285         configuration options they provide to proxy operators (especially the default configuration).
    22612286      </p>
    2262       <p id="rfc.section.10.5.p.4">Users of a proxy need to be aware that they are no trustworthier than the people who run the proxy; HTTP itself cannot solve
     2287      <p id="rfc.section.5.5.p.4">Users of a proxy need to be aware that they are no trustworthier than the people who run the proxy; HTTP itself cannot solve
    22632288         this problem.
    22642289      </p>
    2265       <p id="rfc.section.10.5.p.5">The judicious use of cryptography, when appropriate, may suffice to protect against a broad range of security and privacy
     2290      <p id="rfc.section.5.5.p.5">The judicious use of cryptography, when appropriate, may suffice to protect against a broad range of security and privacy
    22662291         attacks. Such cryptography is beyond the scope of the HTTP/1.1 specification.
    22672292      </p>
    2268       <h2 id="rfc.section.10.6"><a href="#rfc.section.10.6">10.6</a>&nbsp;<a id="attack.DoS" href="#attack.DoS">Denial of Service Attacks on Proxies</a></h2>
    2269       <p id="rfc.section.10.6.p.1">They exist. They are hard to defend against. Research continues. Beware.</p>
    2270       <h1 id="rfc.section.11"><a href="#rfc.section.11">11.</a>&nbsp;<a id="ack" href="#ack">Acknowledgments</a></h1>
    2271       <p id="rfc.section.11.p.1">HTTP has evolved considerably over the years. It has benefited from a large and active developer community--the many people
     2293      <h2 id="rfc.section.5.6"><a href="#rfc.section.5.6">5.6</a>&nbsp;<a id="attack.DoS" href="#attack.DoS">Denial of Service Attacks on Proxies</a></h2>
     2294      <p id="rfc.section.5.6.p.1">They exist. They are hard to defend against. Research continues. Beware.</p>
     2295      <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a id="ack" href="#ack">Acknowledgments</a></h1>
     2296      <p id="rfc.section.6.p.1">HTTP has evolved considerably over the years. It has benefited from a large and active developer community--the many people
    22722297         who have participated on the www-talk mailing list--and it is that community which has been most responsible for the success
    22732298         of HTTP and of the World-Wide Web in general. Marc Andreessen, Robert Cailliau, Daniel W. Connolly, Bob Denny, John Franks,
     
    22752300         and Marc VanHeyningen deserve special recognition for their efforts in defining early aspects of the protocol.
    22762301      </p>
    2277       <p id="rfc.section.11.p.2">This document has benefited greatly from the comments of all those participating in the HTTP-WG. In addition to those already
     2302      <p id="rfc.section.6.p.2">This document has benefited greatly from the comments of all those participating in the HTTP-WG. In addition to those already
    22782303         mentioned, the following individuals have contributed to this specification:
    22792304      </p>
    2280       <p id="rfc.section.11.p.3">Gary Adams, Harald Tveit Alvestrand, Keith Ball, Brian Behlendorf, Paul Burchard, Maurizio Codogno, Mike Cowlishaw, Roman
     2305      <p id="rfc.section.6.p.3">Gary Adams, Harald Tveit Alvestrand, Keith Ball, Brian Behlendorf, Paul Burchard, Maurizio Codogno, Mike Cowlishaw, Roman
    22812306         Czyborra, Michael A. Dolan, Daniel DuBois, David J. Fiander, Alan Freier, Marc Hedlund, Greg Herlihy, Koen Holtman, Alex Hopmann,
    22822307         Bob Jernigan, Shel Kaphan, Rohit Khare, John Klensin, Martijn Koster, Alexei Kosut, David M. Kristol, Daniel LaLiberte, Ben
     
    22862311         Weinman, Francois Yergeau, Mary Ellen Zurko, Josh Cohen.
    22872312      </p>
    2288       <p id="rfc.section.11.p.4">Thanks to the "cave men" of Palo Alto. You know who you are.</p>
    2289       <p id="rfc.section.11.p.5">Jim Gettys (the editor of <a href="#RFC2616" id="rfc.xref.RFC2616.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>) wishes particularly to thank Roy Fielding, the editor of <a href="#RFC2068" id="rfc.xref.RFC2068.4"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a>, along with John Klensin, Jeff Mogul, Paul Leach, Dave Kristol, Koen Holtman, John Franks, Josh Cohen, Alex Hopmann, Scott
     2313      <p id="rfc.section.6.p.4">Thanks to the "cave men" of Palo Alto. You know who you are.</p>
     2314      <p id="rfc.section.6.p.5">Jim Gettys (the editor of <a href="#RFC2616" id="rfc.xref.RFC2616.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>) wishes particularly to thank Roy Fielding, the editor of <a href="#RFC2068" id="rfc.xref.RFC2068.4"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a>, along with John Klensin, Jeff Mogul, Paul Leach, Dave Kristol, Koen Holtman, John Franks, Josh Cohen, Alex Hopmann, Scott
    22902315         Lawrence, and Larry Masinter for their help. And thanks go particularly to Jeff Mogul and Scott Lawrence for performing the
    22912316         "MUST/MAY/SHOULD" audit.
    22922317      </p>
    2293       <p id="rfc.section.11.p.6">The Apache Group, Anselm Baird-Smith, author of Jigsaw, and Henrik Frystyk implemented RFC 2068 early, and we wish to thank
     2318      <p id="rfc.section.6.p.6">The Apache Group, Anselm Baird-Smith, author of Jigsaw, and Henrik Frystyk implemented RFC 2068 early, and we wish to thank
    22942319         them for the discovery of many of the problems that this document attempts to rectify.
    22952320      </p>
    2296       <p id="rfc.section.11.p.7">This specification makes heavy use of the augmented BNF and generic constructs defined by David H. Crocker for <a href="#RFC5234" id="rfc.xref.RFC5234.4"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>. Similarly, it reuses many of the definitions provided by Nathaniel Borenstein and Ned Freed for MIME <a href="#RFC2045" id="rfc.xref.RFC2045.3"><cite title="Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies">[RFC2045]</cite></a>. We hope that their inclusion in this specification will help reduce past confusion over the relationship between HTTP and
     2321      <p id="rfc.section.6.p.7">This specification makes heavy use of the augmented BNF and generic constructs defined by David H. Crocker for <a href="#RFC5234" id="rfc.xref.RFC5234.4"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>. Similarly, it reuses many of the definitions provided by Nathaniel Borenstein and Ned Freed for MIME <a href="#RFC2045" id="rfc.xref.RFC2045.3"><cite title="Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies">[RFC2045]</cite></a>. We hope that their inclusion in this specification will help reduce past confusion over the relationship between HTTP and
    22972322         Internet mail message formats.
    22982323      </p>
    2299       <h1 id="rfc.references"><a id="rfc.section.12" href="#rfc.section.12">12.</a> References
     2324      <h1 id="rfc.references"><a id="rfc.section.7" href="#rfc.section.7">7.</a> References
    23002325      </h1>
    2301       <h2 id="rfc.references.1"><a href="#rfc.section.12.1" id="rfc.section.12.1">12.1</a> Normative References
     2326      <h2 id="rfc.references.1"><a href="#rfc.section.7.1" id="rfc.section.7.1">7.1</a> Normative References
    23022327      </h2>
    23032328      <table summary="Normative References">                 
     
    23462371         </tr>
    23472372      </table>
    2348       <h2 id="rfc.references.2"><a href="#rfc.section.12.2" id="rfc.section.12.2">12.2</a> Informative References
     2373      <h2 id="rfc.references.2"><a href="#rfc.section.7.2" id="rfc.section.7.2">7.2</a> Informative References
    23492374      </h2>
    23502375      <table summary="Informative References">                                         
     
    25322557      <p id="rfc.section.B.1.p.1">This section summarizes major differences between versions HTTP/1.0 and HTTP/1.1.</p>
    25332558      <h3 id="rfc.section.B.1.1"><a href="#rfc.section.B.1.1">B.1.1</a>&nbsp;<a id="changes.to.simplify.multi-homed.web.servers.and.conserve.ip.addresses" href="#changes.to.simplify.multi-homed.web.servers.and.conserve.ip.addresses">Changes to Simplify Multi-homed Web Servers and Conserve IP Addresses</a></h3>
    2534       <p id="rfc.section.B.1.1.p.1">The requirements that clients and servers support the Host request-header, report an error if the Host request-header (<a href="#header.host" id="rfc.xref.header.host.2" title="Host">Section&nbsp;8.4</a>) is missing from an HTTP/1.1 request, and accept absolute URIs (<a href="#request-target" title="request-target">Section&nbsp;4.1.2</a>) are among the most important changes defined by this specification.
     2559      <p id="rfc.section.B.1.1.p.1">The requirements that clients and servers support the Host request-header, report an error if the Host request-header (<a href="#header.host" id="rfc.xref.header.host.2" title="Host">Section&nbsp;3.4</a>) is missing from an HTTP/1.1 request, and accept absolute URIs (<a href="#request-target" title="request-target">Section&nbsp;2.8.1.2</a>) are among the most important changes defined by this specification.
    25352560      </p>
    25362561      <p id="rfc.section.B.1.1.p.2">Older HTTP/1.0 clients assumed a one-to-one relationship of IP addresses and servers; there was no other established mechanism
     
    25652590         Therefore, we need some other mechanism for indicating a persistent connection is desired, which is safe to use even when
    25662591         talking to an old proxy that ignores Connection. Persistent connections are the default for HTTP/1.1 messages; we introduce
    2567          a new keyword (Connection: close) for declaring non-persistence. See <a href="#header.connection" id="rfc.xref.header.connection.7" title="Connection">Section&nbsp;8.1</a>.
     2592         a new keyword (Connection: close) for declaring non-persistence. See <a href="#header.connection" id="rfc.xref.header.connection.7" title="Connection">Section&nbsp;3.1</a>.
    25682593      </p>
    25692594      <p id="rfc.section.B.2.p.3">The original HTTP/1.0 form of persistent connections (the Connection: Keep-Alive and Keep-Alive header) is documented in <a href="http://tools.ietf.org/html/rfc2068#section-19.7.1">Section 19.7.1</a> of <a href="#RFC2068" id="rfc.xref.RFC2068.6"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a>.
     
    25752600      <p id="rfc.section.B.3.p.2">Transfer-coding and message lengths all interact in ways that required fixing exactly when chunked encoding is used (to allow
    25762601         for transfer encoding that may not be self delimiting); it was important to straighten out exactly how message lengths are
    2577          computed. (Sections <a href="#transfer.codings" title="Transfer Codings">6.2</a>, <a href="#message.length" title="Message Length">3.4</a>, <a href="#header.content-length" id="rfc.xref.header.content-length.3" title="Content-Length">8.2</a>, see also <a href="#Part3" id="rfc.xref.Part3.11"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>, <a href="#Part5" id="rfc.xref.Part5.1"><cite title="HTTP/1.1, part 5: Range Requests and Partial Responses">[Part5]</cite></a> and <a href="#Part6" id="rfc.xref.Part6.8"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>)
     2602         computed. (Sections <a href="#transfer.codings" title="Transfer Codings">2.10.2</a>, <a href="#message.length" title="Message Length">2.7.4</a>, <a href="#header.content-length" id="rfc.xref.header.content-length.3" title="Content-Length">3.2</a>, see also <a href="#Part3" id="rfc.xref.Part3.11"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>, <a href="#Part5" id="rfc.xref.Part5.1"><cite title="HTTP/1.1, part 5: Range Requests and Partial Responses">[Part5]</cite></a> and <a href="#Part6" id="rfc.xref.Part6.8"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>)
    25782603      </p>
    25792604      <p id="rfc.section.B.3.p.3">The use and interpretation of HTTP version numbers has been clarified by <a href="#RFC2145" id="rfc.xref.RFC2145.3"><cite title="Use and Interpretation of HTTP Version Numbers">[RFC2145]</cite></a>. Require proxies to upgrade requests to highest protocol version they support to deal with problems discovered in HTTP/1.0
    25802605         implementations (<a href="#http.version" title="HTTP Version">Section&nbsp;2.5</a>)
    25812606      </p>
    2582       <p id="rfc.section.B.3.p.4">Quality Values of zero should indicate that "I don't want something" to allow clients to refuse a representation. (<a href="#quality.values" title="Quality Values">Section&nbsp;6.4</a>)
     2607      <p id="rfc.section.B.3.p.4">Quality Values of zero should indicate that "I don't want something" to allow clients to refuse a representation. (<a href="#quality.values" title="Quality Values">Section&nbsp;2.10.4</a>)
    25832608      </p>
    25842609      <p id="rfc.section.B.3.p.5">Transfer-coding had significant problems, particularly with interactions with chunked encoding. The solution is that transfer-codings
     
    25862611         codings), a new header field (TE) and enabling trailer headers in the future. Transfer encoding is a major performance benefit,
    25872612         so it was worth fixing <a href="#Nie1997" id="rfc.xref.Nie1997.2"><cite title="Network Performance Effects of HTTP/1.1, CSS1, and PNG">[Nie1997]</cite></a>. TE also solves another, obscure, downward interoperability problem that could have occurred due to interactions between
    2588          authentication trailers, chunked encoding and HTTP/1.0 clients.(Section <a href="#transfer.codings" title="Transfer Codings">6.2</a>, <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">6.2.1</a>, and <a href="#header.te" id="rfc.xref.header.te.5" title="TE">8.5</a>)
     2613         authentication trailers, chunked encoding and HTTP/1.0 clients.(Section <a href="#transfer.codings" title="Transfer Codings">2.10.2</a>, <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">2.10.2.1</a>, and <a href="#header.te" id="rfc.xref.header.te.5" title="TE">3.5</a>)
    25892614      </p>
    25902615      <h2 id="rfc.section.B.4"><a href="#rfc.section.B.4">B.4</a>&nbsp;<a id="changes.from.rfc.2616" href="#changes.from.rfc.2616">Changes from RFC 2616</a></h2>
     
    25982623      <p id="rfc.section.B.4.p.3">Clarify that HTTP-Version is case sensitive. (<a href="#http.version" title="HTTP Version">Section&nbsp;2.5</a>)
    25992624      </p>
    2600       <p id="rfc.section.B.4.p.4">Remove reference to non-existant identity transfer-coding value tokens. (Sections <a href="#transfer.codings" title="Transfer Codings">6.2</a> and <a href="#message.length" title="Message Length">3.4</a>)
    2601       </p>
    2602       <p id="rfc.section.B.4.p.5">Clarification that the chunk length does not include the count of the octets in the chunk header and trailer. (<a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;6.2.1</a>)
    2603       </p>
    2604       <p id="rfc.section.B.4.p.6">Require that invalid whitespace around field-names be rejected. (<a href="#header.fields" title="Header Fields">Section&nbsp;3.2</a>)
    2605       </p>
    2606       <p id="rfc.section.B.4.p.7">Update use of abs_path production from RFC1808 to the path-absolute + query components of RFC3986. (<a href="#request-target" title="request-target">Section&nbsp;4.1.2</a>)
    2607       </p>
    2608       <p id="rfc.section.B.4.p.8">Clarify exactly when close connection options must be sent. (<a href="#header.connection" id="rfc.xref.header.connection.8" title="Connection">Section&nbsp;8.1</a>)
     2625      <p id="rfc.section.B.4.p.4">Remove reference to non-existant identity transfer-coding value tokens. (Sections <a href="#transfer.codings" title="Transfer Codings">2.10.2</a> and <a href="#message.length" title="Message Length">2.7.4</a>)
     2626      </p>
     2627      <p id="rfc.section.B.4.p.5">Clarification that the chunk length does not include the count of the octets in the chunk header and trailer. (<a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;2.10.2.1</a>)
     2628      </p>
     2629      <p id="rfc.section.B.4.p.6">Require that invalid whitespace around field-names be rejected. (<a href="#header.fields" title="Header Fields">Section&nbsp;2.7.2</a>)
     2630      </p>
     2631      <p id="rfc.section.B.4.p.7">Update use of abs_path production from RFC1808 to the path-absolute + query components of RFC3986. (<a href="#request-target" title="request-target">Section&nbsp;2.8.1.2</a>)
     2632      </p>
     2633      <p id="rfc.section.B.4.p.8">Clarify exactly when close connection options must be sent. (<a href="#header.connection" id="rfc.xref.header.connection.8" title="Connection">Section&nbsp;3.1</a>)
    26092634      </p>
    26102635      <h1 id="rfc.section.C"><a href="#rfc.section.C">C.</a>&nbsp;<a id="terminology" href="#terminology">Terminology</a></h1>
     
    30303055         </li>
    30313056      </ul>
     3057      <p id="rfc.section.E.9.p.2">Partly resolved issues: </p>
     3058      <ul>
     3059         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/148">http://tools.ietf.org/wg/httpbis/trac/ticket/148</a>&gt;: "update IANA requirements wrt Transfer-Coding values" (add the IANA Considerations subsection)
     3060         </li>
     3061      </ul>
    30323062      <h1 id="rfc.index"><a href="#rfc.index">Index</a></h1>
    30333063      <p class="noprint"><a href="#rfc.index.A">A</a> <a href="#rfc.index.C">C</a> <a href="#rfc.index.D">D</a> <a href="#rfc.index.E">E</a> <a href="#rfc.index.G">G</a> <a href="#rfc.index.H">H</a> <a href="#rfc.index.I">I</a> <a href="#rfc.index.K">K</a> <a href="#rfc.index.M">M</a> <a href="#rfc.index.N">N</a> <a href="#rfc.index.O">O</a> <a href="#rfc.index.P">P</a> <a href="#rfc.index.R">R</a> <a href="#rfc.index.S">S</a> <a href="#rfc.index.T">T</a> <a href="#rfc.index.U">U</a> <a href="#rfc.index.V">V</a>
     
    30363066         <ul class="ind">
    30373067            <li class="indline0"><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul class="ind">
    3038                   <li class="indline1">application/http Media Type&nbsp;&nbsp;<a class="iref" href="#rfc.iref.a.1"><b>9.3.2</b></a></li>
     3068                  <li class="indline1">application/http Media Type&nbsp;&nbsp;<a class="iref" href="#rfc.iref.a.1"><b>4.3.2</b></a></li>
    30393069               </ul>
    30403070            </li>
     
    30443074                  <li class="indline1">client&nbsp;&nbsp;<a class="iref" href="#rfc.iref.c.1">2.1</a></li>
    30453075                  <li class="indline1">connection&nbsp;&nbsp;<a class="iref" href="#rfc.iref.c.2">2.1</a></li>
    3046                   <li class="indline1">Connection header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.connection.1">3.5</a>, <a class="iref" href="#rfc.xref.header.connection.2">7.1.2</a>, <a class="iref" href="#rfc.xref.header.connection.3">7.1.3</a>, <a class="iref" href="#rfc.iref.c.5"><b>8.1</b></a>, <a class="iref" href="#rfc.xref.header.connection.4">8.5</a>, <a class="iref" href="#rfc.xref.header.connection.5">8.8</a>, <a class="iref" href="#rfc.xref.header.connection.6">9.1</a>, <a class="iref" href="#rfc.xref.header.connection.7">B.2</a>, <a class="iref" href="#rfc.xref.header.connection.8">B.4</a></li>
     3076                  <li class="indline1">Connection header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.connection.1">2.7.5</a>, <a class="iref" href="#rfc.xref.header.connection.2">2.11.1.2</a>, <a class="iref" href="#rfc.xref.header.connection.3">2.11.1.3</a>, <a class="iref" href="#rfc.iref.c.5"><b>3.1</b></a>, <a class="iref" href="#rfc.xref.header.connection.4">3.5</a>, <a class="iref" href="#rfc.xref.header.connection.5">3.8</a>, <a class="iref" href="#rfc.xref.header.connection.6">4.1</a>, <a class="iref" href="#rfc.xref.header.connection.7">B.2</a>, <a class="iref" href="#rfc.xref.header.connection.8">B.4</a></li>
    30473077                  <li class="indline1">content negotiation&nbsp;&nbsp;<a class="iref" href="#rfc.iref.c.7">C</a></li>
    3048                   <li class="indline1">Content-Length header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.content-length.1">3.4</a>, <a class="iref" href="#rfc.iref.c.6"><b>8.2</b></a>, <a class="iref" href="#rfc.xref.header.content-length.2">9.1</a>, <a class="iref" href="#rfc.xref.header.content-length.3">B.3</a></li>
     3078                  <li class="indline1">Content-Length header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.content-length.1">2.7.4</a>, <a class="iref" href="#rfc.iref.c.6"><b>3.2</b></a>, <a class="iref" href="#rfc.xref.header.content-length.2">4.1</a>, <a class="iref" href="#rfc.xref.header.content-length.3">B.3</a></li>
    30493079               </ul>
    30503080            </li>
    30513081            <li class="indline0"><a id="rfc.index.D" href="#rfc.index.D"><b>D</b></a><ul class="ind">
    3052                   <li class="indline1">Date header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.date.1">3.5</a>, <a class="iref" href="#rfc.iref.d.2"><b>8.3</b></a>, <a class="iref" href="#rfc.xref.header.date.2">9.1</a></li>
     3082                  <li class="indline1">Date header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.date.1">2.7.5</a>, <a class="iref" href="#rfc.iref.d.2"><b>3.3</b></a>, <a class="iref" href="#rfc.xref.header.date.2">4.1</a></li>
    30533083                  <li class="indline1">downstream&nbsp;&nbsp;<a class="iref" href="#rfc.iref.d.1">2.2</a></li>
    30543084               </ul>
     
    30643094                        <li class="indline1"><tt>absolute-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.27"><b>2.6</b></a></li>
    30653095                        <li class="indline1">ALPHA&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.1"><b>1.2</b></a></li>
    3066                         <li class="indline1"><tt>asctime-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.69"><b>6.1</b></a></li>
    3067                         <li class="indline1"><tt>attribute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.73"><b>6.2</b></a></li>
     3096                        <li class="indline1"><tt>asctime-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.69"><b>2.10.1</b></a></li>
     3097                        <li class="indline1"><tt>attribute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.73"><b>2.10.2</b></a></li>
    30683098                        <li class="indline1"><tt>authority</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.28"><b>2.6</b></a></li>
    30693099                        <li class="indline1"><tt>BWS</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.15"><b>1.2.2</b></a></li>
    3070                         <li class="indline1"><tt>chunk</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.78"><b>6.2.1</b></a></li>
    3071                         <li class="indline1"><tt>chunk-data</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.84"><b>6.2.1</b></a></li>
    3072                         <li class="indline1"><tt>chunk-ext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.81"><b>6.2.1</b></a></li>
    3073                         <li class="indline1"><tt>chunk-ext-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.82"><b>6.2.1</b></a></li>
    3074                         <li class="indline1"><tt>chunk-ext-val</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.83"><b>6.2.1</b></a></li>
    3075                         <li class="indline1"><tt>chunk-size</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.79"><b>6.2.1</b></a></li>
    3076                         <li class="indline1"><tt>Chunked-Body</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.77"><b>6.2.1</b></a></li>
    3077                         <li class="indline1"><tt>comment</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.40"><b>3.2</b></a></li>
    3078                         <li class="indline1"><tt>Connection</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.89"><b>8.1</b></a></li>
    3079                         <li class="indline1"><tt>connection-token</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.91"><b>8.1</b></a></li>
    3080                         <li class="indline1"><tt>Connection-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.90"><b>8.1</b></a></li>
    3081                         <li class="indline1"><tt>Content-Length</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.92"><b>8.2</b></a></li>
    3082                         <li class="indline1"><tt>Content-Length-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.93"><b>8.2</b></a></li>
     3100                        <li class="indline1"><tt>chunk</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.78"><b>2.10.2.1</b></a></li>
     3101                        <li class="indline1"><tt>chunk-data</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.84"><b>2.10.2.1</b></a></li>
     3102                        <li class="indline1"><tt>chunk-ext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.81"><b>2.10.2.1</b></a></li>
     3103                        <li class="indline1"><tt>chunk-ext-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.82"><b>2.10.2.1</b></a></li>
     3104                        <li class="indline1"><tt>chunk-ext-val</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.83"><b>2.10.2.1</b></a></li>
     3105                        <li class="indline1"><tt>chunk-size</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.79"><b>2.10.2.1</b></a></li>
     3106                        <li class="indline1"><tt>Chunked-Body</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.77"><b>2.10.2.1</b></a></li>
     3107                        <li class="indline1"><tt>comment</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.40"><b>2.7.2</b></a></li>
     3108                        <li class="indline1"><tt>Connection</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.89"><b>3.1</b></a></li>
     3109                        <li class="indline1"><tt>connection-token</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.91"><b>3.1</b></a></li>
     3110                        <li class="indline1"><tt>Connection-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.90"><b>3.1</b></a></li>
     3111                        <li class="indline1"><tt>Content-Length</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.92"><b>3.2</b></a></li>
     3112                        <li class="indline1"><tt>Content-Length-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.93"><b>3.2</b></a></li>
    30833113                        <li class="indline1">CR&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.2"><b>1.2</b></a></li>
    30843114                        <li class="indline1">CRLF&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.3"><b>1.2</b></a></li>
    3085                         <li class="indline1"><tt>ctext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.41"><b>3.2</b></a></li>
     3115                        <li class="indline1"><tt>ctext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.41"><b>2.7.2</b></a></li>
    30863116                        <li class="indline1">CTL&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.4"><b>1.2</b></a></li>
    3087                         <li class="indline1"><tt>Date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.94"><b>8.3</b></a></li>
    3088                         <li class="indline1"><tt>Date-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.95"><b>8.3</b></a></li>
    3089                         <li class="indline1"><tt>date1</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.56"><b>6.1</b></a></li>
    3090                         <li class="indline1"><tt>date2</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.75"><b>6.2</b></a></li>
    3091                         <li class="indline1"><tt>date3</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.76"><b>6.2</b></a></li>
    3092                         <li class="indline1"><tt>day</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.63"><b>6.1</b></a></li>
    3093                         <li class="indline1"><tt>day-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.61"><b>6.1</b></a></li>
    3094                         <li class="indline1"><tt>day-name-l</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.62"><b>6.1</b></a></li>
     3117                        <li class="indline1"><tt>Date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.94"><b>3.3</b></a></li>
     3118                        <li class="indline1"><tt>Date-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.95"><b>3.3</b></a></li>
     3119                        <li class="indline1"><tt>date1</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.56"><b>2.10.1</b></a></li>
     3120                        <li class="indline1"><tt>date2</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.75"><b>2.10.2</b></a></li>
     3121                        <li class="indline1"><tt>date3</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.76"><b>2.10.2</b></a></li>
     3122                        <li class="indline1"><tt>day</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.63"><b>2.10.1</b></a></li>
     3123                        <li class="indline1"><tt>day-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.61"><b>2.10.1</b></a></li>
     3124                        <li class="indline1"><tt>day-name-l</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.62"><b>2.10.1</b></a></li>
    30953125                        <li class="indline1">DIGIT&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.5"><b>1.2</b></a></li>
    30963126                        <li class="indline1">DQUOTE&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.6"><b>1.2</b></a></li>
    3097                         <li class="indline1"><tt>extension-code</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.52"><b>5.1.1</b></a></li>
    3098                         <li class="indline1"><tt>extension-method</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.47"><b>4.1.1</b></a></li>
    3099                         <li class="indline1"><tt>field-content</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.39"><b>3.2</b></a></li>
    3100                         <li class="indline1"><tt>field-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.37"><b>3.2</b></a></li>
    3101                         <li class="indline1"><tt>field-value</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.38"><b>3.2</b></a></li>
    3102                         <li class="indline1"><tt>general-header</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.43"><b>3.5</b></a></li>
    3103                         <li class="indline1"><tt>GMT</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.66"><b>6.1</b></a></li>
    3104                         <li class="indline1"><tt>header-field</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.36"><b>3.2</b></a></li>
     3127                        <li class="indline1"><tt>extension-code</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.52"><b>2.9.1.1</b></a></li>
     3128                        <li class="indline1"><tt>extension-method</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.47"><b>2.8.1.1</b></a></li>
     3129                        <li class="indline1"><tt>field-content</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.39"><b>2.7.2</b></a></li>
     3130                        <li class="indline1"><tt>field-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.37"><b>2.7.2</b></a></li>
     3131                        <li class="indline1"><tt>field-value</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.38"><b>2.7.2</b></a></li>
     3132                        <li class="indline1"><tt>general-header</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.43"><b>2.7.5</b></a></li>
     3133                        <li class="indline1"><tt>GMT</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.66"><b>2.10.1</b></a></li>
     3134                        <li class="indline1"><tt>header-field</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.36"><b>2.7.2</b></a></li>
    31053135                        <li class="indline1">HEXDIG&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.7"><b>1.2</b></a></li>
    3106                         <li class="indline1"><tt>Host</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.96"><b>8.4</b></a></li>
    3107                         <li class="indline1"><tt>Host-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.97"><b>8.4</b></a></li>
    3108                         <li class="indline1"><tt>hour</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.58"><b>6.1</b></a></li>
    3109                         <li class="indline1"><tt>HTTP-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.54"><b>6.1</b></a></li>
    3110                         <li class="indline1"><tt>HTTP-message</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.35"><b>3</b></a></li>
     3136                        <li class="indline1"><tt>Host</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.96"><b>3.4</b></a></li>
     3137                        <li class="indline1"><tt>Host-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.97"><b>3.4</b></a></li>
     3138                        <li class="indline1"><tt>hour</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.58"><b>2.10.1</b></a></li>
     3139                        <li class="indline1"><tt>HTTP-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.54"><b>2.10.1</b></a></li>
     3140                        <li class="indline1"><tt>HTTP-message</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.35"><b>2.7</b></a></li>
    31113141                        <li class="indline1"><tt>HTTP-Prot-Name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.25"><b>2.5</b></a></li>
    31123142                        <li class="indline1"><tt>http-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.33"><b>2.6.1</b></a></li>
    31133143                        <li class="indline1"><tt>HTTP-Version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.24"><b>2.5</b></a></li>
    31143144                        <li class="indline1"><tt>https-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.34"><b>2.6.2</b></a></li>
    3115                         <li class="indline1"><tt>last-chunk</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.80"><b>6.2.1</b></a></li>
     3145                        <li class="indline1"><tt>last-chunk</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.80"><b>2.10.2.1</b></a></li>
    31163146                        <li class="indline1">LF&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.8"><b>1.2</b></a></li>
    3117                         <li class="indline1"><tt>message-body</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.42"><b>3.3</b></a></li>
    3118                         <li class="indline1"><tt>Method</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.46"><b>4.1.1</b></a></li>
    3119                         <li class="indline1"><tt>minute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.59"><b>6.1</b></a></li>
    3120                         <li class="indline1"><tt>month</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.64"><b>6.1</b></a></li>
    3121                         <li class="indline1"><tt>obs-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.67"><b>6.1</b></a></li>
     3147                        <li class="indline1"><tt>message-body</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.42"><b>2.7.3</b></a></li>
     3148                        <li class="indline1"><tt>Method</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.46"><b>2.8.1.1</b></a></li>
     3149                        <li class="indline1"><tt>minute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.59"><b>2.10.1</b></a></li>
     3150                        <li class="indline1"><tt>month</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.64"><b>2.10.1</b></a></li>
     3151                        <li class="indline1"><tt>obs-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.67"><b>2.10.1</b></a></li>
    31223152                        <li class="indline1"><tt>obs-text</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.20"><b>1.2.2</b></a></li>
    31233153                        <li class="indline1">OCTET&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.9"><b>1.2</b></a></li>
     
    31253155                        <li class="indline1"><tt>path-absolute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.29"><b>2.6</b></a></li>
    31263156                        <li class="indline1"><tt>port</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.30"><b>2.6</b></a></li>
    3127                         <li class="indline1"><tt>product</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.86"><b>6.3</b></a></li>
    3128                         <li class="indline1"><tt>product-version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.87"><b>6.3</b></a></li>
    3129                         <li class="indline1"><tt>protocol-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.112"><b>8.9</b></a></li>
    3130                         <li class="indline1"><tt>protocol-version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.113"><b>8.9</b></a></li>
    3131                         <li class="indline1"><tt>pseudonym</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.115"><b>8.9</b></a></li>
     3157                        <li class="indline1"><tt>product</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.86"><b>2.10.3</b></a></li>
     3158                        <li class="indline1"><tt>product-version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.87"><b>2.10.3</b></a></li>
     3159                        <li class="indline1"><tt>protocol-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.112"><b>3.9</b></a></li>
     3160                        <li class="indline1"><tt>protocol-version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.113"><b>3.9</b></a></li>
     3161                        <li class="indline1"><tt>pseudonym</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.115"><b>3.9</b></a></li>
    31323162                        <li class="indline1"><tt>qdtext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.19"><b>1.2.2</b></a></li>
    31333163                        <li class="indline1"><tt>query</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.31"><b>2.6</b></a></li>
     
    31353165                        <li class="indline1"><tt>quoted-string</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.18"><b>1.2.2</b></a></li>
    31363166                        <li class="indline1"><tt>quoted-text</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.21"><b>1.2.2</b></a></li>
    3137                         <li class="indline1"><tt>qvalue</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.88"><b>6.4</b></a></li>
    3138                         <li class="indline1"><tt>Reason-Phrase</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.53"><b>5.1.1</b></a></li>
    3139                         <li class="indline1"><tt>received-by</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.114"><b>8.9</b></a></li>
    3140                         <li class="indline1"><tt>received-protocol</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.111"><b>8.9</b></a></li>
    3141                         <li class="indline1"><tt>Request</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.44"><b>4</b></a></li>
    3142                         <li class="indline1"><tt>Request-Line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.45"><b>4.1</b></a></li>
    3143                         <li class="indline1"><tt>request-target</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.48"><b>4.1.2</b></a></li>
    3144                         <li class="indline1"><tt>Response</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.49"><b>5</b></a></li>
    3145                         <li class="indline1"><tt>rfc1123-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.55"><b>6.1</b></a></li>
    3146                         <li class="indline1"><tt>rfc850-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.68"><b>6.1</b></a></li>
     3167                        <li class="indline1"><tt>qvalue</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.88"><b>2.10.4</b></a></li>
     3168                        <li class="indline1"><tt>Reason-Phrase</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.53"><b>2.9.1.1</b></a></li>
     3169                        <li class="indline1"><tt>received-by</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.114"><b>3.9</b></a></li>
     3170                        <li class="indline1"><tt>received-protocol</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.111"><b>3.9</b></a></li>
     3171                        <li class="indline1"><tt>Request</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.44"><b>2.8</b></a></li>
     3172                        <li class="indline1"><tt>Request-Line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.45"><b>2.8.1</b></a></li>
     3173                        <li class="indline1"><tt>request-target</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.48"><b>2.8.1.2</b></a></li>
     3174                        <li class="indline1"><tt>Response</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.49"><b>2.9</b></a></li>
     3175                        <li class="indline1"><tt>rfc1123-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.55"><b>2.10.1</b></a></li>
     3176                        <li class="indline1"><tt>rfc850-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.68"><b>2.10.1</b></a></li>
    31473177                        <li class="indline1"><tt>RWS</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.14"><b>1.2.2</b></a></li>
    3148                         <li class="indline1"><tt>second</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.60"><b>6.1</b></a></li>
     3178                        <li class="indline1"><tt>second</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.60"><b>2.10.1</b></a></li>
    31493179                        <li class="indline1">SP&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.10"><b>1.2</b></a></li>
    3150                         <li class="indline1"><tt>Status-Code</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.51"><b>5.1.1</b></a></li>
    3151                         <li class="indline1"><tt>Status-Line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.50"><b>5.1</b></a></li>
    3152                         <li class="indline1"><tt>t-codings</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.100"><b>8.5</b></a></li>
     3180                        <li class="indline1"><tt>Status-Code</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.51"><b>2.9.1.1</b></a></li>
     3181                        <li class="indline1"><tt>Status-Line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.50"><b>2.9.1</b></a></li>
     3182                        <li class="indline1"><tt>t-codings</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.100"><b>3.5</b></a></li>
    31533183                        <li class="indline1"><tt>tchar</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.17"><b>1.2.2</b></a></li>
    3154                         <li class="indline1"><tt>TE</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.98"><b>8.5</b></a></li>
    3155                         <li class="indline1"><tt>te-ext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.102"><b>8.5</b></a></li>
    3156                         <li class="indline1"><tt>te-params</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.101"><b>8.5</b></a></li>
    3157                         <li class="indline1"><tt>TE-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.99"><b>8.5</b></a></li>
    3158                         <li class="indline1"><tt>time-of-day</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.57"><b>6.1</b></a></li>
     3184                        <li class="indline1"><tt>TE</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.98"><b>3.5</b></a></li>
     3185                        <li class="indline1"><tt>te-ext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.102"><b>3.5</b></a></li>
     3186                        <li class="indline1"><tt>te-params</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.101"><b>3.5</b></a></li>
     3187                        <li class="indline1"><tt>TE-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.99"><b>3.5</b></a></li>
     3188                        <li class="indline1"><tt>time-of-day</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.57"><b>2.10.1</b></a></li>
    31593189                        <li class="indline1"><tt>token</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.16"><b>1.2.2</b></a></li>
    3160                         <li class="indline1"><tt>Trailer</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.103"><b>8.6</b></a></li>
    3161                         <li class="indline1"><tt>trailer-part</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.85"><b>6.2.1</b></a></li>
    3162                         <li class="indline1"><tt>Trailer-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.104"><b>8.6</b></a></li>
    3163                         <li class="indline1"><tt>transfer-coding</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.70"><b>6.2</b></a></li>
    3164                         <li class="indline1"><tt>Transfer-Encoding</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.105"><b>8.7</b></a></li>
    3165                         <li class="indline1"><tt>Transfer-Encoding-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.106"><b>8.7</b></a></li>
    3166                         <li class="indline1"><tt>transfer-extension</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.71"><b>6.2</b></a></li>
    3167                         <li class="indline1"><tt>transfer-parameter</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.72"><b>6.2</b></a></li>
    3168                         <li class="indline1"><tt>Upgrade</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.107"><b>8.8</b></a></li>
    3169                         <li class="indline1"><tt>Upgrade-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.108"><b>8.8</b></a></li>
     3190                        <li class="indline1"><tt>Trailer</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.103"><b>3.6</b></a></li>
     3191                        <li class="indline1"><tt>trailer-part</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.85"><b>2.10.2.1</b></a></li>
     3192                        <li class="indline1"><tt>Trailer-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.104"><b>3.6</b></a></li>
     3193                        <li class="indline1"><tt>transfer-coding</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.70"><b>2.10.2</b></a></li>
     3194                        <li class="indline1"><tt>Transfer-Encoding</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.105"><b>3.7</b></a></li>
     3195                        <li class="indline1"><tt>Transfer-Encoding-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.106"><b>3.7</b></a></li>
     3196                        <li class="indline1"><tt>transfer-extension</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.71"><b>2.10.2</b></a></li>
     3197                        <li class="indline1"><tt>transfer-parameter</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.72"><b>2.10.2</b></a></li>
     3198                        <li class="indline1"><tt>Upgrade</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.107"><b>3.8</b></a></li>
     3199                        <li class="indline1"><tt>Upgrade-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.108"><b>3.8</b></a></li>
    31703200                        <li class="indline1"><tt>uri-host</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.32"><b>2.6</b></a></li>
    31713201                        <li class="indline1"><tt>URI-reference</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.26"><b>2.6</b></a></li>
    3172                         <li class="indline1"><tt>value</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.74"><b>6.2</b></a></li>
     3202                        <li class="indline1"><tt>value</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.74"><b>2.10.2</b></a></li>
    31733203                        <li class="indline1">VCHAR&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.11"><b>1.2</b></a></li>
    3174                         <li class="indline1"><tt>Via</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.109"><b>8.9</b></a></li>
    3175                         <li class="indline1"><tt>Via-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.110"><b>8.9</b></a></li>
     3204                        <li class="indline1"><tt>Via</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.109"><b>3.9</b></a></li>
     3205                        <li class="indline1"><tt>Via-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.110"><b>3.9</b></a></li>
    31763206                        <li class="indline1">WSP&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.12"><b>1.2</b></a></li>
    3177                         <li class="indline1"><tt>year</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.65"><b>6.1</b></a></li>
     3207                        <li class="indline1"><tt>year</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.65"><b>2.10.1</b></a></li>
    31783208                     </ul>
    31793209                  </li>
     
    31813211            </li>
    31823212            <li class="indline0"><a id="rfc.index.H" href="#rfc.index.H"><b>H</b></a><ul class="ind">
    3183                   <li class="indline1">header field&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.5">3</a></li>
    3184                   <li class="indline1">header section&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.3">3</a></li>
    3185                   <li class="indline1">headers&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.4">3</a></li>
     3213                  <li class="indline1">header field&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.5">2.7</a></li>
     3214                  <li class="indline1">header section&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.3">2.7</a></li>
     3215                  <li class="indline1">headers&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.4">2.7</a></li>
    31863216                  <li class="indline1">Headers&nbsp;&nbsp;
    31873217                     <ul class="ind">
    3188                         <li class="indline1">Connection&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.connection.1">3.5</a>, <a class="iref" href="#rfc.xref.header.connection.2">7.1.2</a>, <a class="iref" href="#rfc.xref.header.connection.3">7.1.3</a>, <a class="iref" href="#rfc.iref.h.6"><b>8.1</b></a>, <a class="iref" href="#rfc.xref.header.connection.4">8.5</a>, <a class="iref" href="#rfc.xref.header.connection.5">8.8</a>, <a class="iref" href="#rfc.xref.header.connection.6">9.1</a>, <a class="iref" href="#rfc.xref.header.connection.7">B.2</a>, <a class="iref" href="#rfc.xref.header.connection.8">B.4</a></li>
    3189                         <li class="indline1">Content-Length&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.content-length.1">3.4</a>, <a class="iref" href="#rfc.iref.h.7"><b>8.2</b></a>, <a class="iref" href="#rfc.xref.header.content-length.2">9.1</a>, <a class="iref" href="#rfc.xref.header.content-length.3">B.3</a></li>
    3190                         <li class="indline1">Date&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.date.1">3.5</a>, <a class="iref" href="#rfc.iref.h.8"><b>8.3</b></a>, <a class="iref" href="#rfc.xref.header.date.2">9.1</a></li>
    3191                         <li class="indline1">Host&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.10"><b>8.4</b></a>, <a class="iref" href="#rfc.xref.header.host.1">9.1</a>, <a class="iref" href="#rfc.xref.header.host.2">B.1.1</a></li>
    3192                         <li class="indline1">TE&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.te.1">6.2</a>, <a class="iref" href="#rfc.xref.header.te.2">6.2.1</a>, <a class="iref" href="#rfc.xref.header.te.3">6.4</a>, <a class="iref" href="#rfc.iref.h.11"><b>8.5</b></a>, <a class="iref" href="#rfc.xref.header.te.4">9.1</a>, <a class="iref" href="#rfc.xref.header.te.5">B.3</a></li>
    3193                         <li class="indline1">Trailer&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.trailer.1">3.5</a>, <a class="iref" href="#rfc.xref.header.trailer.2">6.2.1</a>, <a class="iref" href="#rfc.iref.h.12"><b>8.6</b></a>, <a class="iref" href="#rfc.xref.header.trailer.3">9.1</a></li>
    3194                         <li class="indline1">Transfer-Encoding&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.transfer-encoding.1">3.3</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.2">3.4</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.3">3.5</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.4">6.2</a>, <a class="iref" href="#rfc.iref.h.13"><b>8.7</b></a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.5">9.1</a></li>
    3195                         <li class="indline1">Upgrade&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.upgrade.1">3.5</a>, <a class="iref" href="#rfc.iref.h.14"><b>8.8</b></a>, <a class="iref" href="#rfc.xref.header.upgrade.2">9.1</a></li>
    3196                         <li class="indline1">Via&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.via.1">3.5</a>, <a class="iref" href="#rfc.iref.h.15"><b>8.9</b></a>, <a class="iref" href="#rfc.xref.header.via.2">9.1</a></li>
     3218                        <li class="indline1">Connection&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.connection.1">2.7.5</a>, <a class="iref" href="#rfc.xref.header.connection.2">2.11.1.2</a>, <a class="iref" href="#rfc.xref.header.connection.3">2.11.1.3</a>, <a class="iref" href="#rfc.iref.h.6"><b>3.1</b></a>, <a class="iref" href="#rfc.xref.header.connection.4">3.5</a>, <a class="iref" href="#rfc.xref.header.connection.5">3.8</a>, <a class="iref" href="#rfc.xref.header.connection.6">4.1</a>, <a class="iref" href="#rfc.xref.header.connection.7">B.2</a>, <a class="iref" href="#rfc.xref.header.connection.8">B.4</a></li>
     3219                        <li class="indline1">Content-Length&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.content-length.1">2.7.4</a>, <a class="iref" href="#rfc.iref.h.7"><b>3.2</b></a>, <a class="iref" href="#rfc.xref.header.content-length.2">4.1</a>, <a class="iref" href="#rfc.xref.header.content-length.3">B.3</a></li>
     3220                        <li class="indline1">Date&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.date.1">2.7.5</a>, <a class="iref" href="#rfc.iref.h.8"><b>3.3</b></a>, <a class="iref" href="#rfc.xref.header.date.2">4.1</a></li>
     3221                        <li class="indline1">Host&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.10"><b>3.4</b></a>, <a class="iref" href="#rfc.xref.header.host.1">4.1</a>, <a class="iref" href="#rfc.xref.header.host.2">B.1.1</a></li>
     3222                        <li class="indline1">TE&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.te.1">2.10.2</a>, <a class="iref" href="#rfc.xref.header.te.2">2.10.2.1</a>, <a class="iref" href="#rfc.xref.header.te.3">2.10.4</a>, <a class="iref" href="#rfc.iref.h.11"><b>3.5</b></a>, <a class="iref" href="#rfc.xref.header.te.4">4.1</a>, <a class="iref" href="#rfc.xref.header.te.5">B.3</a></li>
     3223                        <li class="indline1">Trailer&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.trailer.1">2.7.5</a>, <a class="iref" href="#rfc.xref.header.trailer.2">2.10.2.1</a>, <a class="iref" href="#rfc.iref.h.12"><b>3.6</b></a>, <a class="iref" href="#rfc.xref.header.trailer.3">4.1</a></li>
     3224                        <li class="indline1">Transfer-Encoding&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.transfer-encoding.1">2.7.3</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.2">2.7.4</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.3">2.7.5</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.4">2.10.2</a>, <a class="iref" href="#rfc.iref.h.13"><b>3.7</b></a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.5">4.1</a></li>
     3225                        <li class="indline1">Upgrade&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.upgrade.1">2.7.5</a>, <a class="iref" href="#rfc.iref.h.14"><b>3.8</b></a>, <a class="iref" href="#rfc.xref.header.upgrade.2">4.1</a></li>
     3226                        <li class="indline1">Via&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.via.1">2.7.5</a>, <a class="iref" href="#rfc.iref.h.15"><b>3.9</b></a>, <a class="iref" href="#rfc.xref.header.via.2">4.1</a></li>
    31973227                     </ul>
    31983228                  </li>
    3199                   <li class="indline1">Host header&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.9"><b>8.4</b></a>, <a class="iref" href="#rfc.xref.header.host.1">9.1</a>, <a class="iref" href="#rfc.xref.header.host.2">B.1.1</a></li>
     3229                  <li class="indline1">Host header&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.9"><b>3.4</b></a>, <a class="iref" href="#rfc.xref.header.host.1">4.1</a>, <a class="iref" href="#rfc.xref.header.host.2">B.1.1</a></li>
    32003230                  <li class="indline1">http URI scheme&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.1"><b>2.6.1</b></a></li>
    32013231                  <li class="indline1">https URI scheme&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.2">2.6.2</a></li>
     
    32043234            <li class="indline0"><a id="rfc.index.I" href="#rfc.index.I"><b>I</b></a><ul class="ind">
    32053235                  <li class="indline1">inbound&nbsp;&nbsp;<a class="iref" href="#rfc.iref.i.1">2.2</a></li>
    3206                   <li class="indline1"><em>ISO-8859-1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.ISO-8859-1.1">3.2</a>, <a class="iref" href="#ISO-8859-1"><b>12.1</b></a></li>
     3236                  <li class="indline1"><em>ISO-8859-1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.ISO-8859-1.1">2.7.2</a>, <a class="iref" href="#ISO-8859-1"><b>7.1</b></a></li>
    32073237               </ul>
    32083238            </li>
    32093239            <li class="indline0"><a id="rfc.index.K" href="#rfc.index.K"><b>K</b></a><ul class="ind">
    3210                   <li class="indline1"><em>Kri2001</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Kri2001.1">3.2</a>, <a class="iref" href="#Kri2001"><b>12.2</b></a></li>
     3240                  <li class="indline1"><em>Kri2001</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Kri2001.1">2.7.2</a>, <a class="iref" href="#Kri2001"><b>7.2</b></a></li>
    32113241               </ul>
    32123242            </li>
     
    32143244                  <li class="indline1">Media Type&nbsp;&nbsp;
    32153245                     <ul class="ind">
    3216                         <li class="indline1">application/http&nbsp;&nbsp;<a class="iref" href="#rfc.iref.m.4"><b>9.3.2</b></a></li>
    3217                         <li class="indline1">message/http&nbsp;&nbsp;<a class="iref" href="#rfc.iref.m.2"><b>9.3.1</b></a></li>
     3246                        <li class="indline1">application/http&nbsp;&nbsp;<a class="iref" href="#rfc.iref.m.4"><b>4.3.2</b></a></li>
     3247                        <li class="indline1">message/http&nbsp;&nbsp;<a class="iref" href="#rfc.iref.m.2"><b>4.3.1</b></a></li>
    32183248                     </ul>
    32193249                  </li>
    32203250                  <li class="indline1">message&nbsp;&nbsp;<a class="iref" href="#rfc.iref.m.1">2.1</a></li>
    3221                   <li class="indline1">message/http Media Type&nbsp;&nbsp;<a class="iref" href="#rfc.iref.m.3"><b>9.3.1</b></a></li>
     3251                  <li class="indline1">message/http Media Type&nbsp;&nbsp;<a class="iref" href="#rfc.iref.m.3"><b>4.3.1</b></a></li>
    32223252               </ul>
    32233253            </li>
    32243254            <li class="indline0"><a id="rfc.index.N" href="#rfc.index.N"><b>N</b></a><ul class="ind">
    3225                   <li class="indline1"><em>Nie1997</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Nie1997.1">7.1.1</a>, <a class="iref" href="#Nie1997"><b>12.2</b></a>, <a class="iref" href="#rfc.xref.Nie1997.2">B.3</a></li>
     3255                  <li class="indline1"><em>Nie1997</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Nie1997.1">2.11.1.1</a>, <a class="iref" href="#Nie1997"><b>7.2</b></a>, <a class="iref" href="#rfc.xref.Nie1997.2">B.3</a></li>
    32263256               </ul>
    32273257            </li>
     
    32323262            </li>
    32333263            <li class="indline0"><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul class="ind">
    3234                   <li class="indline1"><em>Pad1995</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Pad1995.1">7.1.1</a>, <a class="iref" href="#Pad1995"><b>12.2</b></a></li>
    3235                   <li class="indline1"><em>Part2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.1">1.2.3</a>, <a class="iref" href="#rfc.xref.Part2.2">1.2.3</a>, <a class="iref" href="#rfc.xref.Part2.3">4</a>, <a class="iref" href="#rfc.xref.Part2.4">4.1.2</a>, <a class="iref" href="#rfc.xref.Part2.5">4.1.2</a>, <a class="iref" href="#rfc.xref.Part2.6">5</a>, <a class="iref" href="#rfc.xref.Part2.7">5.1.1</a>, <a class="iref" href="#rfc.xref.Part2.8">7.1.2.2</a>, <a class="iref" href="#rfc.xref.Part2.9">7.1.4</a>, <a class="iref" href="#rfc.xref.Part2.10">7.2.3</a>, <a class="iref" href="#rfc.xref.Part2.11">7.2.3</a>, <a class="iref" href="#rfc.xref.Part2.12">7.2.3</a>, <a class="iref" href="#rfc.xref.Part2.13">7.2.3</a>, <a class="iref" href="#Part2"><b>12.1</b></a><ul class="ind">
    3236                         <li class="indline1"><em>Section 3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.1">1.2.3</a>, <a class="iref" href="#rfc.xref.Part2.3">4</a></li>
    3237                         <li class="indline1"><em>Section 5</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.2">1.2.3</a>, <a class="iref" href="#rfc.xref.Part2.6">5</a></li>
    3238                         <li class="indline1"><em>Section 7.1.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.8">7.1.2.2</a>, <a class="iref" href="#rfc.xref.Part2.9">7.1.4</a></li>
    3239                         <li class="indline1"><em>Section 7.9</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.4">4.1.2</a></li>
    3240                         <li class="indline1"><em>Section 8</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.7">5.1.1</a></li>
    3241                         <li class="indline1"><em>Section 8.1.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.10">7.2.3</a></li>
    3242                         <li class="indline1"><em>Section 8.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.13">7.2.3</a></li>
    3243                         <li class="indline1"><em>Section 8.4.15</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.5">4.1.2</a></li>
    3244                         <li class="indline1"><em>Section 9.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.11">7.2.3</a>, <a class="iref" href="#rfc.xref.Part2.12">7.2.3</a></li>
     3264                  <li class="indline1"><em>Pad1995</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Pad1995.1">2.11.1.1</a>, <a class="iref" href="#Pad1995"><b>7.2</b></a></li>
     3265                  <li class="indline1"><em>Part2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.1">1.2.3</a>, <a class="iref" href="#rfc.xref.Part2.2">1.2.3</a>, <a class="iref" href="#rfc.xref.Part2.3">2.8</a>, <a class="iref" href="#rfc.xref.Part2.4">2.8.1.2</a>, <a class="iref" href="#rfc.xref.Part2.5">2.8.1.2</a>, <a class="iref" href="#rfc.xref.Part2.6">2.9</a>, <a class="iref" href="#rfc.xref.Part2.7">2.9.1.1</a>, <a class="iref" href="#rfc.xref.Part2.8">2.11.1.2.2</a>, <a class="iref" href="#rfc.xref.Part2.9">2.11.1.4</a>, <a class="iref" href="#rfc.xref.Part2.10">2.11.2.3</a>, <a class="iref" href="#rfc.xref.Part2.11">2.11.2.3</a>, <a class="iref" href="#rfc.xref.Part2.12">2.11.2.3</a>, <a class="iref" href="#rfc.xref.Part2.13">2.11.2.3</a>, <a class="iref" href="#Part2"><b>7.1</b></a><ul class="ind">
     3266                        <li class="indline1"><em>Section 3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.1">1.2.3</a>, <a class="iref" href="#rfc.xref.Part2.3">2.8</a></li>
     3267                        <li class="indline1"><em>Section 5</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.2">1.2.3</a>, <a class="iref" href="#rfc.xref.Part2.6">2.9</a></li>
     3268                        <li class="indline1"><em>Section 7.1.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.8">2.11.1.2.2</a>, <a class="iref" href="#rfc.xref.Part2.9">2.11.1.4</a></li>
     3269                        <li class="indline1"><em>Section 7.9</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.4">2.8.1.2</a></li>
     3270                        <li class="indline1"><em>Section 8</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.7">2.9.1.1</a></li>
     3271                        <li class="indline1"><em>Section 8.1.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.10">2.11.2.3</a></li>
     3272                        <li class="indline1"><em>Section 8.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.13">2.11.2.3</a></li>
     3273                        <li class="indline1"><em>Section 8.4.15</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.5">2.8.1.2</a></li>
     3274                        <li class="indline1"><em>Section 9.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.11">2.11.2.3</a>, <a class="iref" href="#rfc.xref.Part2.12">2.11.2.3</a></li>
    32453275                     </ul>
    32463276                  </li>
    3247                   <li class="indline1"><em>Part3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.1">1</a>, <a class="iref" href="#rfc.xref.Part3.2">1.2.2</a>, <a class="iref" href="#rfc.xref.Part3.3">1.2.3</a>, <a class="iref" href="#rfc.xref.Part3.4">1.2.3</a>, <a class="iref" href="#rfc.xref.Part3.5">4</a>, <a class="iref" href="#rfc.xref.Part3.6">5</a>, <a class="iref" href="#rfc.xref.Part3.7">6.2</a>, <a class="iref" href="#rfc.xref.Part3.8">6.2</a>, <a class="iref" href="#rfc.xref.Part3.9">6.4</a>, <a class="iref" href="#Part3"><b>12.1</b></a>, <a class="iref" href="#rfc.xref.Part3.10">A</a>, <a class="iref" href="#rfc.xref.Part3.11">B.3</a>, <a class="iref" href="#rfc.xref.Part3.12">C</a>, <a class="iref" href="#rfc.xref.Part3.13">C</a>, <a class="iref" href="#rfc.xref.Part3.14">C</a><ul class="ind">
    3248                         <li class="indline1"><em>Section 2.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.7">6.2</a>, <a class="iref" href="#rfc.xref.Part3.8">6.2</a></li>
     3277                  <li class="indline1"><em>Part3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.1">1</a>, <a class="iref" href="#rfc.xref.Part3.2">1.2.2</a>, <a class="iref" href="#rfc.xref.Part3.3">1.2.3</a>, <a class="iref" href="#rfc.xref.Part3.4">1.2.3</a>, <a class="iref" href="#rfc.xref.Part3.5">2.8</a>, <a class="iref" href="#rfc.xref.Part3.6">2.9</a>, <a class="iref" href="#rfc.xref.Part3.7">2.10.2</a>, <a class="iref" href="#rfc.xref.Part3.8">2.10.2</a>, <a class="iref" href="#rfc.xref.Part3.9">2.10.4</a>, <a class="iref" href="#Part3"><b>7.1</b></a>, <a class="iref" href="#rfc.xref.Part3.10">A</a>, <a class="iref" href="#rfc.xref.Part3.11">B.3</a>, <a class="iref" href="#rfc.xref.Part3.12">C</a>, <a class="iref" href="#rfc.xref.Part3.13">C</a>, <a class="iref" href="#rfc.xref.Part3.14">C</a><ul class="ind">
     3278                        <li class="indline1"><em>Section 2.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.7">2.10.2</a>, <a class="iref" href="#rfc.xref.Part3.8">2.10.2</a></li>
    32493279                        <li class="indline1"><em>Section 2.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.2">1.2.2</a></li>
    3250                         <li class="indline1"><em>Section 3.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.4">1.2.3</a>, <a class="iref" href="#rfc.xref.Part3.5">4</a>, <a class="iref" href="#rfc.xref.Part3.6">5</a></li>
     3280                        <li class="indline1"><em>Section 3.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.4">1.2.3</a>, <a class="iref" href="#rfc.xref.Part3.5">2.8</a>, <a class="iref" href="#rfc.xref.Part3.6">2.9</a></li>
    32513281                        <li class="indline1"><em>Section 3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.13">C</a></li>
    32523282                        <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.3">1.2.3</a></li>
    3253                         <li class="indline1"><em>Section 4</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.9">6.4</a>, <a class="iref" href="#rfc.xref.Part3.12">C</a>, <a class="iref" href="#rfc.xref.Part3.14">C</a></li>
     3283                        <li class="indline1"><em>Section 4</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.9">2.10.4</a>, <a class="iref" href="#rfc.xref.Part3.12">C</a>, <a class="iref" href="#rfc.xref.Part3.14">C</a></li>
    32543284                        <li class="indline1"><em>Appendix A</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.1">1</a></li>
    32553285                     </ul>
    32563286                  </li>
    3257                   <li class="indline1"><em>Part5</em>&nbsp;&nbsp;<a class="iref" href="#Part5"><b>12.1</b></a>, <a class="iref" href="#rfc.xref.Part5.1">B.3</a></li>
    3258                   <li class="indline1"><em>Part6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.1">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.2">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.3">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.4">2.3</a>, <a class="iref" href="#rfc.xref.Part6.5">3.5</a>, <a class="iref" href="#rfc.xref.Part6.6">3.5</a>, <a class="iref" href="#rfc.xref.Part6.7">3.5</a>, <a class="iref" href="#Part6"><b>12.1</b></a>, <a class="iref" href="#rfc.xref.Part6.8">B.3</a><ul class="ind">
     3287                  <li class="indline1"><em>Part5</em>&nbsp;&nbsp;<a class="iref" href="#Part5"><b>7.1</b></a>, <a class="iref" href="#rfc.xref.Part5.1">B.3</a></li>
     3288                  <li class="indline1"><em>Part6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.1">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.2">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.3">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.4">2.3</a>, <a class="iref" href="#rfc.xref.Part6.5">2.7.5</a>, <a class="iref" href="#rfc.xref.Part6.6">2.7.5</a>, <a class="iref" href="#rfc.xref.Part6.7">2.7.5</a>, <a class="iref" href="#Part6"><b>7.1</b></a>, <a class="iref" href="#rfc.xref.Part6.8">B.3</a><ul class="ind">
    32593289                        <li class="indline1"><em>Section 2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.4">2.3</a></li>
    3260                         <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.5">3.5</a></li>
    3261                         <li class="indline1"><em>Section 3.4</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.1">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.2">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.6">3.5</a></li>
    3262                         <li class="indline1"><em>Section 3.6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.3">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.7">3.5</a></li>
     3290                        <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.5">2.7.5</a></li>
     3291                        <li class="indline1"><em>Section 3.4</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.1">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.2">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.6">2.7.5</a></li>
     3292                        <li class="indline1"><em>Section 3.6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.3">1.2.3</a>, <a class="iref" href="#rfc.xref.Part6.7">2.7.5</a></li>
    32633293                     </ul>
    32643294                  </li>
     
    32723302                  <li class="indline1">response&nbsp;&nbsp;<a class="iref" href="#rfc.iref.r.2">2.1</a></li>
    32733303                  <li class="indline1">reverse proxy&nbsp;&nbsp;<a class="iref" href="#rfc.iref.r.3">2.2</a></li>
    3274                   <li class="indline1"><em>RFC1123</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC1123.1">6.1</a>, <a class="iref" href="#RFC1123"><b>12.2</b></a></li>
    3275                   <li class="indline1"><em>RFC1305</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC1305.1">8.3</a>, <a class="iref" href="#RFC1305"><b>12.2</b></a></li>
    3276                   <li class="indline1"><em>RFC1900</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC1900.1">10.4</a>, <a class="iref" href="#RFC1900"><b>12.2</b></a></li>
    3277                   <li class="indline1"><em>RFC1945</em>&nbsp;&nbsp;<a class="iref" href="#RFC1945"><b>12.2</b></a>, <a class="iref" href="#rfc.xref.RFC1945.1">B</a></li>
    3278                   <li class="indline1"><em>RFC2045</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2045.1">1</a>, <a class="iref" href="#rfc.xref.RFC2045.2">6.2</a>, <a class="iref" href="#rfc.xref.RFC2045.3">11</a>, <a class="iref" href="#RFC2045"><b>12.2</b></a><ul class="ind">
    3279                         <li class="indline1"><em>Section 6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2045.2">6.2</a></li>
     3304                  <li class="indline1"><em>RFC1123</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC1123.1">2.10.1</a>, <a class="iref" href="#RFC1123"><b>7.2</b></a></li>
     3305                  <li class="indline1"><em>RFC1305</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC1305.1">3.3</a>, <a class="iref" href="#RFC1305"><b>7.2</b></a></li>
     3306                  <li class="indline1"><em>RFC1900</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC1900.1">5.4</a>, <a class="iref" href="#RFC1900"><b>7.2</b></a></li>
     3307                  <li class="indline1"><em>RFC1945</em>&nbsp;&nbsp;<a class="iref" href="#RFC1945"><b>7.2</b></a>, <a class="iref" href="#rfc.xref.RFC1945.1">B</a></li>
     3308                  <li class="indline1"><em>RFC2045</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2045.1">1</a>, <a class="iref" href="#rfc.xref.RFC2045.2">2.10.2</a>, <a class="iref" href="#rfc.xref.RFC2045.3">6</a>, <a class="iref" href="#RFC2045"><b>7.2</b></a><ul class="ind">
     3309                        <li class="indline1"><em>Section 6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2045.2">2.10.2</a></li>
    32803310                     </ul>
    32813311                  </li>
    3282                   <li class="indline1"><em>RFC2047</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2047.1">3.2</a>, <a class="iref" href="#RFC2047"><b>12.2</b></a></li>
    3283                   <li class="indline1"><em>RFC2068</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2068.1">2.5</a>, <a class="iref" href="#rfc.xref.RFC2068.2">7.1.3</a>, <a class="iref" href="#rfc.xref.RFC2068.3">7.2.3</a>, <a class="iref" href="#rfc.xref.RFC2068.4">11</a>, <a class="iref" href="#RFC2068"><b>12.2</b></a>, <a class="iref" href="#rfc.xref.RFC2068.5">B</a>, <a class="iref" href="#rfc.xref.RFC2068.6">B.2</a><ul class="ind">
    3284                         <li class="indline1"><em>Section 19.7.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2068.2">7.1.3</a>, <a class="iref" href="#rfc.xref.RFC2068.5">B</a>, <a class="iref" href="#rfc.xref.RFC2068.6">B.2</a></li>
     3312                  <li class="indline1"><em>RFC2047</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2047.1">2.7.2</a>, <a class="iref" href="#RFC2047"><b>7.2</b></a></li>
     3313                  <li class="indline1"><em>RFC2068</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2068.1">2.5</a>, <a class="iref" href="#rfc.xref.RFC2068.2">2.11.1.3</a>, <a class="iref" href="#rfc.xref.RFC2068.3">2.11.2.3</a>, <a class="iref" href="#rfc.xref.RFC2068.4">6</a>, <a class="iref" href="#RFC2068"><b>7.2</b></a>, <a class="iref" href="#rfc.xref.RFC2068.5">B</a>, <a class="iref" href="#rfc.xref.RFC2068.6">B.2</a><ul class="ind">
     3314                        <li class="indline1"><em>Section 19.7.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2068.2">2.11.1.3</a>, <a class="iref" href="#rfc.xref.RFC2068.5">B</a>, <a class="iref" href="#rfc.xref.RFC2068.6">B.2</a></li>
    32853315                     </ul>
    32863316                  </li>
    3287                   <li class="indline1"><em>RFC2109</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2109.1">3.2</a>, <a class="iref" href="#RFC2109"><b>12.2</b></a></li>
    3288                   <li class="indline1"><em>RFC2119</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2119.1">1.1</a>, <a class="iref" href="#RFC2119"><b>12.1</b></a>, <a class="iref" href="#rfc.xref.RFC2119.2">B.3</a></li>
    3289                   <li class="indline1"><em>RFC2145</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2145.1">2.5</a>, <a class="iref" href="#rfc.xref.RFC2145.2">2.5</a>, <a class="iref" href="#RFC2145"><b>12.2</b></a>, <a class="iref" href="#rfc.xref.RFC2145.3">B.3</a></li>
    3290                   <li class="indline1"><em>RFC2616</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2616.1">1</a>, <a class="iref" href="#rfc.xref.RFC2616.2">11</a>, <a class="iref" href="#RFC2616"><b>12.2</b></a>, <a class="iref" href="#rfc.xref.RFC2616.3">E.1</a></li>
    3291                   <li class="indline1"><em>RFC2818</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2818.1">2.6.2</a>, <a class="iref" href="#RFC2818"><b>12.2</b></a></li>
    3292                   <li class="indline1"><em>RFC2965</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2965.1">3.2</a>, <a class="iref" href="#RFC2965"><b>12.2</b></a></li>
    3293                   <li class="indline1"><em>RFC3864</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3864.1">9.1</a>, <a class="iref" href="#RFC3864"><b>12.2</b></a></li>
    3294                   <li class="indline1"><em>RFC3986</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.1">1</a>, <a class="iref" href="#rfc.xref.RFC3986.2">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.3">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.4">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.5">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.6">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.7">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.8">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.9">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.10">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.11">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.12">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.13">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.14">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.15">2.6.1</a>, <a class="iref" href="#rfc.xref.RFC3986.16">2.6.3</a>, <a class="iref" href="#rfc.xref.RFC3986.17">2.6.3</a>, <a class="iref" href="#rfc.xref.RFC3986.18">4.1.2</a>, <a class="iref" href="#RFC3986"><b>12.1</b></a><ul class="ind">
    3295                         <li class="indline1"><em>Section 2.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.17">2.6.3</a>, <a class="iref" href="#rfc.xref.RFC3986.18">4.1.2</a></li>
     3317                  <li class="indline1"><em>RFC2109</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2109.1">2.7.2</a>, <a class="iref" href="#RFC2109"><b>7.2</b></a></li>
     3318                  <li class="indline1"><em>RFC2119</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2119.1">1.1</a>, <a class="iref" href="#RFC2119"><b>7.1</b></a>, <a class="iref" href="#rfc.xref.RFC2119.2">B.3</a></li>
     3319                  <li class="indline1"><em>RFC2145</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2145.1">2.5</a>, <a class="iref" href="#rfc.xref.RFC2145.2">2.5</a>, <a class="iref" href="#RFC2145"><b>7.2</b></a>, <a class="iref" href="#rfc.xref.RFC2145.3">B.3</a></li>
     3320                  <li class="indline1"><em>RFC2616</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2616.1">1</a>, <a class="iref" href="#rfc.xref.RFC2616.2">6</a>, <a class="iref" href="#RFC2616"><b>7.2</b></a>, <a class="iref" href="#rfc.xref.RFC2616.3">E.1</a></li>
     3321                  <li class="indline1"><em>RFC2818</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2818.1">2.6.2</a>, <a class="iref" href="#RFC2818"><b>7.2</b></a></li>
     3322                  <li class="indline1"><em>RFC2965</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2965.1">2.7.2</a>, <a class="iref" href="#RFC2965"><b>7.2</b></a></li>
     3323                  <li class="indline1"><em>RFC3864</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3864.1">4.1</a>, <a class="iref" href="#RFC3864"><b>7.2</b></a></li>
     3324                  <li class="indline1"><em>RFC3986</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.1">1</a>, <a class="iref" href="#rfc.xref.RFC3986.2">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.3">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.4">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.5">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.6">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.7">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.8">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.9">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.10">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.11">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.12">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.13">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.14">2.6</a>, <a class="iref" href="#rfc.xref.RFC3986.15">2.6.1</a>, <a class="iref" href="#rfc.xref.RFC3986.16">2.6.3</a>, <a class="iref" href="#rfc.xref.RFC3986.17">2.6.3</a>, <a class="iref" href="#rfc.xref.RFC3986.18">2.8.1.2</a>, <a class="iref" href="#RFC3986"><b>7.1</b></a><ul class="ind">
     3325                        <li class="indline1"><em>Section 2.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.17">2.6.3</a>, <a class="iref" href="#rfc.xref.RFC3986.18">2.8.1.2</a></li>
    32963326                        <li class="indline1"><em>Section 3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.5">2.6</a></li>
    32973327                        <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.9">2.6</a></li>
     
    33063336                     </ul>
    33073337                  </li>
    3308                   <li class="indline1"><em>RFC4288</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC4288.1">9.3</a>, <a class="iref" href="#RFC4288"><b>12.2</b></a></li>
    3309                   <li class="indline1"><em>RFC4395</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC4395.1">9.2</a>, <a class="iref" href="#RFC4395"><b>12.2</b></a></li>
    3310                   <li class="indline1"><em>RFC5234</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5234.1">1.2</a>, <a class="iref" href="#rfc.xref.RFC5234.2">1.2</a>, <a class="iref" href="#rfc.xref.RFC5234.3">1.2.1</a>, <a class="iref" href="#rfc.xref.RFC5234.4">11</a>, <a class="iref" href="#RFC5234"><b>12.1</b></a><ul class="ind">
     3338                  <li class="indline1"><em>RFC4288</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC4288.1">4.3</a>, <a class="iref" href="#RFC4288"><b>7.2</b></a></li>
     3339                  <li class="indline1"><em>RFC4395</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC4395.1">4.2</a>, <a class="iref" href="#RFC4395"><b>7.2</b></a></li>
     3340                  <li class="indline1"><em>RFC5234</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5234.1">1.2</a>, <a class="iref" href="#rfc.xref.RFC5234.2">1.2</a>, <a class="iref" href="#rfc.xref.RFC5234.3">1.2.1</a>, <a class="iref" href="#rfc.xref.RFC5234.4">6</a>, <a class="iref" href="#RFC5234"><b>7.1</b></a><ul class="ind">
    33113341                        <li class="indline1"><em>Appendix B.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5234.2">1.2</a></li>
    33123342                     </ul>
    33133343                  </li>
    3314                   <li class="indline1"><em>RFC5322</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.1">1</a>, <a class="iref" href="#rfc.xref.RFC5322.2">3</a>, <a class="iref" href="#rfc.xref.RFC5322.3">6.1</a>, <a class="iref" href="#rfc.xref.RFC5322.4">8.3</a>, <a class="iref" href="#rfc.xref.RFC5322.5">8.9</a>, <a class="iref" href="#RFC5322"><b>12.2</b></a><ul class="ind">
    3315                         <li class="indline1"><em>Section 3.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.3">6.1</a></li>
    3316                         <li class="indline1"><em>Section 3.6.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.4">8.3</a></li>
    3317                         <li class="indline1"><em>Section 3.6.7</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.5">8.9</a></li>
     3344                  <li class="indline1"><em>RFC5322</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.1">1</a>, <a class="iref" href="#rfc.xref.RFC5322.2">2.7</a>, <a class="iref" href="#rfc.xref.RFC5322.3">2.10.1</a>, <a class="iref" href="#rfc.xref.RFC5322.4">3.3</a>, <a class="iref" href="#rfc.xref.RFC5322.5">3.9</a>, <a class="iref" href="#RFC5322"><b>7.2</b></a><ul class="ind">
     3345                        <li class="indline1"><em>Section 3.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.3">2.10.1</a></li>
     3346                        <li class="indline1"><em>Section 3.6.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.4">3.3</a></li>
     3347                        <li class="indline1"><em>Section 3.6.7</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.5">3.9</a></li>
    33183348                     </ul>
    33193349                  </li>
     
    33223352            <li class="indline0"><a id="rfc.index.S" href="#rfc.index.S"><b>S</b></a><ul class="ind">
    33233353                  <li class="indline1">server&nbsp;&nbsp;<a class="iref" href="#rfc.iref.s.1">2.1</a></li>
    3324                   <li class="indline1"><em>Spe</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Spe.1">7.1.1</a>, <a class="iref" href="#Spe"><b>12.2</b></a></li>
     3354                  <li class="indline1"><em>Spe</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Spe.1">2.11.1.1</a>, <a class="iref" href="#Spe"><b>7.2</b></a></li>
    33253355               </ul>
    33263356            </li>
    33273357            <li class="indline0"><a id="rfc.index.T" href="#rfc.index.T"><b>T</b></a><ul class="ind">
    3328                   <li class="indline1">TE header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.te.1">6.2</a>, <a class="iref" href="#rfc.xref.header.te.2">6.2.1</a>, <a class="iref" href="#rfc.xref.header.te.3">6.4</a>, <a class="iref" href="#rfc.iref.t.2"><b>8.5</b></a>, <a class="iref" href="#rfc.xref.header.te.4">9.1</a>, <a class="iref" href="#rfc.xref.header.te.5">B.3</a></li>
    3329                   <li class="indline1"><em>Tou1998</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Tou1998.1">7.1.1</a>, <a class="iref" href="#Tou1998"><b>12.2</b></a></li>
    3330                   <li class="indline1">Trailer header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.trailer.1">3.5</a>, <a class="iref" href="#rfc.xref.header.trailer.2">6.2.1</a>, <a class="iref" href="#rfc.iref.t.3"><b>8.6</b></a>, <a class="iref" href="#rfc.xref.header.trailer.3">9.1</a></li>
    3331                   <li class="indline1">Transfer-Encoding header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.transfer-encoding.1">3.3</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.2">3.4</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.3">3.5</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.4">6.2</a>, <a class="iref" href="#rfc.iref.t.4"><b>8.7</b></a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.5">9.1</a></li>
     3358                  <li class="indline1">TE header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.te.1">2.10.2</a>, <a class="iref" href="#rfc.xref.header.te.2">2.10.2.1</a>, <a class="iref" href="#rfc.xref.header.te.3">2.10.4</a>, <a class="iref" href="#rfc.iref.t.2"><b>3.5</b></a>, <a class="iref" href="#rfc.xref.header.te.4">4.1</a>, <a class="iref" href="#rfc.xref.header.te.5">B.3</a></li>
     3359                  <li class="indline1"><em>Tou1998</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Tou1998.1">2.11.1.1</a>, <a class="iref" href="#Tou1998"><b>7.2</b></a></li>
     3360                  <li class="indline1">Trailer header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.trailer.1">2.7.5</a>, <a class="iref" href="#rfc.xref.header.trailer.2">2.10.2.1</a>, <a class="iref" href="#rfc.iref.t.3"><b>3.6</b></a>, <a class="iref" href="#rfc.xref.header.trailer.3">4.1</a></li>
     3361                  <li class="indline1">Transfer-Encoding header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.transfer-encoding.1">2.7.3</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.2">2.7.4</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.3">2.7.5</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.4">2.10.2</a>, <a class="iref" href="#rfc.iref.t.4"><b>3.7</b></a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.5">4.1</a></li>
    33323362                  <li class="indline1">tunnel&nbsp;&nbsp;<a class="iref" href="#rfc.iref.t.1">2.2</a></li>
    33333363               </ul>
    33343364            </li>
    33353365            <li class="indline0"><a id="rfc.index.U" href="#rfc.index.U"><b>U</b></a><ul class="ind">
    3336                   <li class="indline1">Upgrade header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.upgrade.1">3.5</a>, <a class="iref" href="#rfc.iref.u.5"><b>8.8</b></a>, <a class="iref" href="#rfc.xref.header.upgrade.2">9.1</a></li>
     3366                  <li class="indline1">Upgrade header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.upgrade.1">2.7.5</a>, <a class="iref" href="#rfc.iref.u.5"><b>3.8</b></a>, <a class="iref" href="#rfc.xref.header.upgrade.2">4.1</a></li>
    33373367                  <li class="indline1">upstream&nbsp;&nbsp;<a class="iref" href="#rfc.iref.u.2">2.2</a></li>
    33383368                  <li class="indline1">URI scheme&nbsp;&nbsp;
     
    33423372                     </ul>
    33433373                  </li>
    3344                   <li class="indline1"><em>USASCII</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.USASCII.1">1.2</a>, <a class="iref" href="#rfc.xref.USASCII.2">3.2</a>, <a class="iref" href="#USASCII"><b>12.1</b></a></li>
     3374                  <li class="indline1"><em>USASCII</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.USASCII.1">1.2</a>, <a class="iref" href="#rfc.xref.USASCII.2">2.7.2</a>, <a class="iref" href="#USASCII"><b>7.1</b></a></li>
    33453375                  <li class="indline1">user agent&nbsp;&nbsp;<a class="iref" href="#rfc.iref.u.1">2.1</a></li>
    33463376               </ul>
     
    33483378            <li class="indline0"><a id="rfc.index.V" href="#rfc.index.V"><b>V</b></a><ul class="ind">
    33493379                  <li class="indline1">variant&nbsp;&nbsp;<a class="iref" href="#rfc.iref.v.2">C</a></li>
    3350                   <li class="indline1">Via header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.via.1">3.5</a>, <a class="iref" href="#rfc.iref.v.1"><b>8.9</b></a>, <a class="iref" href="#rfc.xref.header.via.2">9.1</a></li>
     3380                  <li class="indline1">Via header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.via.1">2.7.5</a>, <a class="iref" href="#rfc.iref.v.1"><b>3.9</b></a>, <a class="iref" href="#rfc.xref.header.via.2">4.1</a></li>
    33513381               </ul>
    33523382            </li>
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