Changeset 626 for draft-ietf-httpbis


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26/07/09 12:17:52 (12 years ago)
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  • draft-ietf-httpbis/latest/p1-messaging.html

    r622 r626  
    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 Protocol Parameters" href="#rfc.section.3">
    363       <link rel="Chapter" title="4 HTTP Message" href="#rfc.section.4">
    364       <link rel="Chapter" title="5 Request" href="#rfc.section.5">
    365       <link rel="Chapter" title="6 Response" href="#rfc.section.6">
     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">
    366366      <link rel="Chapter" title="7 Connections" href="#rfc.section.7">
    367367      <link rel="Chapter" title="8 Header Field Definitions" href="#rfc.section.8">
    … …  
    529529         </li>
    530530         <li class="tocline0">2.&nbsp;&nbsp;&nbsp;<a href="#architecture">HTTP architecture</a><ul class="toc">
    531                <li class="tocline1">2.1&nbsp;&nbsp;&nbsp;<a href="#uri">Uniform Resource Identifiers</a><ul class="toc">
    532                      <li class="tocline1">2.1.1&nbsp;&nbsp;&nbsp;<a href="#http.uri">http URI scheme</a></li>
    533                      <li class="tocline1">2.1.2&nbsp;&nbsp;&nbsp;<a href="#https.uri">https URI scheme</a></li>
    534                      <li class="tocline1">2.1.3&nbsp;&nbsp;&nbsp;<a href="#uri.comparison">http and https URI Normalization and Comparison</a></li>
    535                      <li class="tocline1">2.1.4&nbsp;&nbsp;&nbsp;<a href="#scheme.aliases">Scheme aliases considered harmful</a></li>
     531               <li class="tocline1">2.1&nbsp;&nbsp;&nbsp;<a href="#intro.overall.operation">Overall Operation</a></li>
     532               <li class="tocline1">2.2&nbsp;&nbsp;&nbsp;<a href="#http.version">HTTP Version</a></li>
     533               <li class="tocline1">2.3&nbsp;&nbsp;&nbsp;<a href="#uri">Uniform Resource Identifiers</a><ul class="toc">
     534                     <li class="tocline1">2.3.1&nbsp;&nbsp;&nbsp;<a href="#http.uri">http URI scheme</a></li>
     535                     <li class="tocline1">2.3.2&nbsp;&nbsp;&nbsp;<a href="#https.uri">https URI scheme</a></li>
     536                     <li class="tocline1">2.3.3&nbsp;&nbsp;&nbsp;<a href="#uri.comparison">http and https URI Normalization and Comparison</a></li>
     537                     <li class="tocline1">2.3.4&nbsp;&nbsp;&nbsp;<a href="#scheme.aliases">Scheme aliases considered harmful</a></li>
    536538                  </ul>
    537539               </li>
    538                <li class="tocline1">2.2&nbsp;&nbsp;&nbsp;<a href="#intro.overall.operation">Overall Operation</a></li>
    539                <li class="tocline1">2.3&nbsp;&nbsp;&nbsp;<a href="#http.proxy">Use of HTTP for proxy communication</a></li>
    540                <li class="tocline1">2.4&nbsp;&nbsp;&nbsp;<a href="#http.intercept">Interception of HTTP for access control</a></li>
    541                <li class="tocline1">2.5&nbsp;&nbsp;&nbsp;<a href="#http.others">Use of HTTP by other protocols</a></li>
    542                <li class="tocline1">2.6&nbsp;&nbsp;&nbsp;<a href="#http.media">Use of HTTP by media type specification</a></li>
     540               <li class="tocline1">2.4&nbsp;&nbsp;&nbsp;<a href="#http.proxy">Use of HTTP for proxy communication</a></li>
     541               <li class="tocline1">2.5&nbsp;&nbsp;&nbsp;<a href="#http.intercept">Interception of HTTP for access control</a></li>
     542               <li class="tocline1">2.6&nbsp;&nbsp;&nbsp;<a href="#http.others">Use of HTTP by other protocols</a></li>
     543               <li class="tocline1">2.7&nbsp;&nbsp;&nbsp;<a href="#http.media">Use of HTTP by media type specification</a></li>
    543544            </ul>
    544545         </li>
    545          <li class="tocline0">3.&nbsp;&nbsp;&nbsp;<a href="#protocol.parameters">Protocol Parameters</a><ul class="toc">
    546                <li class="tocline1">3.1&nbsp;&nbsp;&nbsp;<a href="#http.version">HTTP Version</a></li>
    547                <li class="tocline1">3.2&nbsp;&nbsp;&nbsp;<a href="#date.time.formats.full.date">Date/Time Formats: Full Date</a></li>
    548                <li class="tocline1">3.3&nbsp;&nbsp;&nbsp;<a href="#transfer.codings">Transfer Codings</a><ul class="toc">
    549                      <li class="tocline1">3.3.1&nbsp;&nbsp;&nbsp;<a href="#chunked.transfer.encoding">Chunked Transfer Coding</a></li>
     546         <li class="tocline0">3.&nbsp;&nbsp;&nbsp;<a href="#http.message">HTTP Message</a><ul class="toc">
     547               <li class="tocline1">3.1&nbsp;&nbsp;&nbsp;<a href="#message.types">Message Types</a></li>
     548               <li class="tocline1">3.2&nbsp;&nbsp;&nbsp;<a href="#message.headers">Message Headers</a></li>
     549               <li class="tocline1">3.3&nbsp;&nbsp;&nbsp;<a href="#message.body">Message Body</a></li>
     550               <li class="tocline1">3.4&nbsp;&nbsp;&nbsp;<a href="#message.length">Message Length</a></li>
     551               <li class="tocline1">3.5&nbsp;&nbsp;&nbsp;<a href="#general.header.fields">General Header Fields</a></li>
     552            </ul>
     553         </li>
     554         <li class="tocline0">4.&nbsp;&nbsp;&nbsp;<a href="#request">Request</a><ul class="toc">
     555               <li class="tocline1">4.1&nbsp;&nbsp;&nbsp;<a href="#request-line">Request-Line</a><ul class="toc">
     556                     <li class="tocline1">4.1.1&nbsp;&nbsp;&nbsp;<a href="#method">Method</a></li>
     557                     <li class="tocline1">4.1.2&nbsp;&nbsp;&nbsp;<a href="#request-target">request-target</a></li>
    550558                  </ul>
    551559               </li>
    552                <li class="tocline1">3.4&nbsp;&nbsp;&nbsp;<a href="#product.tokens">Product Tokens</a></li>
    553                <li class="tocline1">3.5&nbsp;&nbsp;&nbsp;<a href="#quality.values">Quality Values</a></li>
     560               <li class="tocline1">4.2&nbsp;&nbsp;&nbsp;<a href="#the.resource.identified.by.a.request">The Resource Identified by a Request</a></li>
    554561            </ul>
    555562         </li>
    556          <li class="tocline0">4.&nbsp;&nbsp;&nbsp;<a href="#http.message">HTTP Message</a><ul class="toc">
    557                <li class="tocline1">4.1&nbsp;&nbsp;&nbsp;<a href="#message.types">Message Types</a></li>
    558                <li class="tocline1">4.2&nbsp;&nbsp;&nbsp;<a href="#message.headers">Message Headers</a></li>
    559                <li class="tocline1">4.3&nbsp;&nbsp;&nbsp;<a href="#message.body">Message Body</a></li>
    560                <li class="tocline1">4.4&nbsp;&nbsp;&nbsp;<a href="#message.length">Message Length</a></li>
    561                <li class="tocline1">4.5&nbsp;&nbsp;&nbsp;<a href="#general.header.fields">General Header Fields</a></li>
    562             </ul>
    563          </li>
    564          <li class="tocline0">5.&nbsp;&nbsp;&nbsp;<a href="#request">Request</a><ul class="toc">
    565                <li class="tocline1">5.1&nbsp;&nbsp;&nbsp;<a href="#request-line">Request-Line</a><ul class="toc">
    566                      <li class="tocline1">5.1.1&nbsp;&nbsp;&nbsp;<a href="#method">Method</a></li>
    567                      <li class="tocline1">5.1.2&nbsp;&nbsp;&nbsp;<a href="#request-target">request-target</a></li>
     563         <li class="tocline0">5.&nbsp;&nbsp;&nbsp;<a href="#response">Response</a><ul class="toc">
     564               <li class="tocline1">5.1&nbsp;&nbsp;&nbsp;<a href="#status-line">Status-Line</a><ul class="toc">
     565                     <li class="tocline1">5.1.1&nbsp;&nbsp;&nbsp;<a href="#status.code.and.reason.phrase">Status Code and Reason Phrase</a></li>
    568566                  </ul>
    569567               </li>
    570                <li class="tocline1">5.2&nbsp;&nbsp;&nbsp;<a href="#the.resource.identified.by.a.request">The Resource Identified by a Request</a></li>
    571568            </ul>
    572569         </li>
    573          <li class="tocline0">6.&nbsp;&nbsp;&nbsp;<a href="#response">Response</a><ul class="toc">
    574                <li class="tocline1">6.1&nbsp;&nbsp;&nbsp;<a href="#status-line">Status-Line</a><ul class="toc">
    575                      <li class="tocline1">6.1.1&nbsp;&nbsp;&nbsp;<a href="#status.code.and.reason.phrase">Status Code and Reason Phrase</a></li>
     570         <li class="tocline0">6.&nbsp;&nbsp;&nbsp;<a href="#protocol.parameters">Protocol Parameters</a><ul class="toc">
     571               <li class="tocline1">6.1&nbsp;&nbsp;&nbsp;<a href="#date.time.formats.full.date">Date/Time Formats: Full Date</a></li>
     572               <li class="tocline1">6.2&nbsp;&nbsp;&nbsp;<a href="#transfer.codings">Transfer Codings</a><ul class="toc">
     573                     <li class="tocline1">6.2.1&nbsp;&nbsp;&nbsp;<a href="#chunked.transfer.encoding">Chunked Transfer Coding</a></li>
    576574                  </ul>
    577575               </li>
     576               <li class="tocline1">6.3&nbsp;&nbsp;&nbsp;<a href="#product.tokens">Product Tokens</a></li>
     577               <li class="tocline1">6.4&nbsp;&nbsp;&nbsp;<a href="#quality.values">Quality Values</a></li>
    578578            </ul>
    579579         </li>
    … …  
    766766                 ; "bad" whitespace
    767767  <a href="#rule.whitespace" class="smpl">obs-fold</a>       = <a href="#core.rules" class="smpl">CRLF</a>
    768                  ; see <a href="#message.headers" title="Message Headers">Section&nbsp;4.2</a>
     768                 ; see <a href="#message.headers" title="Message Headers">Section&nbsp;3.2</a>
    769769</pre><div id="rule.token.separators">
    770          <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;3.3</a>).
     770         <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>).
    771771         </p>
    772772      </div>
    … …  
    804804         hypertext system. Much of that architecture is reflected in the terminology and syntax productions used to define HTTP.
    805805      </p>
     806      <h2 id="rfc.section.2.1"><a href="#rfc.section.2.1">2.1</a>&nbsp;<a id="intro.overall.operation" href="#intro.overall.operation">Overall Operation</a></h2>
     807      <p id="rfc.section.2.1.p.1">HTTP is a request/response protocol. A client sends a request to the server in the form of a request method, URI, and protocol
     808         version, followed by a MIME-like message containing request modifiers, client information, and possible body content over
     809         a connection with a server. The server responds with a status line, including the message's protocol version and a success
     810         or error code, followed by a MIME-like message containing server information, entity metadata, and possible entity-body content.
     811      </p>
     812      <p id="rfc.section.2.1.p.2">Most HTTP communication is initiated by a user agent and consists of a request to be applied to a resource via the HTTP interface
     813         provided by some origin server. In the simplest case, this may be accomplished via a single connection (v) between the user
     814         agent (UA) and the origin server (O).
     815      </p>
     816      <div id="rfc.figure.u.12"></div><pre class="drawing">       request chain ------------------------&gt;
     817    UA -------------------v------------------- O
     818       &lt;----------------------- response chain
     819</pre><p id="rfc.section.2.1.p.4">A more complicated situation occurs when one or more intermediaries are present in the request/response chain. There are three
     820         common forms of intermediary: proxy, gateway, and tunnel. A proxy is a forwarding agent, receiving requests for a URI in its
     821         absolute form, rewriting all or part of the message, and forwarding the reformatted request toward the server identified by
     822         the URI. A gateway is a receiving agent, acting as a layer above some other server(s) and, if necessary, translating the requests
     823         to the underlying server's protocol. A tunnel acts as a relay point between two connections without changing the messages;
     824         tunnels are used when the communication needs to pass through an intermediary (such as a firewall) even when the intermediary
     825         cannot understand the contents of the messages.
     826      </p>
     827      <div id="rfc.figure.u.13"></div><pre class="drawing">       request chain --------------------------------------&gt;
     828    UA -----v----- A -----v----- B -----v----- C -----v----- O
     829       &lt;------------------------------------- response chain
     830</pre><p id="rfc.section.2.1.p.6">The figure above shows three intermediaries (A, B, and C) between the user agent and origin server. A request or response
     831         message that travels the whole chain will pass through four separate connections. This distinction is important because some
     832         HTTP communication options may apply only to the connection with the nearest, non-tunnel neighbor, only to the end-points
     833         of the chain, or to all connections along the chain. Although the diagram is linear, each participant may be engaged in multiple,
     834         simultaneous communications. For example, B may be receiving requests from many clients other than A, and/or forwarding requests
     835         to servers other than C, at the same time that it is handling A's request.
     836      </p>
     837      <p id="rfc.section.2.1.p.7">Any party to the communication which is not acting as a tunnel may employ an internal cache for handling requests. The effect
     838         of a cache is that the request/response chain is shortened if one of the participants along the chain has a cached response
     839         applicable to that request. The following illustrates the resulting chain if B has a cached copy of an earlier response from
     840         O (via C) for a request which has not been cached by UA or A.
     841      </p>
     842      <div id="rfc.figure.u.14"></div><pre class="drawing">          request chain ----------&gt;
     843       UA -----v----- A -----v----- B - - - - - - C - - - - - - O
     844          &lt;--------- response chain
     845</pre><p id="rfc.section.2.1.p.9">Not all responses are usefully cacheable, and some requests may contain modifiers which place special requirements on cache
     846         behavior. HTTP requirements for cache behavior and cacheable responses are defined in <a href="p6-cache.html#caching" title="Introduction">Section 1</a> of <a href="#Part6" id="rfc.xref.Part6.4"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>.
     847      </p>
     848      <p id="rfc.section.2.1.p.10">In fact, there are a wide variety of architectures and configurations of caches and proxies currently being experimented with
     849         or deployed across the World Wide Web. These systems include national hierarchies of proxy caches to save transoceanic bandwidth,
     850         systems that broadcast or multicast cache entries, organizations that distribute subsets of cached data via CD-ROM, and so
     851         on. HTTP systems are used in corporate intranets over high-bandwidth links, and for access via PDAs with low-power radio links
     852         and intermittent connectivity. The goal of HTTP/1.1 is to support the wide diversity of configurations already deployed while
     853         introducing protocol constructs that meet the needs of those who build web applications that require high reliability and,
     854         failing that, at least reliable indications of failure.
     855      </p>
     856      <p id="rfc.section.2.1.p.11">HTTP communication usually takes place over TCP/IP connections. The default port is TCP 80 (&lt;<a href="http://www.iana.org/assignments/port-numbers">http://www.iana.org/assignments/port-numbers</a>&gt;), but other ports can be used. This does not preclude HTTP from being implemented on top of any other protocol on the Internet,
     857         or on other networks. HTTP only presumes a reliable transport; any protocol that provides such guarantees can be used; the
     858         mapping of the HTTP/1.1 request and response structures onto the transport data units of the protocol in question is outside
     859         the scope of this specification.
     860      </p>
     861      <p id="rfc.section.2.1.p.12">In HTTP/1.0, most implementations used a new connection for each request/response exchange. In HTTP/1.1, a connection may
     862         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>).
     863      </p>
     864      <h2 id="rfc.section.2.2"><a href="#rfc.section.2.2">2.2</a>&nbsp;<a id="http.version" href="#http.version">HTTP Version</a></h2>
     865      <p id="rfc.section.2.2.p.1">HTTP uses a "&lt;major&gt;.&lt;minor&gt;" numbering scheme to indicate versions of the protocol. The protocol versioning policy is intended
     866         to allow the sender to indicate the format of a message and its capacity for understanding further HTTP communication, rather
     867         than the features obtained via that communication. No change is made to the version number for the addition of message components
     868         which do not affect communication behavior or which only add to extensible field values. The &lt;minor&gt; number is incremented
     869         when the changes made to the protocol add features which do not change the general message parsing algorithm, but which may
     870         add to the message semantics and imply additional capabilities of the sender. The &lt;major&gt; number is incremented when the format
     871         of a message within the protocol is changed. See <a href="#RFC2145" id="rfc.xref.RFC2145.1"><cite title="Use and Interpretation of HTTP Version Numbers">[RFC2145]</cite></a> for a fuller explanation.
     872      </p>
     873      <p id="rfc.section.2.2.p.2">The version of an HTTP message is indicated by an HTTP-Version field in the first line of the message. HTTP-Version is case-sensitive.</p>
     874      <div id="rfc.figure.u.15"></div><pre class="inline"><span id="rfc.iref.g.23"></span><span id="rfc.iref.g.24"></span>  <a href="#http.version" class="smpl">HTTP-Version</a>   = <a href="#http.version" class="smpl">HTTP-Prot-Name</a> "/" 1*<a href="#core.rules" class="smpl">DIGIT</a> "." 1*<a href="#core.rules" class="smpl">DIGIT</a>
     875  <a href="#http.version" class="smpl">HTTP-Prot-Name</a> = %x48.54.54.50 ; "HTTP", case-sensitive
     876</pre><p id="rfc.section.2.2.p.4">Note that the major and minor numbers <em class="bcp14">MUST</em> be treated as separate integers and that each <em class="bcp14">MAY</em> be incremented higher than a single digit. Thus, HTTP/2.4 is a lower version than HTTP/2.13, which in turn is lower than HTTP/12.3.
     877         Leading zeros <em class="bcp14">MUST</em> be ignored by recipients and <em class="bcp14">MUST NOT</em> be sent.
     878      </p>
     879      <p id="rfc.section.2.2.p.5">An application that sends a request or response message that includes HTTP-Version of "HTTP/1.1" <em class="bcp14">MUST</em> be at least conditionally compliant with this specification. Applications that are at least conditionally compliant with this
     880         specification <em class="bcp14">SHOULD</em> use an HTTP-Version of "HTTP/1.1" in their messages, and <em class="bcp14">MUST</em> do so for any message that is not compatible with HTTP/1.0. For more details on when to send specific HTTP-Version values,
     881         see <a href="#RFC2145" id="rfc.xref.RFC2145.2"><cite title="Use and Interpretation of HTTP Version Numbers">[RFC2145]</cite></a>.
     882      </p>
     883      <p id="rfc.section.2.2.p.6">The HTTP version of an application is the highest HTTP version for which the application is at least conditionally compliant.</p>
     884      <p id="rfc.section.2.2.p.7">Proxy and gateway applications need to be careful when forwarding messages in protocol versions different from that of the
     885         application. Since the protocol version indicates the protocol capability of the sender, a proxy/gateway <em class="bcp14">MUST NOT</em> send a message with a version indicator which is greater than its actual version. If a higher version request is received,
     886         the proxy/gateway <em class="bcp14">MUST</em> either downgrade the request version, or respond with an error, or switch to tunnel behavior.
     887      </p>
     888      <p id="rfc.section.2.2.p.8">Due to interoperability problems with HTTP/1.0 proxies discovered since the publication of <a href="#RFC2068" id="rfc.xref.RFC2068.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a>, caching proxies <em class="bcp14">MUST</em>, gateways <em class="bcp14">MAY</em>, and tunnels <em class="bcp14">MUST NOT</em> upgrade the request to the highest version they support. The proxy/gateway's response to that request <em class="bcp14">MUST</em> be in the same major version as the request.
     889      </p>
     890      <div class="note">
     891         <p> <b>Note:</b> Converting between versions of HTTP may involve modification of header fields required or forbidden by the versions involved.
     892         </p>
     893      </div>
    806894      <div id="rfc.iref.r.1"></div>
    807       <h2 id="rfc.section.2.1"><a href="#rfc.section.2.1">2.1</a>&nbsp;<a id="uri" href="#uri">Uniform Resource Identifiers</a></h2>
    808       <p id="rfc.section.2.1.p.1">Uniform Resource Identifiers (URIs) <a href="#RFC3986" id="rfc.xref.RFC3986.2"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a> are used throughout HTTP as the means for identifying resources. URI references are used to target requests, indicate redirects,
     895      <h2 id="rfc.section.2.3"><a href="#rfc.section.2.3">2.3</a>&nbsp;<a id="uri" href="#uri">Uniform Resource Identifiers</a></h2>
     896      <p id="rfc.section.2.3.p.1">Uniform Resource Identifiers (URIs) <a href="#RFC3986" id="rfc.xref.RFC3986.2"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a> are used throughout HTTP as the means for identifying resources. URI references are used to target requests, indicate redirects,
    809897         and define relationships. HTTP does not limit what a resource may be; it merely defines an interface that can be used to interact
    810898         with a resource via HTTP. More information on the scope of URIs and resources can be found in <a href="#RFC3986" id="rfc.xref.RFC3986.3"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>.
    811899      </p>
    812       <p id="rfc.section.2.1.p.2">This specification adopts the definitions of "URI-reference", "absolute-URI", "relative-part", "fragment", "port", "host",
     900      <p id="rfc.section.2.3.p.2">This specification adopts the definitions of "URI-reference", "absolute-URI", "relative-part", "fragment", "port", "host",
    813901         "path-abempty", "path-absolute", "query", and "authority" from <a href="#RFC3986" id="rfc.xref.RFC3986.4"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>. In addition, we define a partial-URI rule for protocol elements that allow a relative URI without a fragment.
    814902      </p>
    815       <div id="rfc.figure.u.12"></div><pre class="inline"><span id="rfc.iref.g.23"></span><span id="rfc.iref.g.24"></span><span id="rfc.iref.g.25"></span><span id="rfc.iref.g.26"></span><span id="rfc.iref.g.27"></span><span id="rfc.iref.g.28"></span><span id="rfc.iref.g.29"></span>  <a href="#uri" class="smpl">URI</a>           = &lt;URI, defined in <a href="#RFC3986" id="rfc.xref.RFC3986.5"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-3">Section 3</a>&gt;
     903      <div id="rfc.figure.u.16"></div><pre class="inline"><span id="rfc.iref.g.25"></span><span id="rfc.iref.g.26"></span><span id="rfc.iref.g.27"></span><span id="rfc.iref.g.28"></span><span id="rfc.iref.g.29"></span><span id="rfc.iref.g.30"></span><span id="rfc.iref.g.31"></span>  <a href="#uri" class="smpl">URI</a>           = &lt;URI, defined in <a href="#RFC3986" id="rfc.xref.RFC3986.5"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-3">Section 3</a>&gt;
    816904  <a href="#uri" class="smpl">URI-reference</a> = &lt;URI-reference, defined in <a href="#RFC3986" id="rfc.xref.RFC3986.6"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-4.1">Section 4.1</a>&gt;
    817905  <a href="#uri" class="smpl">absolute-URI</a>  = &lt;absolute-URI, defined in <a href="#RFC3986" id="rfc.xref.RFC3986.7"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-4.3">Section 4.3</a>&gt;
    … …  
    826914 
    827915  <a href="#uri" class="smpl">partial-URI</a>   = relative-part [ "?" query ]
    828 </pre><p id="rfc.section.2.1.p.4">Each protocol element in HTTP that allows a URI reference will indicate in its ABNF production whether the element allows
     916</pre><p id="rfc.section.2.3.p.4">Each protocol element in HTTP that allows a URI reference will indicate in its ABNF production whether the element allows
    829917         only a URI in absolute form (absolute-URI), any relative reference (relative-ref), or some other subset of the URI-reference
    830918         grammar. Unless otherwise indicated, URI references are parsed relative to the request target (the default base URI for both
    831919         the request and its corresponding response).
    832920      </p>
    833       <h3 id="rfc.section.2.1.1"><a href="#rfc.section.2.1.1">2.1.1</a>&nbsp;<a id="http.uri" href="#http.uri">http URI scheme</a></h3>
     921      <h3 id="rfc.section.2.3.1"><a href="#rfc.section.2.3.1">2.3.1</a>&nbsp;<a id="http.uri" href="#http.uri">http URI scheme</a></h3>
    834922      <div id="rfc.iref.h.1"></div>
    835923      <div id="rfc.iref.u.1"></div>
    836       <p id="rfc.section.2.1.1.p.1">The "http" URI scheme is hereby defined for the purpose of minting identifiers according to their association with the hierarchical
     924      <p id="rfc.section.2.3.1.p.1">The "http" URI scheme is hereby defined for the purpose of minting identifiers according to their association with the hierarchical
    837925         namespace governed by a potential HTTP origin server listening for TCP connections on a given port. The HTTP server is identified
    838926         via the generic syntax's <a href="#uri" class="smpl">authority</a> component, which includes a host identifier and optional TCP port, and the remainder of the URI is considered to be identifying
    839927         data corresponding to a resource for which that server might provide an HTTP interface.
    840928      </p>
    841       <div id="rfc.figure.u.13"></div><pre class="inline"><span id="rfc.iref.g.30"></span>  <a href="#http.uri" class="smpl">http-URI</a> = "http:" "//" <a href="#uri" class="smpl">authority</a> <a href="#uri" class="smpl">path-abempty</a> [ "?" <a href="#uri" class="smpl">query</a> ]
    842 </pre><p id="rfc.section.2.1.1.p.3">The host identifier within an <a href="#uri" class="smpl">authority</a> component is defined in <a href="#RFC3986" id="rfc.xref.RFC3986.16"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-3.2.2">Section 3.2.2</a>. If host is provided as an IP literal or IPv4 address, then the HTTP server is any listener on the indicated TCP port at
     929      <div id="rfc.figure.u.17"></div><pre class="inline"><span id="rfc.iref.g.32"></span>  <a href="#http.uri" class="smpl">http-URI</a> = "http:" "//" <a href="#uri" class="smpl">authority</a> <a href="#uri" class="smpl">path-abempty</a> [ "?" <a href="#uri" class="smpl">query</a> ]
     930</pre><p id="rfc.section.2.3.1.p.3">The host identifier within an <a href="#uri" class="smpl">authority</a> component is defined in <a href="#RFC3986" id="rfc.xref.RFC3986.16"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-3.2.2">Section 3.2.2</a>. If host is provided as an IP literal or IPv4 address, then the HTTP server is any listener on the indicated TCP port at
    843931         that IP address. If host is a registered name, then that name is considered an indirect identifier and the recipient might
    844932         use a name resolution service, such as DNS, to find the address of a listener for that host. The host <em class="bcp14">MUST NOT</em> be empty; if an "http" URI is received with an empty host, then it <em class="bcp14">MUST</em> be rejected as invalid. If the port subcomponent is empty or not given, then TCP port 80 is assumed (the default reserved
    845933         port for WWW services).
    846934      </p>
    847       <p id="rfc.section.2.1.1.p.4">Regardless of the form of host identifier, access to that host is not implied by the mere presence of its name or address.
     935      <p id="rfc.section.2.3.1.p.4">Regardless of the form of host identifier, access to that host is not implied by the mere presence of its name or address.
    848936         The host may or may not exist and, even when it does exist, may or may not be running an HTTP server or listening to the indicated
    849937         port. The "http" URI scheme makes use of the delegated nature of Internet names and addresses to establish a naming authority
    … …  
    851939         which names are valid and how they might be used.
    852940      </p>
    853       <p id="rfc.section.2.1.1.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,
    854          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;5</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;6</a>, then that response is considered an authoritative answer to the client's request.
    855       </p>
    856       <p id="rfc.section.2.1.1.p.6">Although HTTP is independent of the transport protocol, the "http" scheme is specific to TCP-based services because the name
     941      <p id="rfc.section.2.3.1.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,
     942         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.
     943      </p>
     944      <p id="rfc.section.2.3.1.p.6">Although HTTP is independent of the transport protocol, the "http" scheme is specific to TCP-based services because the name
    857945         delegation process depends on TCP for establishing authority. An HTTP service based on some other underlying connection protocol
    858946         would presumably be identified using a different URI scheme, just as the "https" scheme (below) is used for servers that require
    … …  
    860948         --- it is only the authoritative interface used for mapping the namespace that is specific to TCP.
    861949      </p>
    862       <h3 id="rfc.section.2.1.2"><a href="#rfc.section.2.1.2">2.1.2</a>&nbsp;<a id="https.uri" href="#https.uri">https URI scheme</a></h3>
     950      <h3 id="rfc.section.2.3.2"><a href="#rfc.section.2.3.2">2.3.2</a>&nbsp;<a id="https.uri" href="#https.uri">https URI scheme</a></h3>
    863951      <div id="rfc.iref.h.2"></div>
    864952      <div id="rfc.iref.u.2"></div>
    865       <p id="rfc.section.2.1.2.p.1">The "https" URI scheme is hereby defined for the purpose of minting identifiers according to their association with the hierarchical
     953      <p id="rfc.section.2.3.2.p.1">The "https" URI scheme is hereby defined for the purpose of minting identifiers according to their association with the hierarchical
    866954         namespace governed by a potential HTTP origin server listening for SSL/TLS-secured connections on a given TCP port. The host
    867955         and port are determined in the same way as for the "http" scheme, except that a default TCP port of 443 is assumed if the
    868956         port subcomponent is empty or not given.
    869957      </p>
    870       <div id="rfc.figure.u.14"></div><pre class="inline"><span id="rfc.iref.g.31"></span>  <a href="#https.uri" class="smpl">https-URI</a> = "https:" "//" <a href="#uri" class="smpl">authority</a> <a href="#uri" class="smpl">path-abempty</a> [ "?" <a href="#uri" class="smpl">query</a> ]
    871 </pre><p id="rfc.section.2.1.2.p.3">The primary difference between the "http" and "https" schemes is that interaction with the latter is required to be secured
     958      <div id="rfc.figure.u.18"></div><pre class="inline"><span id="rfc.iref.g.33"></span>  <a href="#https.uri" class="smpl">https-URI</a> = "https:" "//" <a href="#uri" class="smpl">authority</a> <a href="#uri" class="smpl">path-abempty</a> [ "?" <a href="#uri" class="smpl">query</a> ]
     959</pre><p id="rfc.section.2.3.2.p.3">The primary difference between the "http" and "https" schemes is that interaction with the latter is required to be secured
    872960         for privacy through the use of strong encryption. The URI cannot be sent in a request until the connection is secure. Likewise,
    873961         the default for caching is that each response that would be considered "public" under the "http" scheme is instead treated
    874962         as "private" and thus not eligible for shared caching.
    875963      </p>
    876       <p id="rfc.section.2.1.2.p.4">The process for authoritative access to an "https" identified resource is defined in <a href="#RFC2818" id="rfc.xref.RFC2818.1"><cite title="HTTP Over TLS">[RFC2818]</cite></a>.
    877       </p>
    878       <h3 id="rfc.section.2.1.3"><a href="#rfc.section.2.1.3">2.1.3</a>&nbsp;<a id="uri.comparison" href="#uri.comparison">http and https URI Normalization and Comparison</a></h3>
    879       <p id="rfc.section.2.1.3.p.1">Since the "http" and "https" schemes conform to the URI generic syntax, such URIs are normalized and compared according to
     964      <p id="rfc.section.2.3.2.p.4">The process for authoritative access to an "https" identified resource is defined in <a href="#RFC2818" id="rfc.xref.RFC2818.1"><cite title="HTTP Over TLS">[RFC2818]</cite></a>.
     965      </p>
     966      <h3 id="rfc.section.2.3.3"><a href="#rfc.section.2.3.3">2.3.3</a>&nbsp;<a id="uri.comparison" href="#uri.comparison">http and https URI Normalization and Comparison</a></h3>
     967      <p id="rfc.section.2.3.3.p.1">Since the "http" and "https" schemes conform to the URI generic syntax, such URIs are normalized and compared according to
    880968         the algorithm defined in <a href="#RFC3986" id="rfc.xref.RFC3986.17"><cite title="Uniform Resource Identifier (URI): Generic Syntax">[RFC3986]</cite></a>, <a href="http://tools.ietf.org/html/rfc3986#section-6">Section 6</a>, using the defaults described above for each scheme.
    881969      </p>
    882       <p id="rfc.section.2.1.3.p.2">If the port is equal to the default port for a scheme, the normal form is to elide the port subcomponent. Likewise, an empty
     970      <p id="rfc.section.2.3.3.p.2">If the port is equal to the default port for a scheme, the normal form is to elide the port subcomponent. Likewise, an empty
    883971         path component is equivalent to an absolute path of "/", so the normal form is to provide a path of "/" instead. The scheme
    884972         and host are case-insensitive and normally provided in lowercase; all other components are compared in a case-sensitive manner.
    885973         Characters other than those in the "reserved" set are equivalent to their percent-encoded octets (see <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 normal form is to not encode them.
    886974      </p>
    887       <p id="rfc.section.2.1.3.p.3">For example, the following three URIs are equivalent:</p>
    888       <div id="rfc.figure.u.15"></div><pre class="text">   http://example.com:80/~smith/home.html
     975      <p id="rfc.section.2.3.3.p.3">For example, the following three URIs are equivalent:</p>
     976      <div id="rfc.figure.u.19"></div><pre class="text">   http://example.com:80/~smith/home.html
    889977   http://EXAMPLE.com/%7Esmith/home.html
    890978   http://EXAMPLE.com:/%7esmith/home.html
    891 </pre><p id="rfc.section.2.1.3.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"
    892          URI <em class="bcp14">MUST</em> be given as "/" when used as a request-target (<a href="#request-target" title="request-target">Section&nbsp;5.1.2</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.
    893       </p>
    894       <h3 id="rfc.section.2.1.4"><a href="#rfc.section.2.1.4">2.1.4</a>&nbsp;<a id="scheme.aliases" href="#scheme.aliases">Scheme aliases considered harmful</a></h3>
    895       <p id="rfc.section.2.1.4.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>
    896       </p>
    897       <h2 id="rfc.section.2.2"><a href="#rfc.section.2.2">2.2</a>&nbsp;<a id="intro.overall.operation" href="#intro.overall.operation">Overall Operation</a></h2>
    898       <p id="rfc.section.2.2.p.1">HTTP is a request/response protocol. A client sends a request to the server in the form of a request method, URI, and protocol
    899          version, followed by a MIME-like message containing request modifiers, client information, and possible body content over
    900          a connection with a server. The server responds with a status line, including the message's protocol version and a success
    901          or error code, followed by a MIME-like message containing server information, entity metadata, and possible entity-body content.
    902       </p>
    903       <p id="rfc.section.2.2.p.2">Most HTTP communication is initiated by a user agent and consists of a request to be applied to a resource via the HTTP interface
    904          provided by some origin server. In the simplest case, this may be accomplished via a single connection (v) between the user
    905          agent (UA) and the origin server (O).
    906       </p>
    907       <div id="rfc.figure.u.16"></div><pre class="drawing">       request chain ------------------------&gt;
    908     UA -------------------v------------------- O
    909        &lt;----------------------- response chain
    910 </pre><p id="rfc.section.2.2.p.4">A more complicated situation occurs when one or more intermediaries are present in the request/response chain. There are three
    911          common forms of intermediary: proxy, gateway, and tunnel. A proxy is a forwarding agent, receiving requests for a URI in its
    912          absolute form, rewriting all or part of the message, and forwarding the reformatted request toward the server identified by
    913          the URI. A gateway is a receiving agent, acting as a layer above some other server(s) and, if necessary, translating the requests
    914          to the underlying server's protocol. A tunnel acts as a relay point between two connections without changing the messages;
    915          tunnels are used when the communication needs to pass through an intermediary (such as a firewall) even when the intermediary
    916          cannot understand the contents of the messages.
    917       </p>
    918       <div id="rfc.figure.u.17"></div><pre class="drawing">       request chain --------------------------------------&gt;
    919     UA -----v----- A -----v----- B -----v----- C -----v----- O
    920        &lt;------------------------------------- response chain
    921 </pre><p id="rfc.section.2.2.p.6">The figure above shows three intermediaries (A, B, and C) between the user agent and origin server. A request or response
    922          message that travels the whole chain will pass through four separate connections. This distinction is important because some
    923          HTTP communication options may apply only to the connection with the nearest, non-tunnel neighbor, only to the end-points
    924          of the chain, or to all connections along the chain. Although the diagram is linear, each participant may be engaged in multiple,
    925          simultaneous communications. For example, B may be receiving requests from many clients other than A, and/or forwarding requests
    926          to servers other than C, at the same time that it is handling A's request.
    927       </p>
    928       <p id="rfc.section.2.2.p.7">Any party to the communication which is not acting as a tunnel may employ an internal cache for handling requests. The effect
    929          of a cache is that the request/response chain is shortened if one of the participants along the chain has a cached response
    930          applicable to that request. The following illustrates the resulting chain if B has a cached copy of an earlier response from
    931          O (via C) for a request which has not been cached by UA or A.
    932       </p>
    933       <div id="rfc.figure.u.18"></div><pre class="drawing">          request chain ----------&gt;
    934        UA -----v----- A -----v----- B - - - - - - C - - - - - - O
    935           &lt;--------- response chain
    936 </pre><p id="rfc.section.2.2.p.9">Not all responses are usefully cacheable, and some requests may contain modifiers which place special requirements on cache
    937          behavior. HTTP requirements for cache behavior and cacheable responses are defined in <a href="p6-cache.html#caching" title="Introduction">Section 1</a> of <a href="#Part6" id="rfc.xref.Part6.4"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>.
    938       </p>
    939       <p id="rfc.section.2.2.p.10">In fact, there are a wide variety of architectures and configurations of caches and proxies currently being experimented with
    940          or deployed across the World Wide Web. These systems include national hierarchies of proxy caches to save transoceanic bandwidth,
    941          systems that broadcast or multicast cache entries, organizations that distribute subsets of cached data via CD-ROM, and so
    942          on. HTTP systems are used in corporate intranets over high-bandwidth links, and for access via PDAs with low-power radio links
    943          and intermittent connectivity. The goal of HTTP/1.1 is to support the wide diversity of configurations already deployed while
    944          introducing protocol constructs that meet the needs of those who build web applications that require high reliability and,
    945          failing that, at least reliable indications of failure.
    946       </p>
    947       <p id="rfc.section.2.2.p.11">HTTP communication usually takes place over TCP/IP connections. The default port is TCP 80 (&lt;<a href="http://www.iana.org/assignments/port-numbers">http://www.iana.org/assignments/port-numbers</a>&gt;), but other ports can be used. This does not preclude HTTP from being implemented on top of any other protocol on the Internet,
    948          or on other networks. HTTP only presumes a reliable transport; any protocol that provides such guarantees can be used; the
    949          mapping of the HTTP/1.1 request and response structures onto the transport data units of the protocol in question is outside
    950          the scope of this specification.
    951       </p>
    952       <p id="rfc.section.2.2.p.12">In HTTP/1.0, most implementations used a new connection for each request/response exchange. In HTTP/1.1, a connection may
    953          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>).
    954       </p>
    955       <h2 id="rfc.section.2.3"><a href="#rfc.section.2.3">2.3</a>&nbsp;<a id="http.proxy" href="#http.proxy">Use of HTTP for proxy communication</a></h2>
    956       <p id="rfc.section.2.3.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>
    957       </p>
    958       <h2 id="rfc.section.2.4"><a href="#rfc.section.2.4">2.4</a>&nbsp;<a id="http.intercept" href="#http.intercept">Interception of HTTP for access control</a></h2>
    959       <p id="rfc.section.2.4.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>
    960       </p>
    961       <h2 id="rfc.section.2.5"><a href="#rfc.section.2.5">2.5</a>&nbsp;<a id="http.others" href="#http.others">Use of HTTP by other protocols</a></h2>
    962       <p id="rfc.section.2.5.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>
    963       </p>
    964       <h2 id="rfc.section.2.6"><a href="#rfc.section.2.6">2.6</a>&nbsp;<a id="http.media" href="#http.media">Use of HTTP by media type specification</a></h2>
    965       <p id="rfc.section.2.6.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>
    966       </p>
    967       <h1 id="rfc.section.3"><a href="#rfc.section.3">3.</a>&nbsp;<a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h1>
    968       <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a id="http.version" href="#http.version">HTTP Version</a></h2>
    969       <p id="rfc.section.3.1.p.1">HTTP uses a "&lt;major&gt;.&lt;minor&gt;" numbering scheme to indicate versions of the protocol. The protocol versioning policy is intended
    970          to allow the sender to indicate the format of a message and its capacity for understanding further HTTP communication, rather
    971          than the features obtained via that communication. No change is made to the version number for the addition of message components
    972          which do not affect communication behavior or which only add to extensible field values. The &lt;minor&gt; number is incremented
    973          when the changes made to the protocol add features which do not change the general message parsing algorithm, but which may
    974          add to the message semantics and imply additional capabilities of the sender. The &lt;major&gt; number is incremented when the format
    975          of a message within the protocol is changed. See <a href="#RFC2145" id="rfc.xref.RFC2145.1"><cite title="Use and Interpretation of HTTP Version Numbers">[RFC2145]</cite></a> for a fuller explanation.
    976       </p>
    977       <p id="rfc.section.3.1.p.2">The version of an HTTP message is indicated by an HTTP-Version field in the first line of the message. HTTP-Version is case-sensitive.</p>
    978       <div id="rfc.figure.u.19"></div><pre class="inline"><span id="rfc.iref.g.32"></span><span id="rfc.iref.g.33"></span>  <a href="#http.version" class="smpl">HTTP-Version</a>   = <a href="#http.version" class="smpl">HTTP-Prot-Name</a> "/" 1*<a href="#core.rules" class="smpl">DIGIT</a> "." 1*<a href="#core.rules" class="smpl">DIGIT</a>
    979   <a href="#http.version" class="smpl">HTTP-Prot-Name</a> = %x48.54.54.50 ; "HTTP", case-sensitive
    980 </pre><p id="rfc.section.3.1.p.4">Note that the major and minor numbers <em class="bcp14">MUST</em> be treated as separate integers and that each <em class="bcp14">MAY</em> be incremented higher than a single digit. Thus, HTTP/2.4 is a lower version than HTTP/2.13, which in turn is lower than HTTP/12.3.
    981          Leading zeros <em class="bcp14">MUST</em> be ignored by recipients and <em class="bcp14">MUST NOT</em> be sent.
    982       </p>
    983       <p id="rfc.section.3.1.p.5">An application that sends a request or response message that includes HTTP-Version of "HTTP/1.1" <em class="bcp14">MUST</em> be at least conditionally compliant with this specification. Applications that are at least conditionally compliant with this
    984          specification <em class="bcp14">SHOULD</em> use an HTTP-Version of "HTTP/1.1" in their messages, and <em class="bcp14">MUST</em> do so for any message that is not compatible with HTTP/1.0. For more details on when to send specific HTTP-Version values,
    985          see <a href="#RFC2145" id="rfc.xref.RFC2145.2"><cite title="Use and Interpretation of HTTP Version Numbers">[RFC2145]</cite></a>.
    986       </p>
    987       <p id="rfc.section.3.1.p.6">The HTTP version of an application is the highest HTTP version for which the application is at least conditionally compliant.</p>
    988       <p id="rfc.section.3.1.p.7">Proxy and gateway applications need to be careful when forwarding messages in protocol versions different from that of the
    989          application. Since the protocol version indicates the protocol capability of the sender, a proxy/gateway <em class="bcp14">MUST NOT</em> send a message with a version indicator which is greater than its actual version. If a higher version request is received,
    990          the proxy/gateway <em class="bcp14">MUST</em> either downgrade the request version, or respond with an error, or switch to tunnel behavior.
    991       </p>
    992       <p id="rfc.section.3.1.p.8">Due to interoperability problems with HTTP/1.0 proxies discovered since the publication of <a href="#RFC2068" id="rfc.xref.RFC2068.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a>, caching proxies <em class="bcp14">MUST</em>, gateways <em class="bcp14">MAY</em>, and tunnels <em class="bcp14">MUST NOT</em> upgrade the request to the highest version they support. The proxy/gateway's response to that request <em class="bcp14">MUST</em> be in the same major version as the request.
     979</pre><p id="rfc.section.2.3.3.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"
     980         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.
     981      </p>
     982      <h3 id="rfc.section.2.3.4"><a href="#rfc.section.2.3.4">2.3.4</a>&nbsp;<a id="scheme.aliases" href="#scheme.aliases">Scheme aliases considered harmful</a></h3>
     983      <p id="rfc.section.2.3.4.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>
     984      </p>
     985      <h2 id="rfc.section.2.4"><a href="#rfc.section.2.4">2.4</a>&nbsp;<a id="http.proxy" href="#http.proxy">Use of HTTP for proxy communication</a></h2>
     986      <p id="rfc.section.2.4.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>
     987      </p>
     988      <h2 id="rfc.section.2.5"><a href="#rfc.section.2.5">2.5</a>&nbsp;<a id="http.intercept" href="#http.intercept">Interception of HTTP for access control</a></h2>
     989      <p id="rfc.section.2.5.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>
     990      </p>
     991      <h2 id="rfc.section.2.6"><a href="#rfc.section.2.6">2.6</a>&nbsp;<a id="http.others" href="#http.others">Use of HTTP by other protocols</a></h2>
     992      <p id="rfc.section.2.6.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>
     993      </p>
     994      <h2 id="rfc.section.2.7"><a href="#rfc.section.2.7">2.7</a>&nbsp;<a id="http.media" href="#http.media">Use of HTTP by media type specification</a></h2>
     995      <p id="rfc.section.2.7.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>
     996      </p>
     997      <h1 id="rfc.section.3"><a href="#rfc.section.3">3.</a>&nbsp;<a id="http.message" href="#http.message">HTTP Message</a></h1>
     998      <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a id="message.types" href="#message.types">Message Types</a></h2>
     999      <p id="rfc.section.3.1.p.1">HTTP messages consist of requests from client to server and responses from server to client.</p>
     1000      <div id="rfc.figure.u.20"></div><pre class="inline"><span id="rfc.iref.g.34"></span>  <a href="#message.types" class="smpl">HTTP-message</a>   = <a href="#request" class="smpl">Request</a> / <a href="#response" class="smpl">Response</a>     ; HTTP/1.1 messages
     1001</pre><p id="rfc.section.3.1.p.3">Request (<a href="#request" title="Request">Section&nbsp;4</a>) and Response (<a href="#response" title="Response">Section&nbsp;5</a>) messages use the generic message format of <a href="#RFC5322" id="rfc.xref.RFC5322.2"><cite title="Internet Message Format">[RFC5322]</cite></a> for transferring entities (the payload of the message). Both types of message consist of a start-line, zero or more header
     1002         fields (also known as "headers"), an empty line (i.e., a line with nothing preceding the CRLF) indicating the end of the header
     1003         fields, and possibly a message-body.
     1004      </p>
     1005      <div id="rfc.figure.u.21"></div><pre class="inline"><span id="rfc.iref.g.35"></span><span id="rfc.iref.g.36"></span>  <a href="#message.types" class="smpl">generic-message</a> = <a href="#message.types" class="smpl">start-line</a>
     1006                    *( <a href="#message.headers" class="smpl">message-header</a> <a href="#core.rules" class="smpl">CRLF</a> )
     1007                    <a href="#core.rules" class="smpl">CRLF</a>
     1008                    [ <a href="#message.body" class="smpl">message-body</a> ]
     1009  <a href="#message.types" class="smpl">start-line</a>      = <a href="#request-line" class="smpl">Request-Line</a> / <a href="#status-line" class="smpl">Status-Line</a>
     1010</pre><p id="rfc.section.3.1.p.5">In the interest of robustness, servers <em class="bcp14">SHOULD</em> ignore any empty line(s) received where a Request-Line is expected. In other words, if the server is reading the protocol
     1011         stream at the beginning of a message and receives a CRLF first, it should ignore the CRLF.
     1012      </p>
     1013      <p id="rfc.section.3.1.p.6">Certain buggy HTTP/1.0 client implementations generate extra CRLF's after a POST request. To restate what is explicitly forbidden
     1014         by the BNF, an HTTP/1.1 client <em class="bcp14">MUST NOT</em> preface or follow a request with an extra CRLF.
     1015      </p>
     1016      <p id="rfc.section.3.1.p.7">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
     1017         implementation of HTTP into ignoring that field or processing the next line as a new request, either of which may result in
     1018         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.
     1019      </p>
     1020      <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a>&nbsp;<a id="message.headers" href="#message.headers">Message Headers</a></h2>
     1021      <p id="rfc.section.3.2.p.1">HTTP header fields follow the same general format as Internet messages in <a href="http://tools.ietf.org/html/rfc5322#section-2.1">Section 2.1</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.3"><cite title="Internet Message Format">[RFC5322]</cite></a>. Each header field consists of a name followed by a colon (":"), optional whitespace, and the field value. Field names are
     1022         case-insensitive.
     1023      </p>
     1024      <div id="rfc.figure.u.22"></div><pre class="inline"><span id="rfc.iref.g.37"></span><span id="rfc.iref.g.38"></span><span id="rfc.iref.g.39"></span><span id="rfc.iref.g.40"></span>  <a href="#message.headers" class="smpl">message-header</a> = <a href="#message.headers" class="smpl">field-name</a> ":" OWS [ <a href="#message.headers" class="smpl">field-value</a> ] OWS
     1025  <a href="#message.headers" class="smpl">field-name</a>     = <a href="#rule.token.separators" class="smpl">token</a>
     1026  <a href="#message.headers" class="smpl">field-value</a>    = *( <a href="#message.headers" class="smpl">field-content</a> / <a href="#rule.whitespace" class="smpl">OWS</a> )
     1027  <a href="#message.headers" 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> )
     1028</pre><p id="rfc.section.3.2.p.3">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 (allowing other character sets 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 charset <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> constrain their field-values to US-ASCII characters. Recipients <em class="bcp14">SHOULD</em> treat other (obs-text) octets in field-content as opaque data.
     1029      </p>
     1030      <p id="rfc.section.3.2.p.4">No whitespace is allowed between the header field-name and colon. For security reasons, any request message received containing
     1031         such whitespace <em class="bcp14">MUST</em> be rejected with a response code of 400 (Bad Request) and any such whitespace in a response message <em class="bcp14">MUST</em> be removed.
     1032      </p>
     1033      <p id="rfc.section.3.2.p.5">The field value <em class="bcp14">MAY</em> be preceded by optional whitespace; a single SP is preferred. The field-value does not include any leading or trailing white
     1034         space: OWS occurring before the first non-whitespace character of the field-value or after the last non-whitespace character
     1035         of the field-value is ignored and <em class="bcp14">MAY</em> be removed without changing the meaning of the header field.
     1036      </p>
     1037      <p id="rfc.section.3.2.p.6">Historically, HTTP header field values could be extended over multiple lines by preceding each extra line with at least one
     1038         space or horizontal tab character (line folding). This specification deprecates such line folding except within the message/http
     1039         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
     1040         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
     1041         forwarding the message downstream.
     1042      </p>
     1043      <div id="rule.comment">
     1044         <p id="rfc.section.3.2.p.7">    Comments can be included in some HTTP header fields by surrounding the comment text with parentheses. Comments are only allowed
     1045            in fields containing "comment" as part of their field value definition. In all other fields, parentheses are considered part
     1046            of the field value.
     1047         </p>
     1048      </div>
     1049      <div id="rfc.figure.u.23"></div><pre class="inline"><span id="rfc.iref.g.41"></span><span id="rfc.iref.g.42"></span>  <a href="#rule.comment" class="smpl">comment</a>        = "(" *( <a href="#rule.comment" class="smpl">ctext</a> / <a href="#rule.quoted-pair" class="smpl">quoted-pair</a> / <a href="#rule.comment" class="smpl">comment</a> ) ")"
     1050  <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>
     1051                 ; <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>
     1052</pre><p id="rfc.section.3.2.p.9">The order in which header fields with differing field names are received is not significant. However, it is "good practice"
     1053         to send general-header fields first, followed by request-header or response-header fields, and ending with the entity-header
     1054         fields.
     1055      </p>
     1056      <p id="rfc.section.3.2.p.10">Multiple message-header fields with the same field-name <em class="bcp14">MAY</em> be present in a message if and only if the entire field-value for that header field is defined as a comma-separated list [i.e.,
     1057         #(values)]. It <em class="bcp14">MUST</em> be possible to combine the multiple header fields into one "field-name: field-value" pair, without changing the semantics
     1058         of the message, by appending each subsequent field-value to the first, each separated by a comma. The order in which header
     1059         fields with the same field-name are received is therefore significant to the interpretation of the combined field value, and
     1060         thus a proxy <em class="bcp14">MUST NOT</em> change the order of these field values when a message is forwarded.
    9931061      </p>
    9941062      <div class="note">
    995          <p> <b>Note:</b> Converting between versions of HTTP may involve modification of header fields required or forbidden by the versions involved.
     1063         <p> <b>Note:</b> the "Set-Cookie" header as implemented in practice (as opposed to how it is specified in <a href="#RFC2109" id="rfc.xref.RFC2109.1"><cite title="HTTP State Management Mechanism">[RFC2109]</cite></a>) can occur multiple times, but does not use the list syntax, and thus cannot be combined into a single line. (See Appendix
     1064            A.2.3 of <a href="#Kri2001" id="rfc.xref.Kri2001.1"><cite title="HTTP Cookies: Standards, Privacy, and Politics">[Kri2001]</cite></a> for details.) Also note that the Set-Cookie2 header specified in <a href="#RFC2965" id="rfc.xref.RFC2965.1"><cite title="HTTP State Management Mechanism">[RFC2965]</cite></a> does not share this problem.
    9961065         </p>
    9971066      </div>
    998       <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a>&nbsp;<a id="date.time.formats.full.date" href="#date.time.formats.full.date">Date/Time Formats: Full Date</a></h2>
    999       <p id="rfc.section.3.2.p.1">HTTP applications have historically allowed three different formats for the representation of date/time stamps:</p>
    1000       <div id="rfc.figure.u.20"></div><pre class="text">  Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
     1067      <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>
     1068      <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
     1069         message-body differs from the entity-body only when a transfer-coding has been applied, as indicated by the Transfer-Encoding
     1070         header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.1" title="Transfer-Encoding">Section&nbsp;8.7</a>).
     1071      </p>
     1072      <div id="rfc.figure.u.24"></div><pre class="inline"><span id="rfc.iref.g.43"></span>  <a href="#message.body" class="smpl">message-body</a> = <a href="#abnf.dependencies" class="smpl">entity-body</a>
     1073               / &lt;entity-body encoded as per <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding</a>&gt;
     1074</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
     1075         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.)
     1076      </p>
     1077      <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>
     1078      <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
     1079         in the request's message-headers. When a request message contains both a message-body of non-zero length and a method that
     1080         does 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
     1081         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.
     1082      </p>
     1083      <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
     1084         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),
     1085         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.
     1086      </p>
     1087      <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>
     1088      <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
     1089         have been applied. When a message-body is included with a message, the transfer-length of that body is determined by one of
     1090         the following (in order of precedence):
     1091      </p>
     1092      <p id="rfc.section.3.4.p.2"> </p>
     1093      <ol>
     1094         <li>
     1095            <p>Any response message which "<em class="bcp14">MUST NOT</em>" include a message-body (such as the 1xx, 204, and 304 responses and any response to a HEAD request) is always terminated
     1096               by the first empty line after the header fields, regardless of the entity-header fields present in the message.
     1097            </p>
     1098         </li>
     1099         <li>
     1100            <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
     1101               and the "chunked" transfer-coding is not present, the transfer-length is defined by the sender closing the connection.
     1102            </p>
     1103         </li>
     1104         <li>
     1105            <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
     1106               with both a Transfer-Encoding header field and a Content-Length header field, the latter <em class="bcp14">MUST</em> be ignored.
     1107            </p>
     1108         </li>
     1109         <li>
     1110            <p>If the message uses the media type "multipart/byteranges", and the transfer-length is not otherwise specified, then this self-delimiting
     1111               media type defines the transfer-length. This media type <em class="bcp14">MUST NOT</em> be used unless the sender knows that the recipient can parse it; the presence in a request of a Range header with multiple
     1112               byte-range specifiers from a 1.1 client implies that the client can parse multipart/byteranges responses.
     1113            </p>
     1114            <dl class="empty">
     1115               <dd>A range header might be forwarded by a 1.0 proxy that does not understand multipart/byteranges; in this case the server <em class="bcp14">MUST</em> delimit the message using methods defined in items 1, 3 or 5 of this section.
     1116               </dd>
     1117            </dl>
     1118         </li>
     1119         <li>
     1120            <p>By the server closing the connection. (Closing the connection cannot be used to indicate the end of a request body, since
     1121               that would leave no possibility for the server to send back a response.)
     1122            </p>
     1123         </li>
     1124      </ol>
     1125      <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
     1126         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
     1127         to insist on receiving a valid Content-Length.
     1128      </p>
     1129      <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.
     1130      </p>
     1131      <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.
     1132      </p>
     1133      <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.
     1134      </p>
     1135      <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>
     1136      <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
     1137         to the entity being transferred. These header fields apply only to the message being transmitted.
     1138      </p>
     1139      <div id="rfc.figure.u.25"></div><pre class="inline"><span id="rfc.iref.g.44"></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>
     1140                 / <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>
     1141                 / <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>
     1142                 / <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>
     1143                 / <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>
     1144                 / <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>
     1145                 / <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>
     1146                 / <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>
     1147                 / <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>
     1148</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
     1149         or experimental header fields may be given the semantics of general header fields if all parties in the communication recognize
     1150         them to be general-header fields. Unrecognized header fields are treated as entity-header fields.
     1151      </p>
     1152      <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="request" href="#request">Request</a></h1>
     1153      <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
     1154         resource, the identifier of the resource, and the protocol version in use.
     1155      </p>
     1156      <div id="rfc.figure.u.26"></div><pre class="inline"><span id="rfc.iref.g.45"></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>
     1157                  *(( <a href="#general.header.fields" class="smpl">general-header</a>        ; <a href="#general.header.fields" title="General Header Fields">Section&nbsp;3.5</a>
     1158                   / <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>
     1159                   / <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>
     1160                  <a href="#core.rules" class="smpl">CRLF</a>
     1161                  [ <a href="#message.body" class="smpl">message-body</a> ]          ; <a href="#message.body" title="Message Body">Section&nbsp;3.3</a>
     1162</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>
     1163      <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.
     1164         The elements are separated by SP characters. No CR or LF is allowed except in the final CRLF sequence.
     1165      </p>
     1166      <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.46"></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>
     1167</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>
     1168      <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>
     1169      <div id="rfc.figure.u.28"></div><pre class="inline"><span id="rfc.iref.g.47"></span><span id="rfc.iref.g.48"></span>  <a href="#method" class="smpl">Method</a>         = <a href="#rule.token.separators" class="smpl">token</a>
     1170</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>
     1171      <p id="rfc.section.4.1.2.p.1">The request-target identifies the resource upon which to apply the request.</p>
     1172      <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.49"></span>  <a href="#request-target" class="smpl">request-target</a> = "*"
     1173                 / <a href="#uri" class="smpl">absolute-URI</a>
     1174                 / ( <a href="#uri" class="smpl">path-absolute</a> [ "?" <a href="#uri" class="smpl">query</a> ] )
     1175                 / <a href="#uri" class="smpl">authority</a>
     1176</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
     1177         not apply to a particular resource, but to the server itself, and is only allowed when the method used does not necessarily
     1178         apply to a resource. One example would be
     1179      </p>
     1180      <div id="rfc.figure.u.30"></div><pre class="text">  OPTIONS * HTTP/1.1
     1181</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,
     1182         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
     1183         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
     1184         Request-Line would be:
     1185      </p>
     1186      <div id="rfc.figure.u.31"></div><pre class="text">  GET http://www.example.org/pub/WWW/TheProject.html HTTP/1.1
     1187</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.
     1188      </p>
     1189      <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>).
     1190      </p>
     1191      <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
     1192         absolute path of the URI <em class="bcp14">MUST</em> be transmitted (see <a href="#http.uri" title="http URI scheme">Section&nbsp;2.3.1</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
     1193         server would create a TCP connection to port 80 of the host "www.example.org" and send the lines:
     1194      </p>
     1195      <div id="rfc.figure.u.32"></div><pre class="text">  GET /pub/WWW/TheProject.html HTTP/1.1
     1196  Host: www.example.org
     1197</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
     1198         URI, it <em class="bcp14">MUST</em> be given as "/" (the server root).
     1199      </p>
     1200      <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
     1201         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.
     1202      </p>
     1203      <div id="rfc.figure.u.33"></div>
     1204      <p>For example, the request</p><pre class="text">  OPTIONS http://www.example.org:8001 HTTP/1.1
     1205</pre><div id="rfc.figure.u.34"></div>
     1206      <p>would be forwarded by the proxy as</p><pre class="text">  OPTIONS * HTTP/1.1
     1207  Host: www.example.org:8001
     1208</pre>  <p>after connecting to port 8001 of host "www.example.org".</p>
     1209      <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;2.3.1</a>. If the request-target is percent-encoded (<a href="#RFC3986" id="rfc.xref.RFC3986.19"><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.
     1210      </p>
     1211      <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
     1212         above to replace a null path-absolute with "/".
     1213      </p>
     1214      <div class="note">
     1215         <p> <b>Note:</b> The "no rewrite" rule prevents the proxy from changing the meaning of the request when the origin server is improperly using
     1216            a non-reserved URI character for a reserved purpose. Implementors should be aware that some pre-HTTP/1.1 proxies have been
     1217            known to rewrite the request-target.
     1218         </p>
     1219      </div>
     1220      <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
     1221         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>).
     1222      </p>
     1223      <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.
     1224      </p>
     1225      <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>
     1226      <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
     1227         field.
     1228      </p>
     1229      <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.)
     1230      </p>
     1231      <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
     1232         vanity host names) <em class="bcp14">MUST</em> use the following rules for determining the requested resource on an HTTP/1.1 request:
     1233      </p>
     1234      <ol>
     1235         <li>If request-target is an absolute-URI, the host is part of the request-target. Any Host header field value in the request <em class="bcp14">MUST</em> be ignored.
     1236         </li>
     1237         <li>If the request-target is not an absolute-URI, and the request includes a Host header field, the host is determined by the
     1238            Host header field value.
     1239         </li>
     1240         <li>If the host as determined by rule 1 or 2 is not a valid host on the server, the response <em class="bcp14">MUST</em> be a 400 (Bad Request) error message.
     1241         </li>
     1242      </ol>
     1243      <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
     1244         what exact resource is being requested.
     1245      </p>
     1246      <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="response" href="#response">Response</a></h1>
     1247      <p id="rfc.section.5.p.1">After receiving and interpreting a request message, a server responds with an HTTP response message.</p>
     1248      <div id="rfc.figure.u.35"></div><pre class="inline"><span id="rfc.iref.g.50"></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>
     1249                  *(( <a href="#general.header.fields" class="smpl">general-header</a>        ; <a href="#general.header.fields" title="General Header Fields">Section&nbsp;3.5</a>
     1250                   / <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>
     1251                   / <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>
     1252                  <a href="#core.rules" class="smpl">CRLF</a>
     1253                  [ <a href="#message.body" class="smpl">message-body</a> ]          ; <a href="#message.body" title="Message Body">Section&nbsp;3.3</a>
     1254</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>
     1255      <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
     1256         and its associated textual phrase, with each element separated by SP characters. No CR or LF is allowed except in the final
     1257         CRLF sequence.
     1258      </p>
     1259      <div id="rfc.figure.u.36"></div><pre class="inline"><span id="rfc.iref.g.51"></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>
     1260</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>
     1261      <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
     1262         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,
     1263         out of deference to earlier Internet application protocols that were more frequently used with interactive text clients. A
     1264         client <em class="bcp14">SHOULD</em> ignore the content of the Reason Phrase.
     1265      </p>
     1266      <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.
     1267         There are 5 values for the first digit:
     1268      </p>
     1269      <ul>
     1270         <li>1xx: Informational - Request received, continuing process</li>
     1271         <li>2xx: Success - The action was successfully received, understood, and accepted</li>
     1272         <li>3xx: Redirection - Further action must be taken in order to complete the request</li>
     1273         <li>4xx: Client Error - The request contains bad syntax or cannot be fulfilled</li>
     1274         <li>5xx: Server Error - The server failed to fulfill an apparently valid request</li>
     1275      </ul>
     1276      <div id="rfc.figure.u.37"></div><pre class="inline"><span id="rfc.iref.g.52"></span><span id="rfc.iref.g.53"></span><span id="rfc.iref.g.54"></span>  <a href="#status.code.and.reason.phrase" class="smpl">Status-Code</a>    = 3<a href="#core.rules" class="smpl">DIGIT</a>
     1277  <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> )
     1278</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>
     1279      <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>
     1280      <p id="rfc.section.6.1.p.1">HTTP applications have historically allowed three different formats for the representation of date/time stamps:</p>
     1281      <div id="rfc.figure.u.38"></div><pre class="text">  Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
    10011282  Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format
    10021283  Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format
    1003 </pre><p id="rfc.section.3.2.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
     1284</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
    10041285         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.
    10051286      </p>
    1006       <p id="rfc.section.3.2.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
     1287      <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
    10071288         Universal Time). This is indicated in the first two formats by the inclusion of "GMT" as the three-letter abbreviation for
    10081289         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.
    10091290      </p>
    1010       <div id="rfc.figure.u.21"></div><pre class="inline"><span id="rfc.iref.g.34"></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>
     1291      <div id="rfc.figure.u.39"></div><pre class="inline"><span id="rfc.iref.g.55"></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>
    10111292</pre><div id="preferred.date.format">
    1012          <p id="rfc.section.3.2.p.6">                    Preferred format:</p>
     1293         <p id="rfc.section.6.1.p.6">                    Preferred format:</p>
    10131294      </div>
    1014       <div id="rfc.figure.u.22"></div><pre class="inline"><span id="rfc.iref.g.35"></span><span id="rfc.iref.g.36"></span><span id="rfc.iref.g.37"></span><span id="rfc.iref.g.38"></span><span id="rfc.iref.g.39"></span><span id="rfc.iref.g.40"></span><span id="rfc.iref.g.41"></span><span id="rfc.iref.g.42"></span><span id="rfc.iref.g.43"></span><span id="rfc.iref.g.44"></span><span id="rfc.iref.g.45"></span><span id="rfc.iref.g.46"></span>  <a href="#preferred.date.format" class="smpl">rfc1123-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> "," <a href="#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>
     1295      <div id="rfc.figure.u.40"></div><pre class="inline"><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><span id="rfc.iref.g.67"></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>
    10151296
    10161297  <a href="#preferred.date.format" class="smpl">day-name</a>     = %x4D.6F.6E ; "Mon", case-sensitive
    … …  
    10481329  <a href="#preferred.date.format" class="smpl">minute</a>       = 2<a href="#core.rules" class="smpl">DIGIT</a>               
    10491330  <a href="#preferred.date.format" class="smpl">second</a>       = 2<a href="#core.rules" class="smpl">DIGIT</a>               
    1050 </pre><p id="rfc.section.3.2.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.RFC5322.2"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.3">Section 3.3</a>).
     1331</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.RFC5322.4"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.3">Section 3.3</a>).
    10511332      </p>
    10521333      <div id="obsolete.date.formats">
    1053          <p id="rfc.section.3.2.p.9">                Obsolete formats:</p>
     1334         <p id="rfc.section.6.1.p.9">                Obsolete formats:</p>
    10541335      </div>
    1055       <div id="rfc.figure.u.23"></div><pre class="inline"><span id="rfc.iref.g.47"></span>  <a href="#obsolete.date.formats" class="smpl">obs-date</a>     = <a href="#obsolete.date.formats" class="smpl">rfc850-date</a> / <a href="#obsolete.date.formats" class="smpl">asctime-date</a>
    1056 </pre><div id="rfc.figure.u.24"></div><pre class="inline"><span id="rfc.iref.g.48"></span>  <a href="#obsolete.date.formats" class="smpl">rfc850-date</a>  = <a href="#obsolete.date.formats" class="smpl">day-name-l</a> "," <a href="#core.rules" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date2</a> <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>
     1336      <div id="rfc.figure.u.41"></div><pre class="inline"><span id="rfc.iref.g.68"></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>
     1337</pre><div id="rfc.figure.u.42"></div><pre class="inline"><span id="rfc.iref.g.69"></span>  <a href="#obsolete.date.formats" class="smpl">rfc850-date</a>  = <a href="#obsolete.date.formats" class="smpl">day-name-l</a> "," <a href="#core.rules" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date2</a> <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>
    10571338  <a href="#obsolete.date.formats" class="smpl">date2</a>        = <a href="#preferred.date.format" class="smpl">day</a> "-" <a href="#preferred.date.format" class="smpl">month</a> "-" 2<a href="#core.rules" class="smpl">DIGIT</a>
    10581339                 ; day-month-year (e.g., 02-Jun-82)
    … …  
    10651346         / %x53.61.74.75.72.64.61.79 ; "Saturday", case-sensitive
    10661347         / %x53.75.6E.64.61.79 ; "Sunday", case-sensitive
    1067 </pre><div id="rfc.figure.u.25"></div><pre class="inline"><span id="rfc.iref.g.49"></span>  <a href="#obsolete.date.formats" class="smpl">asctime-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> <a href="#core.rules" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date3</a> <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">year</a>
     1348</pre><div id="rfc.figure.u.43"></div><pre class="inline"><span id="rfc.iref.g.70"></span>  <a href="#obsolete.date.formats" class="smpl">asctime-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> <a href="#core.rules" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date3</a> <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">year</a>
    10681349  <a href="#obsolete.date.formats" class="smpl">date3</a>        = <a href="#preferred.date.format" class="smpl">month</a> <a href="#core.rules" class="smpl">SP</a> ( 2<a href="#core.rules" class="smpl">DIGIT</a> / ( <a href="#core.rules" class="smpl">SP</a> 1<a href="#core.rules" class="smpl">DIGIT</a> ))
    10691350                 ; month day (e.g., Jun  2)
    … …  
    10781359         </p>
    10791360      </div>
    1080       <h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="transfer.codings" href="#transfer.codings">Transfer Codings</a></h2>
    1081       <p id="rfc.section.3.3.p.1">Transfer-coding values are used to indicate an encoding transformation that has been, can be, or may need to be applied to
     1361      <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>
     1362      <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
    10821363         an entity-body in order to ensure "safe transport" through the network. This differs from a content coding in that the transfer-coding
    10831364         is a property of the message, not of the original entity.
    10841365      </p>
    1085       <div id="rfc.figure.u.26"></div><pre class="inline"><span id="rfc.iref.g.50"></span><span id="rfc.iref.g.51"></span>  <a href="#transfer.codings" class="smpl">transfer-coding</a>         = "chunked" / <a href="#transfer.codings" class="smpl">transfer-extension</a>
     1366      <div id="rfc.figure.u.44"></div><pre class="inline"><span id="rfc.iref.g.71"></span><span id="rfc.iref.g.72"></span>  <a href="#transfer.codings" class="smpl">transfer-coding</a>         = "chunked" / <a href="#transfer.codings" class="smpl">transfer-extension</a>
    10861367  <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> )
    10871368</pre><div id="rule.parameter">
    1088          <p id="rfc.section.3.3.p.3">      Parameters are in the form of attribute/value pairs.</p>
     1369         <p id="rfc.section.6.2.p.3">      Parameters are in the form of attribute/value pairs.</p>
    10891370      </div>
    1090       <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.52"></span><span id="rfc.iref.g.53"></span><span id="rfc.iref.g.54"></span><span id="rfc.iref.g.55"></span><span id="rfc.iref.g.56"></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>
     1371      <div id="rfc.figure.u.45"></div><pre class="inline"><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><span id="rfc.iref.g.77"></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>
    10911372  <a href="#rule.parameter" class="smpl">attribute</a>               = <a href="#rule.token.separators" class="smpl">token</a>
    10921373  <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>
    1093 </pre><p id="rfc.section.3.3.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.1" title="Transfer-Encoding">Section&nbsp;8.7</a>).
    1094       </p>
    1095       <p id="rfc.section.3.3.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
     1374</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>).
     1375      </p>
     1376      <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
    10961377         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
    1097          (<a href="#message.length" title="Message Length">Section&nbsp;4.4</a>).
    1098       </p>
    1099       <p id="rfc.section.3.3.p.7">Transfer-codings are analogous to the Content-Transfer-Encoding values of MIME <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>, which were designed to enable safe transport of binary data over a 7-bit transport service. However, safe transport has
     1378         (<a href="#message.length" title="Message Length">Section&nbsp;3.4</a>).
     1379      </p>
     1380      <p id="rfc.section.6.2.p.7">Transfer-codings are analogous to the Content-Transfer-Encoding values of MIME <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>, which were designed to enable safe transport of binary data over a 7-bit transport service. However, safe transport has
    11001381         a different focus for an 8bit-clean transfer protocol. In HTTP, the only unsafe characteristic of message-bodies is the difficulty
    1101          in determining the exact body length (<a href="#message.length" title="Message Length">Section&nbsp;4.4</a>), or the desire to encrypt data over a shared transport.
    1102       </p>
    1103       <p id="rfc.section.3.3.p.8">The Internet Assigned Numbers Authority (IANA) acts as a registry for transfer-coding value tokens. Initially, the registry
    1104          contains the following tokens: "chunked" (<a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;3.3.1</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.Part3.5"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>).
    1105       </p>
    1106       <p id="rfc.section.3.3.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.Part3.6"><cite title="HTTP/1.1, part 3: Message Payload and Content Negotiation">[Part3]</cite></a>).
    1107       </p>
    1108       <p id="rfc.section.3.3.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.
    1109       </p>
    1110       <h3 id="rfc.section.3.3.1"><a href="#rfc.section.3.3.1">3.3.1</a>&nbsp;<a id="chunked.transfer.encoding" href="#chunked.transfer.encoding">Chunked Transfer Coding</a></h3>
    1111       <p id="rfc.section.3.3.1.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
     1382         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.
     1383      </p>
     1384      <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
     1385         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>).
     1386      </p>
     1387      <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>).
     1388      </p>
     1389      <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.
     1390      </p>
     1391      <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>
     1392      <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
    11121393         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
    11131394         necessary for the recipient to verify that it has received the full message.
    11141395      </p>
    1115       <div id="rfc.figure.u.28"></div><pre class="inline"><span id="rfc.iref.g.57"></span><span id="rfc.iref.g.58"></span><span id="rfc.iref.g.59"></span><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>  <a href="#chunked.transfer.encoding" class="smpl">Chunked-Body</a>   = *<a href="#chunked.transfer.encoding" class="smpl">chunk</a>
     1396      <div id="rfc.figure.u.46"></div><pre class="inline"><span id="rfc.iref.g.78"></span><span id="rfc.iref.g.79"></span><span id="rfc.iref.g.80"></span><span id="rfc.iref.g.81"></span><span id="rfc.iref.g.82"></span><span id="rfc.iref.g.83"></span><span id="rfc.iref.g.84"></span><span id="rfc.iref.g.85"></span><span id="rfc.iref.g.86"></span>  <a href="#chunked.transfer.encoding" class="smpl">Chunked-Body</a>   = *<a href="#chunked.transfer.encoding" class="smpl">chunk</a>
    11161397                   <a href="#chunked.transfer.encoding" class="smpl">last-chunk</a>
    11171398                   <a href="#chunked.transfer.encoding" class="smpl">trailer-part</a>
    … …  
    11291410  <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
    11301411  <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> )
    1131 </pre><p id="rfc.section.3.3.1.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
     1412</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
    11321413         by any chunk whose size is zero, followed by the trailer, which is terminated by an empty line.
    11331414      </p>
    1134       <p id="rfc.section.3.3.1.p.4">The trailer allows the sender to include additional HTTP header fields at the end of the message. The Trailer header field
    1135          can be used to indicate which header fields are included in a trailer (see <a href="#header.trailer" id="rfc.xref.header.trailer.1" title="Trailer">Section&nbsp;8.6</a>).
    1136       </p>
    1137       <p id="rfc.section.3.3.1.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:
     1415      <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
     1416         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>).
     1417      </p>
     1418      <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:
    11381419      </p>
    11391420      <ol>
    … …  
    11461427         </li>
    11471428      </ol>
    1148       <p id="rfc.section.3.3.1.p.6">This requirement prevents an interoperability failure when the message is being received by an HTTP/1.1 (or later) proxy and
     1429      <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
    11491430         forwarded to an HTTP/1.0 recipient. It avoids a situation where compliance with the protocol would have necessitated a possibly
    11501431         infinite buffer on the proxy.
    11511432      </p>
    1152       <p id="rfc.section.3.3.1.p.7">A process for decoding the "chunked" transfer-coding can be represented in pseudo-code as:</p>
    1153       <div id="rfc.figure.u.29"></div><pre class="text">  length := 0
     1433      <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>
     1434      <div id="rfc.figure.u.47"></div><pre class="text">  length := 0
    11541435  read chunk-size, chunk-ext (if any) and CRLF
    11551436  while (chunk-size &gt; 0) {
    … …  
    11661447  Content-Length := length
    11671448  Remove "chunked" from Transfer-Encoding
    1168 </pre><p id="rfc.section.3.3.1.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.
    1169       </p>
    1170       <h2 id="rfc.section.3.4"><a href="#rfc.section.3.4">3.4</a>&nbsp;<a id="product.tokens" href="#product.tokens">Product Tokens</a></h2>
    1171       <p id="rfc.section.3.4.p.1">Product tokens are used to allow communicating applications to identify themselves by software name and version. Most fields
     1449</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.
     1450      </p>
     1451      <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>
     1452      <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
    11721453         using product tokens also allow sub-products which form a significant part of the application to be listed, separated by whitespace.
    11731454         By convention, the products are listed in order of their significance for identifying the application.
    11741455      </p>
    1175       <div id="rfc.figure.u.30"></div><pre class="inline"><span id="rfc.iref.g.66"></span><span id="rfc.iref.g.67"></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>]
     1456      <div id="rfc.figure.u.48"></div><pre class="inline"><span id="rfc.iref.g.87"></span><span id="rfc.iref.g.88"></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>]
    11761457  <a href="#product.tokens" class="smpl">product-version</a> = <a href="#rule.token.separators" class="smpl">token</a>
    1177 </pre><p id="rfc.section.3.4.p.3">Examples:</p>
    1178       <div id="rfc.figure.u.31"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
     1458</pre><p id="rfc.section.6.3.p.3">Examples:</p>
     1459      <div id="rfc.figure.u.49"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
    11791460  Server: Apache/0.8.4
    1180 </pre><p id="rfc.section.3.4.p.5">Product tokens <em class="bcp14">SHOULD</em> be short and to the point. They <em class="bcp14">MUST NOT</em> be used for advertising or other non-essential information. Although any token 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).
    1181       </p>
    1182       <h2 id="rfc.section.3.5"><a href="#rfc.section.3.5">3.5</a>&nbsp;<a id="quality.values" href="#quality.values">Quality Values</a></h2>
    1183       <p id="rfc.section.3.5.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.Part3.7"><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
     1461</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).
     1462      </p>
     1463      <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>
     1464      <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
    11841465         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
    11851466         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.
    11861467      </p>
    1187       <div id="rfc.figure.u.32"></div><pre class="inline"><span id="rfc.iref.g.68"></span>  <a href="#quality.values" class="smpl">qvalue</a>         = ( "0" [ "." 0*3<a href="#core.rules" class="smpl">DIGIT</a> ] )
     1468      <div id="rfc.figure.u.50"></div><pre class="inline"><span id="rfc.iref.g.89"></span>  <a href="#quality.values" class="smpl">qvalue</a>         = ( "0" [ "." 0*3<a href="#core.rules" class="smpl">DIGIT</a> ] )
    11881469                 / ( "1" [ "." 0*3("0") ] )
    11891470</pre><div class="note">
    … …  
    11911472         </p>
    11921473      </div>
    1193       <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="http.message" href="#http.message">HTTP Message</a></h1>
    1194       <h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a>&nbsp;<a id="message.types" href="#message.types">Message Types</a></h2>
    1195       <p id="rfc.section.4.1.p.1">HTTP messages consist of requests from client to server and responses from server to client.</p>
    1196       <div id="rfc.figure.u.33"></div><pre class="inline"><span id="rfc.iref.g.69"></span>  <a href="#message.types" class="smpl">HTTP-message</a>   = <a href="#request" class="smpl">Request</a> / <a href="#response" class="smpl">Response</a>     ; HTTP/1.1 messages
    1197 </pre><p id="rfc.section.4.1.p.3">Request (<a href="#request" title="Request">Section&nbsp;5</a>) and Response (<a href="#response" title="Response">Section&nbsp;6</a>) messages use the generic message format of <a href="#RFC5322" id="rfc.xref.RFC5322.3"><cite title="Internet Message Format">[RFC5322]</cite></a> for transferring entities (the payload of the message). Both types of message consist of a start-line, zero or more header
    1198          fields (also known as "headers"), an empty line (i.e., a line with nothing preceding the CRLF) indicating the end of the header
    1199          fields, and possibly a message-body.
    1200       </p>
    1201       <div id="rfc.figure.u.34"></div><pre class="inline"><span id="rfc.iref.g.70"></span><span id="rfc.iref.g.71"></span>  <a href="#message.types" class="smpl">generic-message</a> = <a href="#message.types" class="smpl">start-line</a>
    1202                     *( <a href="#message.headers" class="smpl">message-header</a> <a href="#core.rules" class="smpl">CRLF</a> )
    1203                     <a href="#core.rules" class="smpl">CRLF</a>
    1204                     [ <a href="#message.body" class="smpl">message-body</a> ]
    1205   <a href="#message.types" class="smpl">start-line</a>      = <a href="#request-line" class="smpl">Request-Line</a> / <a href="#status-line" class="smpl">Status-Line</a>
    1206 </pre><p id="rfc.section.4.1.p.5">In the interest of robustness, servers <em class="bcp14">SHOULD</em> ignore any empty line(s) received where a Request-Line is expected. In other words, if the server is reading the protocol
    1207          stream at the beginning of a message and receives a CRLF first, it should ignore the CRLF.
    1208       </p>
    1209       <p id="rfc.section.4.1.p.6">Certain buggy HTTP/1.0 client implementations generate extra CRLF's after a POST request. To restate what is explicitly forbidden
    1210          by the BNF, an HTTP/1.1 client <em class="bcp14">MUST NOT</em> preface or follow a request with an extra CRLF.
    1211       </p>
    1212       <p id="rfc.section.4.1.p.7">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
    1213          implementation of HTTP into ignoring that field or processing the next line as a new request, either of which may result in
    1214          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.
    1215       </p>
    1216       <h2 id="rfc.section.4.2"><a href="#rfc.section.4.2">4.2</a>&nbsp;<a id="message.headers" href="#message.headers">Message Headers</a></h2>
    1217       <p id="rfc.section.4.2.p.1">HTTP header fields follow the same general format as Internet messages in <a href="http://tools.ietf.org/html/rfc5322#section-2.1">Section 2.1</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.4"><cite title="Internet Message Format">[RFC5322]</cite></a>. Each header field consists of a name followed by a colon (":"), optional whitespace, and the field value. Field names are
    1218          case-insensitive.
    1219       </p>
    1220       <div id="rfc.figure.u.35"></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>  <a href="#message.headers" class="smpl">message-header</a> = <a href="#message.headers" class="smpl">field-name</a> ":" OWS [ <a href="#message.headers" class="smpl">field-value</a> ] OWS
    1221   <a href="#message.headers" class="smpl">field-name</a>     = <a href="#rule.token.separators" class="smpl">token</a>
    1222   <a href="#message.headers" class="smpl">field-value</a>    = *( <a href="#message.headers" class="smpl">field-content</a> / <a href="#rule.whitespace" class="smpl">OWS</a> )
    1223   <a href="#message.headers" 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> )
    1224 </pre><p id="rfc.section.4.2.p.3">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 (allowing other character sets 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 charset <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> constrain their field-values to US-ASCII characters. Recipients <em class="bcp14">SHOULD</em> treat other (obs-text) octets in field-content as opaque data.
    1225       </p>
    1226       <p id="rfc.section.4.2.p.4">No whitespace is allowed between the header field-name and colon. For security reasons, any request message received containing
    1227          such whitespace <em class="bcp14">MUST</em> be rejected with a response code of 400 (Bad Request) and any such whitespace in a response message <em class="bcp14">MUST</em> be removed.
    1228       </p>
    1229       <p id="rfc.section.4.2.p.5">The field value <em class="bcp14">MAY</em> be preceded by optional whitespace; a single SP is preferred. The field-value does not include any leading or trailing white
    1230          space: OWS occurring before the first non-whitespace character of the field-value or after the last non-whitespace character
    1231          of the field-value is ignored and <em class="bcp14">MAY</em> be removed without changing the meaning of the header field.
    1232       </p>
    1233       <p id="rfc.section.4.2.p.6">Historically, HTTP header field values could be extended over multiple lines by preceding each extra line with at least one
    1234          space or horizontal tab character (line folding). This specification deprecates such line folding except within the message/http
    1235          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
    1236          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
    1237          forwarding the message downstream.
    1238       </p>
    1239       <div id="rule.comment">
    1240          <p id="rfc.section.4.2.p.7">    Comments can be included in some HTTP header fields by surrounding the comment text with parentheses. Comments are only allowed
    1241             in fields containing "comment" as part of their field value definition. In all other fields, parentheses are considered part
    1242             of the field value.
    1243          </p>
    1244       </div>
    1245       <div id="rfc.figure.u.36"></div><pre class="inline"><span id="rfc.iref.g.76"></span><span id="rfc.iref.g.77"></span>  <a href="#rule.comment" class="smpl">comment</a>        = "(" *( <a href="#rule.comment" class="smpl">ctext</a> / <a href="#rule.quoted-pair" class="smpl">quoted-pair</a> / <a href="#rule.comment" class="smpl">comment</a> ) ")"
    1246   <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>
    1247                  ; <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>
    1248 </pre><p id="rfc.section.4.2.p.9">The order in which header fields with differing field names are received is not significant. However, it is "good practice"
    1249          to send general-header fields first, followed by request-header or response-header fields, and ending with the entity-header
    1250          fields.
    1251       </p>
    1252       <p id="rfc.section.4.2.p.10">Multiple message-header fields with the same field-name <em class="bcp14">MAY</em> be present in a message if and only if the entire field-value for that header field is defined as a comma-separated list [i.e.,
    1253          #(values)]. It <em class="bcp14">MUST</em> be possible to combine the multiple header fields into one "field-name: field-value" pair, without changing the semantics
    1254          of the message, by appending each subsequent field-value to the first, each separated by a comma. The order in which header
    1255          fields with the same field-name are received is therefore significant to the interpretation of the combined field value, and
    1256          thus a proxy <em class="bcp14">MUST NOT</em> change the order of these field values when a message is forwarded.
    1257       </p>
    1258       <div class="note">
    1259          <p> <b>Note:</b> the "Set-Cookie" header as implemented in practice (as opposed to how it is specified in <a href="#RFC2109" id="rfc.xref.RFC2109.1"><cite title="HTTP State Management Mechanism">[RFC2109]</cite></a>) can occur multiple times, but does not use the list syntax, and thus cannot be combined into a single line. (See Appendix
    1260             A.2.3 of <a href="#Kri2001" id="rfc.xref.Kri2001.1"><cite title="HTTP Cookies: Standards, Privacy, and Politics">[Kri2001]</cite></a> for details.) Also note that the Set-Cookie2 header specified in <a href="#RFC2965" id="rfc.xref.RFC2965.1"><cite title="HTTP State Management Mechanism">[RFC2965]</cite></a> does not share this problem.
    1261          </p>
    1262       </div>
    1263       <h2 id="rfc.section.4.3"><a href="#rfc.section.4.3">4.3</a>&nbsp;<a id="message.body" href="#message.body">Message Body</a></h2>
    1264       <p id="rfc.section.4.3.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
    1265          message-body differs from the entity-body only when a transfer-coding has been applied, as indicated by the Transfer-Encoding
    1266          header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.2" title="Transfer-Encoding">Section&nbsp;8.7</a>).
    1267       </p>
    1268       <div id="rfc.figure.u.37"></div><pre class="inline"><span id="rfc.iref.g.78"></span>  <a href="#message.body" class="smpl">message-body</a> = <a href="#abnf.dependencies" class="smpl">entity-body</a>
    1269                / &lt;entity-body encoded as per <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding</a>&gt;
    1270 </pre><p id="rfc.section.4.3.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
    1271          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;3.3</a> places restrictions on when certain transfer-codings may be used.)
    1272       </p>
    1273       <p id="rfc.section.4.3.p.4">The rules for when a message-body is allowed in a message differ for requests and responses.</p>
    1274       <p id="rfc.section.4.3.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
    1275          in the request's message-headers. When a request message contains both a message-body of non-zero length and a method that
    1276          does 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
    1277          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.
    1278       </p>
    1279       <p id="rfc.section.4.3.p.6">For response messages, whether or not a message-body is included with a message is dependent on both the request method and
    1280          the response status code (<a href="#status.code.and.reason.phrase" title="Status Code and Reason Phrase">Section&nbsp;6.1.1</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),
    1281          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.
    1282       </p>
    1283       <h2 id="rfc.section.4.4"><a href="#rfc.section.4.4">4.4</a>&nbsp;<a id="message.length" href="#message.length">Message Length</a></h2>
    1284       <p id="rfc.section.4.4.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
    1285          have been applied. When a message-body is included with a message, the transfer-length of that body is determined by one of
    1286          the following (in order of precedence):
    1287       </p>
    1288       <p id="rfc.section.4.4.p.2"> </p>
    1289       <ol>
    1290          <li>
    1291             <p>Any response message which "<em class="bcp14">MUST NOT</em>" include a message-body (such as the 1xx, 204, and 304 responses and any response to a HEAD request) is always terminated
    1292                by the first empty line after the header fields, regardless of the entity-header fields present in the message.
    1293             </p>
    1294          </li>
    1295          <li>
    1296             <p>If a Transfer-Encoding header field (<a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.3" title="Transfer-Encoding">Section&nbsp;8.7</a>) is present and the "chunked" transfer-coding (<a href="#transfer.codings" title="Transfer Codings">Section&nbsp;3.3</a>) is used, the transfer-length is defined by the use of this transfer-coding. If a Transfer-Encoding header field is present
    1297                and the "chunked" transfer-coding is not present, the transfer-length is defined by the sender closing the connection.
    1298             </p>
    1299          </li>
    1300          <li>
    1301             <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
    1302                with both a Transfer-Encoding header field and a Content-Length header field, the latter <em class="bcp14">MUST</em> be ignored.
    1303             </p>
    1304          </li>
    1305          <li>
    1306             <p>If the message uses the media type "multipart/byteranges", and the transfer-length is not otherwise specified, then this self-delimiting
    1307                media type defines the transfer-length. This media type <em class="bcp14">MUST NOT</em> be used unless the sender knows that the recipient can parse it; the presence in a request of a Range header with multiple
    1308                byte-range specifiers from a 1.1 client implies that the client can parse multipart/byteranges responses.
    1309             </p>
    1310             <dl class="empty">
    1311                <dd>A range header might be forwarded by a 1.0 proxy that does not understand multipart/byteranges; in this case the server <em class="bcp14">MUST</em> delimit the message using methods defined in items 1, 3 or 5 of this section.
    1312                </dd>
    1313             </dl>
    1314          </li>
    1315          <li>
    1316             <p>By the server closing the connection. (Closing the connection cannot be used to indicate the end of a request body, since
    1317                that would leave no possibility for the server to send back a response.)
    1318             </p>
    1319          </li>
    1320       </ol>
    1321       <p id="rfc.section.4.4.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
    1322          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
    1323          to insist on receiving a valid Content-Length.
    1324       </p>
    1325       <p id="rfc.section.4.4.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;3.3</a>), thus allowing this mechanism to be used for messages when the message length cannot be determined in advance.
    1326       </p>
    1327       <p id="rfc.section.4.4.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.
    1328       </p>
    1329       <p id="rfc.section.4.4.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.
    1330       </p>
    1331       <h2 id="rfc.section.4.5"><a href="#rfc.section.4.5">4.5</a>&nbsp;<a id="general.header.fields" href="#general.header.fields">General Header Fields</a></h2>
    1332       <p id="rfc.section.4.5.p.1">There are a few header fields which have general applicability for both request and response messages, but which do not apply
    1333          to the entity being transferred. These header fields apply only to the message being transmitted.
    1334       </p>
    1335       <div id="rfc.figure.u.38"></div><pre class="inline"><span id="rfc.iref.g.79"></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>
    1336                  / <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>
    1337                  / <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>
    1338                  / <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>
    1339                  / <a href="#header.trailer" class="smpl">Trailer</a>                  ; <a href="#header.trailer" id="rfc.xref.header.trailer.2" title="Trailer">Section&nbsp;8.6</a>
    1340                  / <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding</a>        ; <a href="#header.transfer-encoding" id="rfc.xref.header.transfer-encoding.4" title="Transfer-Encoding">Section&nbsp;8.7</a>
    1341                  / <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>
    1342                  / <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>
    1343                  / <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>
    1344 </pre><p id="rfc.section.4.5.p.3">General-header field names can be extended reliably only in combination with a change in the protocol version. However, new
    1345          or experimental header fields may be given the semantics of general header fields if all parties in the communication recognize
    1346          them to be general-header fields. Unrecognized header fields are treated as entity-header fields.
    1347       </p>
    1348       <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="request" href="#request">Request</a></h1>
    1349       <p id="rfc.section.5.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
    1350          resource, the identifier of the resource, and the protocol version in use.
    1351       </p>
    1352       <div id="rfc.figure.u.39"></div><pre class="inline"><span id="rfc.iref.g.80"></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;5.1</a>
    1353                   *(( <a href="#general.header.fields" class="smpl">general-header</a>        ; <a href="#general.header.fields" title="General Header Fields">Section&nbsp;4.5</a>
    1354                    / <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>
    1355                    / <a href="#abnf.dependencies" class="smpl">entity-header</a> ) <a href="#core.rules" class="smpl">CRLF</a> )  ; <a href="#Part3" id="rfc.xref.Part3.8"><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>
    1356                   <a href="#core.rules" class="smpl">CRLF</a>
    1357                   [ <a href="#message.body" class="smpl">message-body</a> ]          ; <a href="#message.body" title="Message Body">Section&nbsp;4.3</a>
    1358 </pre><h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a>&nbsp;<a id="request-line" href="#request-line">Request-Line</a></h2>
    1359       <p id="rfc.section.5.1.p.1">The Request-Line begins with a method token, followed by the request-target and the protocol version, and ending with CRLF.
    1360          The elements are separated by SP characters. No CR or LF is allowed except in the final CRLF sequence.
    1361       </p>
    1362       <div id="rfc.figure.u.40"></div><pre class="inline"><span id="rfc.iref.g.81"></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>
    1363 </pre><h3 id="rfc.section.5.1.1"><a href="#rfc.section.5.1.1">5.1.1</a>&nbsp;<a id="method" href="#method">Method</a></h3>
    1364       <p id="rfc.section.5.1.1.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>
    1365       <div id="rfc.figure.u.41"></div><pre class="inline"><span id="rfc.iref.g.82"></span><span id="rfc.iref.g.83"></span>  <a href="#method" class="smpl">Method</a>         = <a href="#rule.token.separators" class="smpl">token</a>
    1366 </pre><h3 id="rfc.section.5.1.2"><a href="#rfc.section.5.1.2">5.1.2</a>&nbsp;<a id="request-target" href="#request-target">request-target</a></h3>
    1367       <p id="rfc.section.5.1.2.p.1">The request-target identifies the resource upon which to apply the request.</p>
    1368       <div id="rfc.figure.u.42"></div><pre class="inline"><span id="rfc.iref.g.84"></span>  <a href="#request-target" class="smpl">request-target</a> = "*"
    1369                  / <a href="#uri" class="smpl">absolute-URI</a>
    1370                  / ( <a href="#uri" class="smpl">path-absolute</a> [ "?" <a href="#uri" class="smpl">query</a> ] )
    1371                  / <a href="#uri" class="smpl">authority</a>
    1372 </pre><p id="rfc.section.5.1.2.p.3">The four options for request-target are dependent on the nature of the request. The asterisk "*" means that the request does
    1373          not apply to a particular resource, but to the server itself, and is only allowed when the method used does not necessarily
    1374          apply to a resource. One example would be
    1375       </p>
    1376       <div id="rfc.figure.u.43"></div><pre class="text">  OPTIONS * HTTP/1.1
    1377 </pre><p id="rfc.section.5.1.2.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,
    1378          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
    1379          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
    1380          Request-Line would be:
    1381       </p>
    1382       <div id="rfc.figure.u.44"></div><pre class="text">  GET http://www.example.org/pub/WWW/TheProject.html HTTP/1.1
    1383 </pre><p id="rfc.section.5.1.2.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.
    1384       </p>
    1385       <p id="rfc.section.5.1.2.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>).
    1386       </p>
    1387       <p id="rfc.section.5.1.2.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
    1388          absolute path of the URI <em class="bcp14">MUST</em> be transmitted (see <a href="#http.uri" title="http URI scheme">Section&nbsp;2.1.1</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
    1389          server would create a TCP connection to port 80 of the host "www.example.org" and send the lines:
    1390       </p>
    1391       <div id="rfc.figure.u.45"></div><pre class="text">  GET /pub/WWW/TheProject.html HTTP/1.1
    1392   Host: www.example.org
    1393 </pre><p id="rfc.section.5.1.2.p.11">followed by the remainder of the Request. Note that the absolute path cannot be empty; if none is present in the original
    1394          URI, it <em class="bcp14">MUST</em> be given as "/" (the server root).
    1395       </p>
    1396       <p id="rfc.section.5.1.2.p.12">If a proxy receives a request without any path in the request-target and the method specified is capable of supporting the
    1397          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.
    1398       </p>
    1399       <div id="rfc.figure.u.46"></div>
    1400       <p>For example, the request</p><pre class="text">  OPTIONS http://www.example.org:8001 HTTP/1.1
    1401 </pre><div id="rfc.figure.u.47"></div>
    1402       <p>would be forwarded by the proxy as</p><pre class="text">  OPTIONS * HTTP/1.1
    1403   Host: www.example.org:8001
    1404 </pre>  <p>after connecting to port 8001 of host "www.example.org".</p>
    1405       <p id="rfc.section.5.1.2.p.15">The request-target is transmitted in the format specified in <a href="#http.uri" title="http URI scheme">Section&nbsp;2.1.1</a>. If the request-target is percent-encoded (<a href="#RFC3986" id="rfc.xref.RFC3986.19"><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.
    1406       </p>
    1407       <p id="rfc.section.5.1.2.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
    1408          above to replace a null path-absolute with "/".
    1409       </p>
    1410       <div class="note">
    1411          <p> <b>Note:</b> The "no rewrite" rule prevents the proxy from changing the meaning of the request when the origin server is improperly using
    1412             a non-reserved URI character for a reserved purpose. Implementors should be aware that some pre-HTTP/1.1 proxies have been
    1413             known to rewrite the request-target.
    1414          </p>
    1415       </div>
    1416       <p id="rfc.section.5.1.2.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
    1417          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>).
    1418       </p>
    1419       <p id="rfc.section.5.1.2.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.
    1420       </p>
    1421       <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</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>
    1422       <p id="rfc.section.5.2.p.1">The exact resource identified by an Internet request is determined by examining both the request-target and the Host header
    1423          field.
    1424       </p>
    1425       <p id="rfc.section.5.2.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.)
    1426       </p>
    1427       <p id="rfc.section.5.2.p.3">An origin server that does differentiate resources based on the host requested (sometimes referred to as virtual hosts or
    1428          vanity host names) <em class="bcp14">MUST</em> use the following rules for determining the requested resource on an HTTP/1.1 request:
    1429       </p>
    1430       <ol>
    1431          <li>If request-target is an absolute-URI, the host is part of the request-target. Any Host header field value in the request <em class="bcp14">MUST</em> be ignored.
    1432          </li>
    1433          <li>If the request-target is not an absolute-URI, and the request includes a Host header field, the host is determined by the
    1434             Host header field value.
    1435          </li>
    1436          <li>If the host as determined by rule 1 or 2 is not a valid host on the server, the response <em class="bcp14">MUST</em> be a 400 (Bad Request) error message.
    1437          </li>
    1438       </ol>
    1439       <p id="rfc.section.5.2.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
    1440          what exact resource is being requested.
    1441       </p>
    1442       <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a id="response" href="#response">Response</a></h1>
    1443       <p id="rfc.section.6.p.1">After receiving and interpreting a request message, a server responds with an HTTP response message.</p>
    1444       <div id="rfc.figure.u.48"></div><pre class="inline"><span id="rfc.iref.g.85"></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;6.1</a>
    1445                   *(( <a href="#general.header.fields" class="smpl">general-header</a>        ; <a href="#general.header.fields" title="General Header Fields">Section&nbsp;4.5</a>
    1446                    / <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>
    1447                    / <a href="#abnf.dependencies" class="smpl">entity-header</a> ) <a href="#core.rules" class="smpl">CRLF</a> )  ; <a href="#Part3" id="rfc.xref.Part3.9"><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>
    1448                   <a href="#core.rules" class="smpl">CRLF</a>
    1449                   [ <a href="#message.body" class="smpl">message-body</a> ]          ; <a href="#message.body" title="Message Body">Section&nbsp;4.3</a>
    1450 </pre><h2 id="rfc.section.6.1"><a href="#rfc.section.6.1">6.1</a>&nbsp;<a id="status-line" href="#status-line">Status-Line</a></h2>
    1451       <p id="rfc.section.6.1.p.1">The first line of a Response message is the Status-Line, consisting of the protocol version followed by a numeric status code
    1452          and its associated textual phrase, with each element separated by SP characters. No CR or LF is allowed except in the final
    1453          CRLF sequence.
    1454       </p>
    1455       <div id="rfc.figure.u.49"></div><pre class="inline"><span id="rfc.iref.g.86"></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>
    1456 </pre><h3 id="rfc.section.6.1.1"><a href="#rfc.section.6.1.1">6.1.1</a>&nbsp;<a id="status.code.and.reason.phrase" href="#status.code.and.reason.phrase">Status Code and Reason Phrase</a></h3>
    1457       <p id="rfc.section.6.1.1.p.1">The Status-Code element is a 3-digit integer result code of the attempt to understand and satisfy the request. These codes
    1458          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,
    1459          out of deference to earlier Internet application protocols that were more frequently used with interactive text clients. A
    1460          client <em class="bcp14">SHOULD</em> ignore the content of the Reason Phrase.
    1461       </p>
    1462       <p id="rfc.section.6.1.1.p.2">The first digit of the Status-Code defines the class of response. The last two digits do not have any categorization role.
    1463          There are 5 values for the first digit:
    1464       </p>
    1465       <ul>
    1466          <li>1xx: Informational - Request received, continuing process</li>
    1467          <li>2xx: Success - The action was successfully received, understood, and accepted</li>
    1468          <li>3xx: Redirection - Further action must be taken in order to complete the request</li>
    1469          <li>4xx: Client Error - The request contains bad syntax or cannot be fulfilled</li>
    1470          <li>5xx: Server Error - The server failed to fulfill an apparently valid request</li>
    1471       </ul>
    1472       <div id="rfc.figure.u.50"></div><pre class="inline"><span id="rfc.iref.g.87"></span><span id="rfc.iref.g.88"></span><span id="rfc.iref.g.89"></span>  <a href="#status.code.and.reason.phrase" class="smpl">Status-Code</a>    = 3<a href="#core.rules" class="smpl">DIGIT</a>
    1473   <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> )
    1474 </pre><h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a id="connections" href="#connections">Connections</a></h1>
     1474      <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a id="connections" href="#connections">Connections</a></h1>
    14751475      <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>
    14761476      <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>
    … …  
    15191519      <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.
    15201520      </p>
    1521       <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;4.4</a>.
     1521      <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>.
    15221522      </p>
    15231523      <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>
    … …  
    15661566      <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>
    15671567      <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,
    1568          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;3.3</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.
     1568         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.
    15691569      </p>
    15701570      <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>
    … …  
    16951695</pre><p id="rfc.section.8.2.p.3">An example is</p>
    16961696      <div id="rfc.figure.u.54"></div><pre class="text">  Content-Length: 3495
    1697 </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;4.4</a>.
    1698       </p>
    1699       <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;4.4</a> describes how to determine the length of a message-body if a Content-Length is not given.
     1697</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>.
     1698      </p>
     1699      <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.
    17001700      </p>
    17011701      <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
    17021702         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
    1703          in <a href="#message.length" title="Message Length">Section&nbsp;4.4</a>.
     1703         in <a href="#message.length" title="Message Length">Section&nbsp;3.4</a>.
    17041704      </p>
    17051705      <div id="rfc.iref.d.1"></div>
    … …  
    17071707      <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>
    17081708      <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
    1709          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.RFC5322.5"><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;3.2</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.
     1709         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.RFC5322.5"><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.
    17101710      </p>
    17111711      <div id="rfc.figure.u.55"></div><pre class="inline"><span id="rfc.iref.g.95"></span><span id="rfc.iref.g.96"></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>
    … …  
    17441744      <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>
    17451745      <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
    1746          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;2.1.1</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
     1746         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;2.3.1</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
    17471747         gateway to differentiate between internally-ambiguous URLs, such as the root "/" URL of a server for multiple host names on
    17481748         a single IP address.
    17491749      </p>
    17501750      <div id="rfc.figure.u.57"></div><pre class="inline"><span id="rfc.iref.g.97"></span><span id="rfc.iref.g.98"></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>
    1751   <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;2.1.1</a>
     1751  <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;2.3.1</a>
    17521752</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
    17531753         URL). For example, a request on the origin server for &lt;http://www.example.org/pub/WWW/&gt; would properly include:
    … …  
    17591759         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.
    17601760      </p>
    1761       <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">5.2</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.
     1761      <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.
    17621762      </p>
    17631763      <div id="rfc.iref.t.1"></div>
    … …  
    17661766      <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
    17671767         or not it is willing to accept trailer fields in a chunked transfer-coding. Its value may consist of the keyword "trailers"
    1768          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;3.3</a>).
     1768         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>).
    17691769      </p>
    17701770      <div id="rfc.figure.u.59"></div><pre class="inline"><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><span id="rfc.iref.g.103"></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>
    … …  
    17741774  <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> ) ]
    17751775</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,
    1776          as defined in <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">Section&nbsp;3.3.1</a>. This keyword is reserved for use with transfer-coding values even though it does not itself represent a transfer-coding.
     1776         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.
    17771777      </p>
    17781778      <p id="rfc.section.8.5.p.4">Examples of its use are:</p>
    … …  
    17961796         <li>
    17971797            <p>If the transfer-coding being tested is one of the transfer-codings listed in the TE field, then it is acceptable unless it
    1798                is accompanied by a qvalue of 0. (As defined in <a href="#quality.values" title="Quality Values">Section&nbsp;3.5</a>, a qvalue of 0 means "not acceptable.")
     1798               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.")
    17991799            </p>
    18001800         </li>
    … …  
    18191819         to know which header fields to expect in the trailer.
    18201820      </p>
    1821       <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;3.3.1</a> for restrictions on the use of trailer fields in a "chunked" transfer-coding.
     1821      <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.
    18221822      </p>
    18231823      <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:
    … …  
    18381838                        <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding-v</a>
    18391839  <a href="#header.transfer-encoding" class="smpl">Transfer-Encoding-v</a> = 1#<a href="#transfer.codings" class="smpl">transfer-coding</a>
    1840 </pre><p id="rfc.section.8.7.p.3">Transfer-codings are defined in <a href="#transfer.codings" title="Transfer Codings">Section&nbsp;3.3</a>. An example is:
     1840</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:
    18411841      </p>
    18421842      <div id="rfc.figure.u.63"></div><pre class="text">  Transfer-Encoding: chunked
    … …  
    18721872      </p>
    18731873      <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
    1874          by the HTTP version rules of <a href="#http.version" title="HTTP Version">Section&nbsp;3.1</a> and future updates to this specification. Any token can be used as a protocol name; however, it will only be useful if both
     1874         by the HTTP version rules of <a href="#http.version" title="HTTP Version">Section&nbsp;2.2</a> and future updates to this specification. Any token can be used as a protocol name; however, it will only be useful if both
    18751875         the client and server associate the name with the same protocol.
    18761876      </p>
    … …  
    20032003      <p id="rfc.section.9.1.p.2">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
    20042004      <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>
    2005       <p id="rfc.section.9.2.p.1">The entry for the "http" URI Scheme 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 <a href="#http.uri" title="http URI scheme">Section&nbsp;2.1.1</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>).
     2005      <p id="rfc.section.9.2.p.1">The entry for the "http" URI Scheme 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 <a href="#http.uri" title="http URI scheme">Section&nbsp;2.3.1</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>).
    20062006      </p>
    20072007      <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>
    … …  
    24502450      <p id="rfc.section.B.1.p.1">This section summarizes major differences between versions HTTP/1.0 and HTTP/1.1.</p>
    24512451      <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>
    2452       <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;5.1.2</a>) are among the most important changes defined by this specification.
     2452      <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.
    24532453      </p>
    24542454      <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
    … …  
    24932493      <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
    24942494         for transfer encoding that may not be self delimiting); it was important to straighten out exactly how message lengths are
    2495          computed. (Sections <a href="#transfer.codings" title="Transfer Codings">3.3</a>, <a href="#message.length" title="Message Length">4.4</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>)
     2495         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>)
    24962496      </p>
    24972497      <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
    2498          implementations (<a href="#http.version" title="HTTP Version">Section&nbsp;3.1</a>)
    2499       </p>
    2500       <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;3.5</a>)
     2498         implementations (<a href="#http.version" title="HTTP Version">Section&nbsp;2.2</a>)
     2499      </p>
     2500      <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>)
    25012501      </p>
    25022502      <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
    … …  
    25042504         codings), a new header field (TE) and enabling trailer headers in the future. Transfer encoding is a major performance benefit,
    25052505         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
    2506          authentication trailers, chunked encoding and HTTP/1.0 clients.(Section <a href="#transfer.codings" title="Transfer Codings">3.3</a>, <a href="#chunked.transfer.encoding" title="Chunked Transfer Coding">3.3.1</a>, and <a href="#header.te" id="rfc.xref.header.te.5" title="TE">8.5</a>)
     2506         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>)
    25072507      </p>
    25082508      <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>
    … …  
    25142514         (the TEXT rule was removed) (<a href="#basic.rules" title="Basic Rules">Section&nbsp;1.2.2</a>)
    25152515      </p>
    2516       <p id="rfc.section.B.4.p.3">Clarify that HTTP-Version is case sensitive. (<a href="#http.version" title="HTTP Version">Section&nbsp;3.1</a>)
    2517       </p>
    2518       <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">3.3</a> and <a href="#message.length" title="Message Length">4.4</a>)
    2519       </p>
    2520       <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;3.3.1</a>)
    2521       </p>
    2522       <p id="rfc.section.B.4.p.6">Require that invalid whitespace around field-names be rejected. (<a href="#message.headers" title="Message Headers">Section&nbsp;4.2</a>)
    2523       </p>
    2524       <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;5.1.2</a>)
     2516      <p id="rfc.section.B.4.p.3">Clarify that HTTP-Version is case sensitive. (<a href="#http.version" title="HTTP Version">Section&nbsp;2.2</a>)
     2517      </p>
     2518      <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>)
     2519      </p>
     2520      <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>)
     2521      </p>
     2522      <p id="rfc.section.B.4.p.6">Require that invalid whitespace around field-names be rejected. (<a href="#message.headers" title="Message Headers">Section&nbsp;3.2</a>)
     2523      </p>
     2524      <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>)
    25252525      </p>
    25262526      <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>)
    … …  
    25842584      </p>
    25852585      <dl class="empty">
    2586          <dd>The basic unit of HTTP communication, consisting of a structured sequence of octets matching the syntax defined in <a href="#http.message" title="HTTP Message">Section&nbsp;4</a> and transmitted via the connection.
     2586         <dd>The basic unit of HTTP communication, consisting of a structured sequence of octets matching the syntax defined in <a href="#http.message" title="HTTP Message">Section&nbsp;3</a> and transmitted via the connection.
    25872587         </dd>
    25882588      </dl>
    … …  
    26062606      </p>
    26072607      <dl class="empty">
    2608          <dd>An HTTP request message, as defined in <a href="#request" title="Request">Section&nbsp;5</a>.
     2608         <dd>An HTTP request message, as defined in <a href="#request" title="Request">Section&nbsp;4</a>.
    26092609         </dd>
    26102610      </dl>
    … …  
    26122612      </p>
    26132613      <dl class="empty">
    2614          <dd>An HTTP response message, as defined in <a href="#response" title="Response">Section&nbsp;6</a>.
     2614         <dd>An HTTP response message, as defined in <a href="#response" title="Response">Section&nbsp;5</a>.
    26152615         </dd>
    26162616      </dl>
    … …  
    30633063                  <li class="indline1">client&nbsp;&nbsp;<a class="iref" href="#rfc.iref.c.5">C</a></li>
    30643064                  <li class="indline1">connection&nbsp;&nbsp;<a class="iref" href="#rfc.iref.c.6">C</a></li>
    3065                   <li class="indline1">Connection header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.connection.1">4.5</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.1"><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>
     3065                  <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.1"><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>
    30663066                  <li class="indline1">content negotiation&nbsp;&nbsp;<a class="iref" href="#rfc.iref.c.7">C</a></li>
    3067                   <li class="indline1">Content-Length header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.content-length.1">4.4</a>, <a class="iref" href="#rfc.iref.c.2"><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>
     3067                  <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.2"><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>
    30683068               </ul>
    30693069            </li>
    30703070            <li class="indline0"><a id="rfc.index.D" href="#rfc.index.D"><b>D</b></a><ul class="ind">
    3071                   <li class="indline1">Date header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.date.1">4.5</a>, <a class="iref" href="#rfc.iref.d.1"><b>8.3</b></a>, <a class="iref" href="#rfc.xref.header.date.2">9.1</a></li>
     3071                  <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.1"><b>8.3</b></a>, <a class="iref" href="#rfc.xref.header.date.2">9.1</a></li>
    30723072                  <li class="indline1">downstream&nbsp;&nbsp;<a class="iref" href="#rfc.iref.d.2">C</a></li>
    30733073               </ul>
    … …  
    30813081                  <li class="indline1"><tt>Grammar</tt>&nbsp;&nbsp;
    30823082                     <ul class="ind">
    3083                         <li class="indline1"><tt>absolute-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.24"><b>2.1</b></a></li>
     3083                        <li class="indline1"><tt>absolute-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.26"><b>2.3</b></a></li>
    30843084                        <li class="indline1">ALPHA&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.1"><b>1.2</b></a></li>
    3085                         <li class="indline1"><tt>asctime-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.49"><b>3.2</b></a></li>
    3086                         <li class="indline1"><tt>attribute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.53"><b>3.3</b></a></li>
    3087                         <li class="indline1"><tt>authority</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.25"><b>2.1</b></a></li>
     3085                        <li class="indline1"><tt>asctime-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.70"><b>6.1</b></a></li>
     3086                        <li class="indline1"><tt>attribute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.74"><b>6.2</b></a></li>
     3087                        <li class="indline1"><tt>authority</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.27"><b>2.3</b></a></li>
    30883088                        <li class="indline1"><tt>BWS</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.15"><b>1.2.2</b></a></li>
    3089                         <li class="indline1"><tt>chunk</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.58"><b>3.3.1</b></a></li>
    3090                         <li class="indline1"><tt>chunk-data</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.64"><b>3.3.1</b></a></li>
    3091                         <li class="indline1"><tt>chunk-ext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.61"><b>3.3.1</b></a></li>
    3092                         <li class="indline1"><tt>chunk-ext-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.62"><b>3.3.1</b></a></li>
    3093                         <li class="indline1"><tt>chunk-ext-val</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.63"><b>3.3.1</b></a></li>
    3094                         <li class="indline1"><tt>chunk-size</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.59"><b>3.3.1</b></a></li>
    3095                         <li class="indline1"><tt>Chunked-Body</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.57"><b>3.3.1</b></a></li>
    3096                         <li class="indline1"><tt>comment</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.76"><b>4.2</b></a></li>
     3089                        <li class="indline1"><tt>chunk</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.79"><b>6.2.1</b></a></li>
     3090                        <li class="indline1"><tt>chunk-data</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.85"><b>6.2.1</b></a></li>
     3091                        <li class="indline1"><tt>chunk-ext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.82"><b>6.2.1</b></a></li>
     3092                        <li class="indline1"><tt>chunk-ext-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.83"><b>6.2.1</b></a></li>
     3093                        <li class="indline1"><tt>chunk-ext-val</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.84"><b>6.2.1</b></a></li>
     3094                        <li class="indline1"><tt>chunk-size</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.80"><b>6.2.1</b></a></li>
     3095                        <li class="indline1"><tt>Chunked-Body</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.78"><b>6.2.1</b></a></li>
     3096                        <li class="indline1"><tt>comment</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.41"><b>3.2</b></a></li>
    30973097                        <li class="indline1"><tt>Connection</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.90"><b>8.1</b></a></li>
    30983098                        <li class="indline1"><tt>connection-token</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.92"><b>8.1</b></a></li>
    … …  
    31023102                        <li class="indline1">CR&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.2"><b>1.2</b></a></li>
    31033103                        <li class="indline1">CRLF&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.3"><b>1.2</b></a></li>
    3104                         <li class="indline1"><tt>ctext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.77"><b>4.2</b></a></li>
     3104                        <li class="indline1"><tt>ctext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.42"><b>3.2</b></a></li>
    31053105                        <li class="indline1">CTL&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.4"><b>1.2</b></a></li>
    31063106                        <li class="indline1"><tt>Date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.95"><b>8.3</b></a></li>
    31073107                        <li class="indline1"><tt>Date-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.96"><b>8.3</b></a></li>
    3108                         <li class="indline1"><tt>date1</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.36"><b>3.2</b></a></li>
    3109                         <li class="indline1"><tt>date2</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.55"><b>3.3</b></a></li>
    3110                         <li class="indline1"><tt>date3</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.56"><b>3.3</b></a></li>
    3111                         <li class="indline1"><tt>day</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.43"><b>3.2</b></a></li>
    3112                         <li class="indline1"><tt>day-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.41"><b>3.2</b></a></li>
    3113                         <li class="indline1"><tt>day-name-l</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.42"><b>3.2</b></a></li>
     3108                        <li class="indline1"><tt>date1</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.57"><b>6.1</b></a></li>
     3109                        <li class="indline1"><tt>date2</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.76"><b>6.2</b></a></li>
     3110                        <li class="indline1"><tt>date3</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.77"><b>6.2</b></a></li>
     3111                        <li class="indline1"><tt>day</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.64"><b>6.1</b></a></li>
     3112                        <li class="indline1"><tt>day-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.62"><b>6.1</b></a></li>
     3113                        <li class="indline1"><tt>day-name-l</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.63"><b>6.1</b></a></li>
    31143114                        <li class="indline1">DIGIT&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.5"><b>1.2</b></a></li>
    31153115                        <li class="indline1">DQUOTE&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.6"><b>1.2</b></a></li>
    3116                         <li class="indline1"><tt>extension-code</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.88"><b>6.1.1</b></a></li>
    3117                         <li class="indline1"><tt>extension-method</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.83"><b>5.1.1</b></a></li>
    3118                         <li class="indline1"><tt>field-content</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.75"><b>4.2</b></a></li>
    3119                         <li class="indline1"><tt>field-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.73"><b>4.2</b></a></li>
    3120                         <li class="indline1"><tt>field-value</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.74"><b>4.2</b></a></li>
    3121                         <li class="indline1"><tt>general-header</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.79"><b>4.5</b></a></li>
    3122                         <li class="indline1"><tt>generic-message</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.70"><b>4.1</b></a></li>
    3123                         <li class="indline1"><tt>GMT</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.46"><b>3.2</b></a></li>
     3116                        <li class="indline1"><tt>extension-code</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.53"><b>5.1.1</b></a></li>
     3117                        <li class="indline1"><tt>extension-method</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.48"><b>4.1.1</b></a></li>
     3118                        <li class="indline1"><tt>field-content</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.40"><b>3.2</b></a></li>
     3119                        <li class="indline1"><tt>field-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.38"><b>3.2</b></a></li>
     3120                        <li class="indline1"><tt>field-value</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.39"><b>3.2</b></a></li>
     3121                        <li class="indline1"><tt>general-header</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.44"><b>3.5</b></a></li>
     3122                        <li class="indline1"><tt>generic-message</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.35"><b>3.1</b></a></li>
     3123                        <li class="indline1"><tt>GMT</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.67"><b>6.1</b></a></li>
    31243124                        <li class="indline1">HEXDIG&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.7"><b>1.2</b></a></li>
    31253125                        <li class="indline1"><tt>Host</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.97"><b>8.4</b></a></li>
    31263126                        <li class="indline1"><tt>Host-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.98"><b>8.4</b></a></li>
    3127                         <li class="indline1"><tt>hour</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.38"><b>3.2</b></a></li>
    3128                         <li class="indline1"><tt>HTTP-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.34"><b>3.2</b></a></li>
    3129                         <li class="indline1"><tt>HTTP-message</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.69"><b>4.1</b></a></li>
    3130                         <li class="indline1"><tt>HTTP-Prot-Name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.33"><b>3.1</b></a></li>
    3131                         <li class="indline1"><tt>http-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.30"><b>2.1.1</b></a></li>
    3132                         <li class="indline1"><tt>HTTP-Version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.32"><b>3.1</b></a></li>
    3133                         <li class="indline1"><tt>https-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.31"><b>2.1.2</b></a></li>
    3134                         <li class="indline1"><tt>last-chunk</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.60"><b>3.3.1</b></a></li>
     3127                        <li class="indline1"><tt>hour</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.59"><b>6.1</b></a></li>
     3128                        <li class="indline1"><tt>HTTP-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.55"><b>6.1</b></a></li>
     3129                        <li class="indline1"><tt>HTTP-message</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.34"><b>3.1</b></a></li>
     3130                        <li class="indline1"><tt>HTTP-Prot-Name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.24"><b>2.2</b></a></li>
     3131                        <li class="indline1"><tt>http-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.32"><b>2.3.1</b></a></li>
     3132                        <li class="indline1"><tt>HTTP-Version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.23"><b>2.2</b></a></li>
     3133                        <li class="indline1"><tt>https-URI</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.33"><b>2.3.2</b></a></li>
     3134                        <li class="indline1"><tt>last-chunk</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.81"><b>6.2.1</b></a></li>
    31353135                        <li class="indline1">LF&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.8"><b>1.2</b></a></li>
    3136                         <li class="indline1"><tt>message-body</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.78"><b>4.3</b></a></li>
    3137                         <li class="indline1"><tt>message-header</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.72"><b>4.2</b></a></li>
    3138                         <li class="indline1"><tt>Method</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.82"><b>5.1.1</b></a></li>
    3139                         <li class="indline1"><tt>minute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.39"><b>3.2</b></a></li>
    3140                         <li class="indline1"><tt>month</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.44"><b>3.2</b></a></li>
    3141                         <li class="indline1"><tt>obs-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.47"><b>3.2</b></a></li>
     3136                        <li class="indline1"><tt>message-body</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.43"><b>3.3</b></a></li>
     3137                        <li class="indline1"><tt>message-header</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.37"><b>3.2</b></a></li>
     3138                        <li class="indline1"><tt>Method</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.47"><b>4.1.1</b></a></li>
     3139                        <li class="indline1"><tt>minute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.60"><b>6.1</b></a></li>
     3140                        <li class="indline1"><tt>month</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.65"><b>6.1</b></a></li>
     3141                        <li class="indline1"><tt>obs-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.68"><b>6.1</b></a></li>
    31423142                        <li class="indline1"><tt>obs-text</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.20"><b>1.2.2</b></a></li>
    31433143                        <li class="indline1">OCTET&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.9"><b>1.2</b></a></li>
    31443144                        <li class="indline1"><tt>OWS</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.13"><b>1.2.2</b></a></li>
    3145                         <li class="indline1"><tt>path-absolute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.26"><b>2.1</b></a></li>
    3146                         <li class="indline1"><tt>port</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.27"><b>2.1</b></a></li>
    3147                         <li class="indline1"><tt>product</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.66"><b>3.4</b></a></li>
    3148                         <li class="indline1"><tt>product-version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.67"><b>3.4</b></a></li>
     3145                        <li class="indline1"><tt>path-absolute</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.28"><b>2.3</b></a></li>
     3146                        <li class="indline1"><tt>port</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.29"><b>2.3</b></a></li>
     3147                        <li class="indline1"><tt>product</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.87"><b>6.3</b></a></li>
     3148                        <li class="indline1"><tt>product-version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.88"><b>6.3</b></a></li>
    31493149                        <li class="indline1"><tt>protocol-name</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.113"><b>8.9</b></a></li>
    31503150                        <li class="indline1"><tt>protocol-version</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.114"><b>8.9</b></a></li>
    31513151                        <li class="indline1"><tt>pseudonym</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.116"><b>8.9</b></a></li>
    31523152                        <li class="indline1"><tt>qdtext</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.19"><b>1.2.2</b></a></li>
    3153                         <li class="indline1"><tt>query</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.28"><b>2.1</b></a></li>
     3153                        <li class="indline1"><tt>query</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.30"><b>2.3</b></a></li>
    31543154                        <li class="indline1"><tt>quoted-pair</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.22"><b>1.2.2</b></a></li>
    31553155                        <li class="indline1"><tt>quoted-string</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.18"><b>1.2.2</b></a></li>
    31563156                        <li class="indline1"><tt>quoted-text</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.21"><b>1.2.2</b></a></li>
    3157                         <li class="indline1"><tt>qvalue</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.68"><b>3.5</b></a></li>
    3158                         <li class="indline1"><tt>Reason-Phrase</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.89"><b>6.1.1</b></a></li>
     3157                        <li class="indline1"><tt>qvalue</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.89"><b>6.4</b></a></li>
     3158                        <li class="indline1"><tt>Reason-Phrase</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.54"><b>5.1.1</b></a></li>
    31593159                        <li class="indline1"><tt>received-by</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.115"><b>8.9</b></a></li>
    31603160                        <li class="indline1"><tt>received-protocol</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.112"><b>8.9</b></a></li>
    3161                         <li class="indline1"><tt>Request</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.80"><b>5</b></a></li>
    3162                         <li class="indline1"><tt>Request-Line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.81"><b>5.1</b></a></li>
    3163                         <li class="indline1"><tt>request-target</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.84"><b>5.1.2</b></a></li>
    3164                         <li class="indline1"><tt>Response</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.85"><b>6</b></a></li>
    3165                         <li class="indline1"><tt>rfc1123-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.35"><b>3.2</b></a></li>
    3166                         <li class="indline1"><tt>rfc850-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.48"><b>3.2</b></a></li>
     3161                        <li class="indline1"><tt>Request</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.45"><b>4</b></a></li>
     3162                        <li class="indline1"><tt>Request-Line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.46"><b>4.1</b></a></li>
     3163                        <li class="indline1"><tt>request-target</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.49"><b>4.1.2</b></a></li>
     3164                        <li class="indline1"><tt>Response</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.50"><b>5</b></a></li>
     3165                        <li class="indline1"><tt>rfc1123-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.56"><b>6.1</b></a></li>
     3166                        <li class="indline1"><tt>rfc850-date</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.69"><b>6.1</b></a></li>
    31673167                        <li class="indline1"><tt>RWS</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.14"><b>1.2.2</b></a></li>
    3168                         <li class="indline1"><tt>second</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.40"><b>3.2</b></a></li>
     3168                        <li class="indline1"><tt>second</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.61"><b>6.1</b></a></li>
    31693169                        <li class="indline1">SP&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.10"><b>1.2</b></a></li>
    3170                         <li class="indline1"><tt>start-line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.71"><b>4.1</b></a></li>
    3171                         <li class="indline1"><tt>Status-Code</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.87"><b>6.1.1</b></a></li>
    3172                         <li class="indline1"><tt>Status-Line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.86"><b>6.1</b></a></li>
     3170                        <li class="indline1"><tt>start-line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.36"><b>3.1</b></a></li>
     3171                        <li class="indline1"><tt>Status-Code</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.52"><b>5.1.1</b></a></li>
     3172                        <li class="indline1"><tt>Status-Line</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.51"><b>5.1</b></a></li>
    31733173                        <li class="indline1"><tt>t-codings</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.101"><b>8.5</b></a></li>
    31743174                        <li class="indline1"><tt>tchar</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.17"><b>1.2.2</b></a></li>
    … …  
    31773177                        <li class="indline1"><tt>te-params</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.102"><b>8.5</b></a></li>
    31783178                        <li class="indline1"><tt>TE-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.100"><b>8.5</b></a></li>
    3179                         <li class="indline1"><tt>time-of-day</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.37"><b>3.2</b></a></li>
     3179                        <li class="indline1"><tt>time-of-day</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.58"><b>6.1</b></a></li>
    31803180                        <li class="indline1"><tt>token</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.16"><b>1.2.2</b></a></li>
    31813181                        <li class="indline1"><tt>Trailer</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.104"><b>8.6</b></a></li>
    3182                         <li class="indline1"><tt>trailer-part</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.65"><b>3.3.1</b></a></li>
     3182                        <li class="indline1"><tt>trailer-part</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.86"><b>6.2.1</b></a></li>
    31833183                        <li class="indline1"><tt>Trailer-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.105"><b>8.6</b></a></li>
    3184                         <li class="indline1"><tt>transfer-coding</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.50"><b>3.3</b></a></li>
     3184                        <li class="indline1"><tt>transfer-coding</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.71"><b>6.2</b></a></li>
    31853185                        <li class="indline1"><tt>Transfer-Encoding</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.106"><b>8.7</b></a></li>
    31863186                        <li class="indline1"><tt>Transfer-Encoding-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.107"><b>8.7</b></a></li>
    3187                         <li class="indline1"><tt>transfer-extension</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.51"><b>3.3</b></a></li>
    3188                         <li class="indline1"><tt>transfer-parameter</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.52"><b>3.3</b></a></li>
     3187                        <li class="indline1"><tt>transfer-extension</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.72"><b>6.2</b></a></li>
     3188                        <li class="indline1"><tt>transfer-parameter</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.73"><b>6.2</b></a></li>
    31893189                        <li class="indline1"><tt>Upgrade</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.108"><b>8.8</b></a></li>
    31903190                        <li class="indline1"><tt>Upgrade-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.109"><b>8.8</b></a></li>
    3191                         <li class="indline1"><tt>uri-host</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.29"><b>2.1</b></a></li>
    3192                         <li class="indline1"><tt>URI-reference</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.23"><b>2.1</b></a></li>
    3193                         <li class="indline1"><tt>value</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.54"><b>3.3</b></a></li>
     3191                        <li class="indline1"><tt>uri-host</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.31"><b>2.3</b></a></li>
     3192                        <li class="indline1"><tt>URI-reference</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.25"><b>2.3</b></a></li>
     3193                        <li class="indline1"><tt>value</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.75"><b>6.2</b></a></li>
    31943194                        <li class="indline1">VCHAR&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.11"><b>1.2</b></a></li>
    31953195                        <li class="indline1"><tt>Via</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.110"><b>8.9</b></a></li>
    31963196                        <li class="indline1"><tt>Via-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.111"><b>8.9</b></a></li>
    31973197                        <li class="indline1">WSP&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.12"><b>1.2</b></a></li>
    3198                         <li class="indline1"><tt>year</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.45"><b>3.2</b></a></li>
     3198                        <li class="indline1"><tt>year</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.66"><b>6.1</b></a></li>
    31993199                     </ul>
    32003200                  </li>
    … …  
    32043204                  <li class="indline1">Headers&nbsp;&nbsp;
    32053205                     <ul class="ind">
    3206                         <li class="indline1">Connection&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.connection.1">4.5</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.3"><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>
    3207                         <li class="indline1">Content-Length&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.content-length.1">4.4</a>, <a class="iref" href="#rfc.iref.h.4"><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>
    3208                         <li class="indline1">Date&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.date.1">4.5</a>, <a class="iref" href="#rfc.iref.h.5"><b>8.3</b></a>, <a class="iref" href="#rfc.xref.header.date.2">9.1</a></li>
     3206                        <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.3"><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>
     3207                        <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.4"><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>
     3208                        <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.5"><b>8.3</b></a>, <a class="iref" href="#rfc.xref.header.date.2">9.1</a></li>
    32093209                        <li class="indline1">Host&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.7"><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>
    3210                         <li class="indline1">TE&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.te.1">3.3</a>, <a class="iref" href="#rfc.xref.header.te.2">3.3.1</a>, <a class="iref" href="#rfc.xref.header.te.3">3.5</a>, <a class="iref" href="#rfc.iref.h.8"><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>
    3211                         <li class="indline1">Trailer&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.trailer.1">3.3.1</a>, <a class="iref" href="#rfc.xref.header.trailer.2">4.5</a>, <a class="iref" href="#rfc.iref.h.9"><b>8.6</b></a>, <a class="iref" href="#rfc.xref.header.trailer.3">9.1</a></li>
    3212                         <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">4.3</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.3">4.4</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.4">4.5</a>, <a class="iref" href="#rfc.iref.h.10"><b>8.7</b></a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.5">9.1</a></li>
    3213                         <li class="indline1">Upgrade&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.upgrade.1">4.5</a>, <a class="iref" href="#rfc.iref.h.11"><b>8.8</b></a>, <a class="iref" href="#rfc.xref.header.upgrade.2">9.1</a></li>
    3214                         <li class="indline1">Via&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.via.1">4.5</a>, <a class="iref" href="#rfc.iref.h.12"><b>8.9</b></a>, <a class="iref" href="#rfc.xref.header.via.2">9.1</a></li>
     3210                        <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.8"><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>
     3211                        <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.9"><b>8.6</b></a>, <a class="iref" href="#rfc.xref.header.trailer.3">9.1</a></li>
     3212                        <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.10"><b>8.7</b></a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.5">9.1</a></li>
     3213                        <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.11"><b>8.8</b></a>, <a class="iref" href="#rfc.xref.header.upgrade.2">9.1</a></li>
     3214                        <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.12"><b>8.9</b></a>, <a class="iref" href="#rfc.xref.header.via.2">9.1</a></li>
    32153215                     </ul>
    32163216                  </li>
    32173217                  <li class="indline1">Host header&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.6"><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>
    3218                   <li class="indline1">http URI scheme&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.1"><b>2.1.1</b></a></li>
    3219                   <li class="indline1">https URI scheme&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.2">2.1.2</a></li>
     3218                  <li class="indline1">http URI scheme&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.1"><b>2.3.1</b></a></li>
     3219                  <li class="indline1">https URI scheme&nbsp;&nbsp;<a class="iref" href="#rfc.iref.h.2">2.3.2</a></li>
    32203220               </ul>
    32213221            </li>
    32223222            <li class="indline0"><a id="rfc.index.I" href="#rfc.index.I"><b>I</b></a><ul class="ind">
    32233223                  <li class="indline1">inbound&nbsp;&nbsp;<a class="iref" href="#rfc.iref.i.1">C</a></li>
    3224                   <li class="indline1"><em>ISO-8859-1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.ISO-8859-1.1">4.2</a>, <a class="iref" href="#ISO-8859-1"><b>12.1</b></a></li>
     3224                  <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>
    32253225               </ul>
    32263226            </li>
    32273227            <li class="indline0"><a id="rfc.index.K" href="#rfc.index.K"><b>K</b></a><ul class="ind">
    3228                   <li class="indline1"><em>Kri2001</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Kri2001.1">4.2</a>, <a class="iref" href="#Kri2001"><b>12.2</b></a></li>
     3228                  <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>
    32293229               </ul>
    32303230            </li>
    … …  
    32513251            <li class="indline0"><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul class="ind">
    32523252                  <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>
    3253                   <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">5</a>, <a class="iref" href="#rfc.xref.Part2.4">5.1.2</a>, <a class="iref" href="#rfc.xref.Part2.5">5.1.2</a>, <a class="iref" href="#rfc.xref.Part2.6">6</a>, <a class="iref" href="#rfc.xref.Part2.7">6.1.1</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">
    3254                         <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">5</a></li>
    3255                         <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">6</a></li>
     3253                  <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">
     3254                        <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>
     3255                        <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>
    32563256                        <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>
    3257                         <li class="indline1"><em>Section 7.9</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.4">5.1.2</a></li>
    3258                         <li class="indline1"><em>Section 8</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.7">6.1.1</a></li>
     3257                        <li class="indline1"><em>Section 7.9</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.4">4.1.2</a></li>
     3258                        <li class="indline1"><em>Section 8</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.7">5.1.1</a></li>
    32593259                        <li class="indline1"><em>Section 8.1.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.10">7.2.3</a></li>
    32603260                        <li class="indline1"><em>Section 8.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.13">7.2.3</a></li>
    3261                         <li class="indline1"><em>Section 8.4.15</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.5">5.1.2</a></li>
     3261                        <li class="indline1"><em>Section 8.4.15</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part2.5">4.1.2</a></li>
    32623262                        <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>
    32633263                     </ul>
    32643264                  </li>
    3265                   <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">3.3</a>, <a class="iref" href="#rfc.xref.Part3.6">3.3</a>, <a class="iref" href="#rfc.xref.Part3.7">3.5</a>, <a class="iref" href="#rfc.xref.Part3.8">5</a>, <a class="iref" href="#rfc.xref.Part3.9">6</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">
    3266                         <li class="indline1"><em>Section 2.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.5">3.3</a>, <a class="iref" href="#rfc.xref.Part3.6">3.3</a></li>
     3265                  <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">
     3266                        <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>
    32673267                        <li class="indline1"><em>Section 2.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.2">1.2.2</a></li>
    3268                         <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.Part3.8">5</a>, <a class="iref" href="#rfc.xref.Part3.9">6</a></li>
     3268                        <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>
    32693269                        <li class="indline1"><em>Section 3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.13">C</a></li>
    32703270                        <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.3">1.2.3</a></li>
    3271                         <li class="indline1"><em>Section 4</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.7">3.5</a>, <a class="iref" href="#rfc.xref.Part3.12">C</a>, <a class="iref" href="#rfc.xref.Part3.14">C</a></li>
     3271                        <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>
    32723272                        <li class="indline1"><em>Appendix A</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part3.1">1</a></li>
    32733273                     </ul>
    32743274                  </li>
    32753275                  <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>
    3276                   <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">2.2</a>, <a class="iref" href="#rfc.xref.Part6.5">4.5</a>, <a class="iref" href="#rfc.xref.Part6.6">4.5</a>, <a class="iref" href="#rfc.xref.Part6.7">4.5</a>, <a class="iref" href="#Part6"><b>12.1</b></a>, <a class="iref" href="#rfc.xref.Part6.8">B.3</a>, <a class="iref" href="#rfc.xref.Part6.9">C</a><ul class="ind">
    3277                         <li class="indline1"><em>Section 1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.4">2.2</a>, <a class="iref" href="#rfc.xref.Part6.9">C</a></li>
    3278                         <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.5">4.5</a></li>
    3279                         <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">4.5</a></li>
    3280                         <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">4.5</a></li>
     3276                  <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">2.1</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>, <a class="iref" href="#rfc.xref.Part6.9">C</a><ul class="ind">
     3277                        <li class="indline1"><em>Section 1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.4">2.1</a>, <a class="iref" href="#rfc.xref.Part6.9">C</a></li>
     3278                        <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.5">3.5</a></li>
     3279                        <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>
     3280                        <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>
    32813281                     </ul>
    32823282                  </li>
    … …  
    32873287                  <li class="indline1">representation&nbsp;&nbsp;<a class="iref" href="#rfc.iref.r.4">C</a></li>
    32883288                  <li class="indline1">request&nbsp;&nbsp;<a class="iref" href="#rfc.iref.r.2">C</a></li>
    3289                   <li class="indline1">resource&nbsp;&nbsp;<a class="iref" href="#rfc.iref.r.1"><b>2.1</b></a></li>
     3289                  <li class="indline1">resource&nbsp;&nbsp;<a class="iref" href="#rfc.iref.r.1"><b>2.3</b></a></li>
    32903290                  <li class="indline1">response&nbsp;&nbsp;<a class="iref" href="#rfc.iref.r.3">C</a></li>
    3291                   <li class="indline1"><em>RFC1123</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC1123.1">3.2</a>, <a class="iref" href="#RFC1123"><b>12.2</b></a></li>
     3291                  <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>
    32923292                  <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>
    32933293                  <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>
    32943294                  <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>
    3295                   <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">3.3</a>, <a class="iref" href="#rfc.xref.RFC2045.3">11</a>, <a class="iref" href="#RFC2045"><b>12.2</b></a></li>
    3296                   <li class="indline1"><em>RFC2047</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2047.1">4.2</a>, <a class="iref" href="#RFC2047"><b>12.2</b></a></li>
    3297                   <li class="indline1"><em>RFC2068</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2068.1">3.1</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">
     3295                  <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></li>
     3296                  <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>
     3297                  <li class="indline1"><em>RFC2068</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2068.1">2.2</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">
    32983298                        <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>
    32993299                     </ul>
    33003300                  </li>
    3301                   <li class="indline1"><em>RFC2109</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2109.1">4.2</a>, <a class="iref" href="#RFC2109"><b>12.2</b></a></li>
     3301                  <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>
    33023302                  <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>
    3303                   <li class="indline1"><em>RFC2145</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2145.1">3.1</a>, <a class="iref" href="#rfc.xref.RFC2145.2">3.1</a>, <a class="iref" href="#RFC2145"><b>12.2</b></a>, <a class="iref" href="#rfc.xref.RFC2145.3">B.3</a></li>
     3303                  <li class="indline1"><em>RFC2145</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2145.1">2.2</a>, <a class="iref" href="#rfc.xref.RFC2145.2">2.2</a>, <a class="iref" href="#RFC2145"><b>12.2</b></a>, <a class="iref" href="#rfc.xref.RFC2145.3">B.3</a></li>
    33043304                  <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>
    3305                   <li class="indline1"><em>RFC2818</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2818.1">2.1.2</a>, <a class="iref" href="#RFC2818"><b>12.2</b></a></li>
    3306                   <li class="indline1"><em>RFC2965</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2965.1">4.2</a>, <a class="iref" href="#RFC2965"><b>12.2</b></a></li>
     3305                  <li class="indline1"><em>RFC2818</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2818.1">2.3.2</a>, <a class="iref" href="#RFC2818"><b>12.2</b></a></li>
     3306                  <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>
    33073307                  <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>
    3308                   <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">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.3">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.4">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.5">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.6">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.7">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.8">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.9">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.10">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.11">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.12">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.13">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.14">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.15">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.16">2.1.1</a>, <a class="iref" href="#rfc.xref.RFC3986.17">2.1.3</a>, <a class="iref" href="#rfc.xref.RFC3986.18">2.1.3</a>, <a class="iref" href="#rfc.xref.RFC3986.19">5.1.2</a>, <a class="iref" href="#RFC3986"><b>12.1</b></a><ul class="ind">
    3309                         <li class="indline1"><em>Section 2.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.18">2.1.3</a>, <a class="iref" href="#rfc.xref.RFC3986.19">5.1.2</a></li>
    3310                         <li class="indline1"><em>Section 3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.5">2.1</a></li>
    3311                         <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.9">2.1</a></li>
    3312                         <li class="indline1"><em>Section 3.2.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.15">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.16">2.1.1</a></li>
    3313                         <li class="indline1"><em>Section 3.2.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.13">2.1</a></li>
    3314                         <li class="indline1"><em>Section 3.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.11">2.1</a>, <a class="iref" href="#rfc.xref.RFC3986.12">2.1</a></li>
    3315                         <li class="indline1"><em>Section 3.4</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.14">2.1</a></li>
    3316                         <li class="indline1"><em>Section 3.5</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.10">2.1</a></li>
    3317                         <li class="indline1"><em>Section 4.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.6">2.1</a></li>
    3318                         <li class="indline1"><em>Section 4.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.8">2.1</a></li>
    3319                         <li class="indline1"><em>Section 4.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.7">2.1</a></li>
    3320                         <li class="indline1"><em>Section 6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.17">2.1.3</a></li>
     3308                  <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">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.3">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.4">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.5">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.6">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.7">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.8">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.9">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.10">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.11">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.12">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.13">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.14">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.15">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.16">2.3.1</a>, <a class="iref" href="#rfc.xref.RFC3986.17">2.3.3</a>, <a class="iref" href="#rfc.xref.RFC3986.18">2.3.3</a>, <a class="iref" href="#rfc.xref.RFC3986.19">4.1.2</a>, <a class="iref" href="#RFC3986"><b>12.1</b></a><ul class="ind">
     3309                        <li class="indline1"><em>Section 2.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.18">2.3.3</a>, <a class="iref" href="#rfc.xref.RFC3986.19">4.1.2</a></li>
     3310                        <li class="indline1"><em>Section 3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.5">2.3</a></li>
     3311                        <li class="indline1"><em>Section 3.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.9">2.3</a></li>
     3312                        <li class="indline1"><em>Section 3.2.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.15">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.16">2.3.1</a></li>
     3313                        <li class="indline1"><em>Section 3.2.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.13">2.3</a></li>
     3314                        <li class="indline1"><em>Section 3.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.11">2.3</a>, <a class="iref" href="#rfc.xref.RFC3986.12">2.3</a></li>
     3315                        <li class="indline1"><em>Section 3.4</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.14">2.3</a></li>
     3316                        <li class="indline1"><em>Section 3.5</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.10">2.3</a></li>
     3317                        <li class="indline1"><em>Section 4.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.6">2.3</a></li>
     3318                        <li class="indline1"><em>Section 4.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.8">2.3</a></li>
     3319                        <li class="indline1"><em>Section 4.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.7">2.3</a></li>
     3320                        <li class="indline1"><em>Section 6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3986.17">2.3.3</a></li>
    33213321                     </ul>
    33223322                  </li>
    … …  
    33273327                     </ul>
    33283328                  </li>
    3329                   <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">3.2</a>, <a class="iref" href="#rfc.xref.RFC5322.3">4.1</a>, <a class="iref" href="#rfc.xref.RFC5322.4">4.2</a>, <a class="iref" href="#rfc.xref.RFC5322.5">8.3</a>, <a class="iref" href="#rfc.xref.RFC5322.6">8.9</a>, <a class="iref" href="#RFC5322"><b>12.2</b></a><ul class="ind">
    3330                         <li class="indline1"><em>Section 2.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.4">4.2</a></li>
    3331                         <li class="indline1"><em>Section 3.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.2">3.2</a></li>
     3329                  <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">3.1</a>, <a class="iref" href="#rfc.xref.RFC5322.3">3.2</a>, <a class="iref" href="#rfc.xref.RFC5322.4">6.1</a>, <a class="iref" href="#rfc.xref.RFC5322.5">8.3</a>, <a class="iref" href="#rfc.xref.RFC5322.6">8.9</a>, <a class="iref" href="#RFC5322"><b>12.2</b></a><ul class="ind">
     3330                        <li class="indline1"><em>Section 2.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.3">3.2</a></li>
     3331                        <li class="indline1"><em>Section 3.3</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.4">6.1</a></li>
    33323332                        <li class="indline1"><em>Section 3.6.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.5">8.3</a></li>
    33333333                        <li class="indline1"><em>Section 3.6.7</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5322.6">8.9</a></li>
    … …  
    33423342            </li>
    33433343            <li class="indline0"><a id="rfc.index.T" href="#rfc.index.T"><b>T</b></a><ul class="ind">
    3344                   <li class="indline1">TE header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.te.1">3.3</a>, <a class="iref" href="#rfc.xref.header.te.2">3.3.1</a>, <a class="iref" href="#rfc.xref.header.te.3">3.5</a>, <a class="iref" href="#rfc.iref.t.1"><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>
     3344                  <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.1"><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>
    33453345                  <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>
    3346                   <li class="indline1">Trailer header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.trailer.1">3.3.1</a>, <a class="iref" href="#rfc.xref.header.trailer.2">4.5</a>, <a class="iref" href="#rfc.iref.t.2"><b>8.6</b></a>, <a class="iref" href="#rfc.xref.header.trailer.3">9.1</a></li>
    3347                   <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">4.3</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.3">4.4</a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.4">4.5</a>, <a class="iref" href="#rfc.iref.t.3"><b>8.7</b></a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.5">9.1</a></li>
     3346                  <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.2"><b>8.6</b></a>, <a class="iref" href="#rfc.xref.header.trailer.3">9.1</a></li>
     3347                  <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.3"><b>8.7</b></a>, <a class="iref" href="#rfc.xref.header.transfer-encoding.5">9.1</a></li>
    33483348                  <li class="indline1">tunnel&nbsp;&nbsp;<a class="iref" href="#rfc.iref.t.4">C</a></li>
    33493349               </ul>
    33503350            </li>
    33513351            <li class="indline0"><a id="rfc.index.U" href="#rfc.index.U"><b>U</b></a><ul class="ind">
    3352                   <li class="indline1">Upgrade header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.upgrade.1">4.5</a>, <a class="iref" href="#rfc.iref.u.3"><b>8.8</b></a>, <a class="iref" href="#rfc.xref.header.upgrade.2">9.1</a></li>
     3352                  <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.3"><b>8.8</b></a>, <a class="iref" href="#rfc.xref.header.upgrade.2">9.1</a></li>
    33533353                  <li class="indline1">upstream&nbsp;&nbsp;<a class="iref" href="#rfc.iref.u.4">C</a></li>
    33543354                  <li class="indline1">URI scheme&nbsp;&nbsp;
    33553355                     <ul class="ind">
    3356                         <li class="indline1">http&nbsp;&nbsp;<a class="iref" href="#rfc.iref.u.1"><b>2.1.1</b></a></li>
    3357                         <li class="indline1">https&nbsp;&nbsp;<a class="iref" href="#rfc.iref.u.2">2.1.2</a></li>
     3356                        <li class="indline1">http&nbsp;&nbsp;<a class="iref" href="#rfc.iref.u.1"><b>2.3.1</b></a></li>
     3357                        <li class="indline1">https&nbsp;&nbsp;<a class="iref" href="#rfc.iref.u.2">2.3.2</a></li>
    33583358                     </ul>
    33593359                  </li>
    3360                   <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">4.2</a>, <a class="iref" href="#USASCII"><b>12.1</b></a></li>
     3360                  <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>
    33613361                  <li class="indline1">user agent&nbsp;&nbsp;<a class="iref" href="#rfc.iref.u.5">C</a></li>
    33623362               </ul>
    … …  
    33643364            <li class="indline0"><a id="rfc.index.V" href="#rfc.index.V"><b>V</b></a><ul class="ind">
    33653365                  <li class="indline1">variant&nbsp;&nbsp;<a class="iref" href="#rfc.iref.v.2">C</a></li>
    3366                   <li class="indline1">Via header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.via.1">4.5</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>
     3366                  <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>
    33673367               </ul>
    33683368            </li>
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