Ignore:
Timestamp:
Nov 4, 2012, 9:10:11 PM (7 years ago)
Author:
fielding@…
Message:

Update charset terminology to the latest BCPs and remove duplicate or antiquated references to IETF requirements

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1 edited

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

    r1974 r1975  
    449449  }
    450450  @bottom-center {
    451        content: "Expires May 8, 2013";
     451       content: "Expires May 9, 2013";
    452452  }
    453453  @bottom-right {
     
    496496      <meta name="dct.creator" content="Reschke, J. F.">
    497497      <meta name="dct.identifier" content="urn:ietf:id:draft-ietf-httpbis-p2-semantics-latest">
    498       <meta name="dct.issued" scheme="ISO8601" content="2012-11-04">
     498      <meta name="dct.issued" scheme="ISO8601" content="2012-11-05">
    499499      <meta name="dct.replaces" content="urn:ietf:rfc:2616">
    500500      <meta name="dct.abstract" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypertext information systems. This document defines the semantics of HTTP/1.1 messages, as expressed by request methods, request header fields, response status codes, and response header fields, along with the payload of messages (metadata and body content) and mechanisms for content negotiation.">
     
    524524            <tr>
    525525               <td class="left">Intended status: Standards Track</td>
    526                <td class="right">November 4, 2012</td>
     526               <td class="right">November 5, 2012</td>
    527527            </tr>
    528528            <tr>
    529                <td class="left">Expires: May 8, 2013</td>
     529               <td class="left">Expires: May 9, 2013</td>
    530530               <td class="right"></td>
    531531            </tr>
     
    555555         in progress”.
    556556      </p>
    557       <p>This Internet-Draft will expire on May 8, 2013.</p>
     557      <p>This Internet-Draft will expire on May 9, 2013.</p>
    558558      <h1><a id="rfc.copyrightnotice" href="#rfc.copyrightnotice">Copyright Notice</a></h1>
    559559      <p>Copyright © 2012 IETF Trust and the persons identified as the document authors. All rights reserved.</p>
     
    582582               <li><a href="#rfc.section.3.1">3.1</a>&nbsp;&nbsp;&nbsp;<a href="#representation.metadata">Representation Metadata</a><ul>
    583583                     <li><a href="#rfc.section.3.1.1">3.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#data.type">Data Type</a><ul>
    584                            <li><a href="#rfc.section.3.1.1.1">3.1.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#media.types">Media Types</a></li>
    585                            <li><a href="#rfc.section.3.1.1.2">3.1.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#character.sets">Character Encodings (charset)</a></li>
     584                           <li><a href="#rfc.section.3.1.1.1">3.1.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#media.type">Media Type</a></li>
     585                           <li><a href="#rfc.section.3.1.1.2">3.1.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#charset">Charset</a></li>
    586586                           <li><a href="#rfc.section.3.1.1.3">3.1.1.3</a>&nbsp;&nbsp;&nbsp;<a href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></li>
    587587                           <li><a href="#rfc.section.3.1.1.4">3.1.1.4</a>&nbsp;&nbsp;&nbsp;<a href="#multipart.types">Multipart Types</a></li>
     
    827827      <p id="rfc.section.1.2.p.1">This specification uses the Augmented Backus-Naur Form (ABNF) notation of <a href="#RFC5234" id="rfc.xref.RFC5234.1"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a> with the list rule extension defined in <a href="p1-messaging.html#notation" title="Syntax Notation">Section 1.2</a> of <a href="#Part1" id="rfc.xref.Part1.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>. <a href="#imported.abnf" title="Imported ABNF">Appendix&nbsp;D</a> describes rules imported from other documents. <a href="#collected.abnf" title="Collected ABNF">Appendix&nbsp;E</a> shows the collected ABNF with the list rule expanded.
    828828      </p>
     829      <p id="rfc.section.1.2.p.2">This specification uses the terms "character", "character encoding scheme", "charset", and "protocol element" as they are
     830         defined in <a href="#RFC6365" id="rfc.xref.RFC6365.1"><cite title="Terminology Used in Internationalization in the IETF">[RFC6365]</cite></a>.
     831      </p>
    829832      <h1 id="rfc.section.2"><a href="#rfc.section.2">2.</a>&nbsp;<a id="resource" href="#resource">Resource</a></h1>
    830833      <p id="rfc.section.2.p.1">The target of each HTTP request is called a resource. HTTP does not limit the nature of a resource; it merely defines an interface
     
    888891      </div>
    889892      <h3 id="rfc.section.3.1.1"><a href="#rfc.section.3.1.1">3.1.1</a>&nbsp;<a id="data.type" href="#data.type">Data Type</a></h3>
    890       <h4 id="rfc.section.3.1.1.1"><a href="#rfc.section.3.1.1.1">3.1.1.1</a>&nbsp;<a id="media.types" href="#media.types">Media Types</a></h4>
     893      <h4 id="rfc.section.3.1.1.1"><a href="#rfc.section.3.1.1.1">3.1.1.1</a>&nbsp;<a id="media.type" href="#media.type">Media Type</a></h4>
    891894      <p id="rfc.section.3.1.1.1.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> in the <a href="#header.content-type" class="smpl">Content-Type</a> (<a href="#header.content-type" id="rfc.xref.header.content-type.2" title="Content-Type">Section&nbsp;3.1.1.5</a>) and <a href="#header.accept" class="smpl">Accept</a> (<a href="#header.accept" id="rfc.xref.header.accept.1" title="Accept">Section&nbsp;6.3.2</a>) header fields in order to provide open and extensible data typing and type negotiation.
    892895      </p>
    893       <div id="rfc.figure.u.1"></div><pre class="inline"><span id="rfc.iref.g.1"></span><span id="rfc.iref.g.2"></span><span id="rfc.iref.g.3"></span>  <a href="#media.types" class="smpl">media-type</a> = <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> *( <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> )
    894   <a href="#media.types" class="smpl">type</a>       = <a href="#imported.abnf" class="smpl">token</a>
    895   <a href="#media.types" class="smpl">subtype</a>    = <a href="#imported.abnf" class="smpl">token</a>
     896      <div id="rfc.figure.u.1"></div><pre class="inline"><span id="rfc.iref.g.1"></span><span id="rfc.iref.g.2"></span><span id="rfc.iref.g.3"></span>  <a href="#media.type" class="smpl">media-type</a> = <a href="#media.type" class="smpl">type</a> "/" <a href="#media.type" class="smpl">subtype</a> *( <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> )
     897  <a href="#media.type" class="smpl">type</a>       = <a href="#imported.abnf" class="smpl">token</a>
     898  <a href="#media.type" class="smpl">subtype</a>    = <a href="#imported.abnf" class="smpl">token</a>
    896899</pre><div id="rule.parameter">
    897900         <p id="rfc.section.3.1.1.1.p.3">      The type/subtype <em class="bcp14">MAY</em> be followed by parameters in the form of attribute/value pairs.
     
    906909      </p>
    907910      <p id="rfc.section.3.1.1.1.p.6">A parameter value that matches the <a href="#imported.abnf" class="smpl">token</a> production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent.
    908       </p>
    909       <p id="rfc.section.3.1.1.1.p.7">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is
     911         For example, the following examples are all equivalent, but the first is preferred for consistency:
     912      </p>
     913      <div id="rfc.figure.u.3"></div><pre class="text">  text/html;charset=utf-8
     914  text/html;charset=UTF-8
     915  Text/HTML;Charset="utf-8"
     916  text/html; charset="utf-8"
     917</pre><p id="rfc.section.3.1.1.1.p.8">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is
    910918         outlined in <a href="#RFC4288" id="rfc.xref.RFC4288.1"><cite title="Media Type Specifications and Registration Procedures">[RFC4288]</cite></a>. Use of non-registered media types is discouraged.
    911919      </p>
    912       <h4 id="rfc.section.3.1.1.2"><a href="#rfc.section.3.1.1.2">3.1.1.2</a>&nbsp;<a id="character.sets" href="#character.sets">Character Encodings (charset)</a></h4>
    913       <p id="rfc.section.3.1.1.2.p.1">HTTP uses charset names to indicate the character encoding of a textual representation.</p>
    914       <div id="rule.charset">
    915          <p id="rfc.section.3.1.1.2.p.2">  A character encoding is identified by a case-insensitive token. The complete set of tokens is defined by the IANA Character
    916             Set registry (&lt;<a href="http://www.iana.org/assignments/character-sets">http://www.iana.org/assignments/character-sets</a>&gt;).
    917          </p>
    918       </div>
    919       <div id="rfc.figure.u.3"></div><pre class="inline"><span id="rfc.iref.g.7"></span>  <a href="#rule.charset" class="smpl">charset</a> = <a href="#imported.abnf" class="smpl">token</a>
    920 </pre><p id="rfc.section.3.1.1.2.p.4">Although HTTP allows an arbitrary token to be used as a charset value, any token that has a predefined value within the IANA
    921          Character Set registry <em class="bcp14">MUST</em> represent the character encoding defined by that registry. Applications <em class="bcp14">SHOULD</em> limit their use of character encodings to those defined within the IANA registry.
    922       </p>
    923       <p id="rfc.section.3.1.1.2.p.5">HTTP uses charset in two contexts: within an <a href="#header.accept-charset" class="smpl">Accept-Charset</a> request header field (in which the charset value is an unquoted token) and as the value of a parameter in a <a href="#header.content-type" class="smpl">Content-Type</a> header field (within a request or response), in which case the parameter value of the charset parameter can be quoted.
    924       </p>
    925       <p id="rfc.section.3.1.1.2.p.6">Implementers need to be aware of IETF character set requirements <a href="#RFC3629" id="rfc.xref.RFC3629.1"><cite title="UTF-8, a transformation format of ISO 10646">[RFC3629]</cite></a>  <a href="#RFC2277" id="rfc.xref.RFC2277.1"><cite title="IETF Policy on Character Sets and Languages">[RFC2277]</cite></a>.
     920      <h4 id="rfc.section.3.1.1.2"><a href="#rfc.section.3.1.1.2">3.1.1.2</a>&nbsp;<a id="charset" href="#charset">Charset</a></h4>
     921      <p id="rfc.section.3.1.1.2.p.1">HTTP uses charset names to indicate or negotiate the character encoding scheme of a textual representation <a href="#RFC6365" id="rfc.xref.RFC6365.2"><cite title="Terminology Used in Internationalization in the IETF">[RFC6365]</cite></a>. A charset is identified by a case-insensitive token.
     922      </p>
     923      <div id="rfc.figure.u.4"></div><pre class="inline"><span id="rfc.iref.g.7"></span>  <a href="#charset" class="smpl">charset</a> = <a href="#imported.abnf" class="smpl">token</a>
     924</pre><p id="rfc.section.3.1.1.2.p.3">The IANA Character Set registry (&lt;<a href="http://www.iana.org/assignments/character-sets">http://www.iana.org/assignments/character-sets</a>&gt;) maintains the set of tokens registered for use on the Internet as charset names <a href="#RFC2978" id="rfc.xref.RFC2978.1"><cite title="IANA Charset Registration Procedures">[RFC2978]</cite></a>.
    926925      </p>
    927926      <h4 id="rfc.section.3.1.1.3"><a href="#rfc.section.3.1.1.3">3.1.1.3</a>&nbsp;<a id="canonicalization.and.text.defaults" href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></h4>
     
    931930         allows the transport of text media with plain CR or LF alone representing a line break when it is done consistently for an
    932931         entire representation. HTTP applications <em class="bcp14">MUST</em> accept CRLF, bare CR, and bare LF as indicating a line break in text media received via HTTP. In addition, if the text is
    933          in a character encoding that does not use octets 13 and 10 for CR and LF respectively, as is the case for some multi-byte
    934          character encodings, HTTP allows the use of whatever octet sequences are defined by that character encoding to represent the
    935          equivalent of CR and LF for line breaks. This flexibility regarding line breaks applies only to text media in the payload
    936          body; a bare CR or LF <em class="bcp14">MUST NOT</em> be substituted for CRLF within any of the HTTP control structures (such as header fields and multipart boundaries).
     932         in a charset that does not use octets 13 and 10 for CR and LF respectively, as is the case for some multi-byte charsets, HTTP
     933         allows the use of whatever octet sequences are defined by that charset to represent the equivalent of CR and LF for line breaks.
     934         This flexibility regarding line breaks applies only to text media in the payload body; a bare CR or LF <em class="bcp14">MUST NOT</em> be substituted for CRLF within any of the HTTP control structures (such as header fields and multipart boundaries).
    937935      </p>
    938936      <p id="rfc.section.3.1.1.3.p.3">If a representation is encoded with a content-coding, the underlying data <em class="bcp14">MUST</em> be in a form defined above prior to being encoded.
     
    958956         that data <em class="bcp14">SHOULD</em> be processed by the recipient (within the scope of the request method semantics) after any <a href="#header.content-encoding" class="smpl">Content-Encoding</a> is decoded. For responses to the HEAD method, the media type is that which would have been sent had the request been a GET.
    959957      </p>
    960       <div id="rfc.figure.u.4"></div><pre class="inline"><span id="rfc.iref.g.8"></span>  <a href="#header.content-type" class="smpl">Content-Type</a> = <a href="#media.types" class="smpl">media-type</a>
    961 </pre><p id="rfc.section.3.1.1.5.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section&nbsp;3.1.1.1</a>. An example of the field is
    962       </p>
    963       <div id="rfc.figure.u.5"></div><pre class="text">  Content-Type: text/html; charset=ISO-8859-4
     958      <div id="rfc.figure.u.5"></div><pre class="inline"><span id="rfc.iref.g.8"></span>  <a href="#header.content-type" class="smpl">Content-Type</a> = <a href="#media.type" class="smpl">media-type</a>
     959</pre><p id="rfc.section.3.1.1.5.p.3">Media types are defined in <a href="#media.type" title="Media Type">Section&nbsp;3.1.1.1</a>. An example of the field is
     960      </p>
     961      <div id="rfc.figure.u.6"></div><pre class="text">  Content-Type: text/html; charset=ISO-8859-4
    964962</pre><p id="rfc.section.3.1.1.5.p.5">A sender <em class="bcp14">SHOULD</em> include a Content-Type header field in a message containing a payload body, defining the media type of the enclosed representation,
    965963         unless the intended media type is unknown to the sender. If a Content-Type header field is not present, recipients <em class="bcp14">MAY</em> either assume a media type of "application/octet-stream" (<a href="#RFC2046" id="rfc.xref.RFC2046.3"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, <a href="http://tools.ietf.org/html/rfc2046#section-4.5.1">Section 4.5.1</a>) or examine the representation data to determine its type.
     
    985983         directly, and only decoded by the recipient.
    986984      </p>
    987       <div id="rfc.figure.u.6"></div><pre class="inline"><span id="rfc.iref.g.10"></span>  <a href="#content.codings" class="smpl">content-coding</a>   = <a href="#imported.abnf" class="smpl">token</a>
     985      <div id="rfc.figure.u.7"></div><pre class="inline"><span id="rfc.iref.g.10"></span>  <a href="#content.codings" class="smpl">content-coding</a>   = <a href="#imported.abnf" class="smpl">token</a>
    988986</pre><p id="rfc.section.3.1.2.1.p.3">All content-coding values are case-insensitive and <em class="bcp14">SHOULD</em> be registered within the HTTP Content Coding registry, as defined in <a href="#content.coding.registry" title="Content Coding Registry">Section&nbsp;9.4</a>. They are used in the <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.1" title="Accept-Encoding">Section&nbsp;6.3.4</a>) and <a href="#header.content-encoding" class="smpl">Content-Encoding</a> (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.2" title="Content-Encoding">Section&nbsp;3.1.2.2</a>) header fields.
    989987      </p>
     
    10041002         of its underlying media type.
    10051003      </p>
    1006       <div id="rfc.figure.u.7"></div><pre class="inline"><span id="rfc.iref.g.11"></span>  <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = 1#<a href="#content.codings" class="smpl">content-coding</a>
     1004      <div id="rfc.figure.u.8"></div><pre class="inline"><span id="rfc.iref.g.11"></span>  <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = 1#<a href="#content.codings" class="smpl">content-coding</a>
    10071005</pre><p id="rfc.section.3.1.2.2.p.3">An example of its use is</p>
    1008       <div id="rfc.figure.u.8"></div><pre class="text">  Content-Encoding: gzip
     1006      <div id="rfc.figure.u.9"></div><pre class="text">  Content-Encoding: gzip
    10091007</pre><p id="rfc.section.3.1.2.2.p.5">If multiple encodings have been applied to a representation, the content codings <em class="bcp14">MUST</em> be listed in the order in which they were applied. Additional information about the encoding parameters <em class="bcp14">MAY</em> be provided by other header fields not defined by this specification.
    10101008      </p>
     
    10331031         of subtags:
    10341032      </p>
    1035       <div id="rfc.figure.u.9"></div><pre class="inline"><span id="rfc.iref.g.12"></span>  <a href="#language.tags" class="smpl">language-tag</a> = &lt;Language-Tag, defined in <a href="#RFC5646" id="rfc.xref.RFC5646.2"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, <a href="http://tools.ietf.org/html/rfc5646#section-2.1">Section 2.1</a>&gt;
     1033      <div id="rfc.figure.u.10"></div><pre class="inline"><span id="rfc.iref.g.12"></span>  <a href="#language.tags" class="smpl">language-tag</a> = &lt;Language-Tag, defined in <a href="#RFC5646" id="rfc.xref.RFC5646.2"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, <a href="http://tools.ietf.org/html/rfc5646#section-2.1">Section 2.1</a>&gt;
    10361034</pre><p id="rfc.section.3.1.3.1.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered
    10371035         by the IANA (see &lt;<a href="http://www.iana.org/assignments/language-subtag-registry">http://www.iana.org/assignments/language-subtag-registry</a>&gt;).
    10381036      </p>
    1039       <div id="rfc.figure.u.10"></div>
     1037      <div id="rfc.figure.u.11"></div>
    10401038      <p>Example tags include:</p>  <pre class="text">  en, en-US, es-419, az-Arab, x-pig-latin, man-Nkoo-GN
    10411039</pre> <p id="rfc.section.3.1.3.1.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information.
     
    10461044         that this might not be equivalent to all the languages used within the representation.
    10471045      </p>
    1048       <div id="rfc.figure.u.11"></div><pre class="inline"><span id="rfc.iref.g.13"></span>  <a href="#header.content-language" class="smpl">Content-Language</a> = 1#<a href="#language.tags" class="smpl">language-tag</a>
     1046      <div id="rfc.figure.u.12"></div><pre class="inline"><span id="rfc.iref.g.13"></span>  <a href="#header.content-language" class="smpl">Content-Language</a> = 1#<a href="#language.tags" class="smpl">language-tag</a>
    10491047</pre><p id="rfc.section.3.1.3.2.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;3.1.3.1</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the
    10501048         users' own preferred language. Thus, if the content is intended only for a Danish-literate audience, the appropriate field
    10511049         is
    10521050      </p>
    1053       <div id="rfc.figure.u.12"></div><pre class="text">  Content-Language: da
     1051      <div id="rfc.figure.u.13"></div><pre class="text">  Content-Language: da
    10541052</pre><p id="rfc.section.3.1.3.2.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean
    10551053         that the sender does not consider it to be specific to any natural language, or that the sender does not know for which language
     
    10591057         simultaneously in the original Maori and English versions, would call for
    10601058      </p>
    1061       <div id="rfc.figure.u.13"></div><pre class="text">  Content-Language: mi, en
     1059      <div id="rfc.figure.u.14"></div><pre class="text">  Content-Language: mi, en
    10621060</pre><p id="rfc.section.3.1.3.2.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple
    10631061         linguistic audiences. An example would be a beginner's language primer, such as "A First Lesson in Latin", which is clearly
     
    11021100         message payload. In other words, if one were to perform a GET on this URI at the time of this message's generation, then a <a href="#status.200" class="smpl">200 (OK)</a> response would contain the same representation that is enclosed as payload in this message.
    11031101      </p>
    1104       <div id="rfc.figure.u.14"></div><pre class="inline"><span id="rfc.iref.g.14"></span>  <a href="#header.content-location" class="smpl">Content-Location</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a>
     1102      <div id="rfc.figure.u.15"></div><pre class="inline"><span id="rfc.iref.g.14"></span>  <a href="#header.content-location" class="smpl">Content-Location</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a>
    11051103</pre><p id="rfc.section.3.1.4.2.p.3">The Content-Location value is not a replacement for the effective Request URI (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 5.5</a> of <a href="#Part1" id="rfc.xref.Part1.12"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>). It is representation metadata. It has the same syntax and semantics as the header field of the same name defined for MIME
    11061104         body parts in <a href="http://tools.ietf.org/html/rfc2557#section-4">Section 4</a> of <a href="#RFC2557" id="rfc.xref.RFC2557.1"><cite title="MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)">[RFC2557]</cite></a>. However, its appearance in an HTTP message has some special implications for HTTP recipients.
     
    11491147      <p id="rfc.section.3.2.p.2">The data type of the representation data is determined via the header fields <a href="#header.content-type" class="smpl">Content-Type</a> and <a href="#header.content-encoding" class="smpl">Content-Encoding</a>. These define a two-layer, ordered encoding model:
    11501148      </p>
    1151       <div id="rfc.figure.u.15"></div><pre class="text">  representation-data := Content-Encoding( Content-Type( bits ) )
     1149      <div id="rfc.figure.u.16"></div><pre class="text">  representation-data := Content-Encoding( Content-Type( bits ) )
    11521150</pre><div id="rfc.iref.p.1"></div>
    11531151      <h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="payload" href="#payload">Payload Semantics</a></h2>
     
    11961194      <p id="rfc.section.3.4.p.1">HTTP responses include a representation which contains information for interpretation, whether by a human user or for further
    11971195         processing. Often, the server has different ways of representing the same information; for example, in different formats,
    1198          languages, or using different character encodings.
     1196         languages, or using different charsets.
    11991197      </p>
    12001198      <p id="rfc.section.3.4.p.2">HTTP clients and their users might have different or variable capabilities, characteristics or preferences which would influence
     
    12781276         By convention, the products are listed in order of their significance for identifying the application.
    12791277      </p>
    1280       <div id="rfc.figure.u.16"></div><pre class="inline"><span id="rfc.iref.g.15"></span><span id="rfc.iref.g.16"></span>  <a href="#product.tokens" class="smpl">product</a>         = <a href="#imported.abnf" class="smpl">token</a> ["/" <a href="#product.tokens" class="smpl">product-version</a>]
     1278      <div id="rfc.figure.u.17"></div><pre class="inline"><span id="rfc.iref.g.15"></span><span id="rfc.iref.g.16"></span>  <a href="#product.tokens" class="smpl">product</a>         = <a href="#imported.abnf" class="smpl">token</a> ["/" <a href="#product.tokens" class="smpl">product-version</a>]
    12811279  <a href="#product.tokens" class="smpl">product-version</a> = <a href="#imported.abnf" class="smpl">token</a>
    12821280</pre><p id="rfc.section.4.p.3">Examples:</p>
    1283       <div id="rfc.figure.u.17"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
     1281      <div id="rfc.figure.u.18"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
    12841282  Server: Apache/0.8.4
    12851283</pre><p id="rfc.section.4.p.5">Product tokens <em class="bcp14">SHOULD</em> be short and to the point. They <em class="bcp14">MUST NOT</em> be used for advertising or other non-essential information. Although any token octet <em class="bcp14">MAY</em> appear in a product-version, this token <em class="bcp14">SHOULD</em> only be used for a version identifier (i.e., successive versions of the same product <em class="bcp14">SHOULD</em> only differ in the product-version portion of the product value).
     
    12901288         this request and what is expected by the client as a successful result. The request semantics <em class="bcp14">MAY</em> be further specialized by the semantics of some header fields when present in a request (<a href="#request.header.fields" title="Request Header Fields">Section&nbsp;6</a>) if those additional semantics do not conflict with the method.
    12911289      </p>
    1292       <div id="rfc.figure.u.18"></div><pre class="inline"><span id="rfc.iref.g.17"></span>  <a href="#method.overview" class="smpl">method</a> = <a href="#imported.abnf" class="smpl">token</a>
     1290      <div id="rfc.figure.u.19"></div><pre class="inline"><span id="rfc.iref.g.17"></span>  <a href="#method.overview" class="smpl">method</a> = <a href="#imported.abnf" class="smpl">token</a>
    12931291</pre><p id="rfc.section.5.1.p.3">HTTP was originally designed to be usable as an interface to distributed object systems. The request method was envisioned
    12941292         as applying semantics to a target resource in much the same way as invoking a defined method on an identified object would
     
    15581556         For example,
    15591557      </p>
    1560       <div id="rfc.figure.u.19"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
     1558      <div id="rfc.figure.u.20"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
    15611559Host: server.example.com:80
    15621560
     
    15711569      </p>
    15721570      <p id="rfc.section.5.3.6.p.7">Proxy authentication might be used to establish the authority to create a tunnel:</p>
    1573       <div id="rfc.figure.u.20"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
     1571      <div id="rfc.figure.u.21"></div><pre class="text2">CONNECT server.example.com:80 HTTP/1.1
    15741572Host: server.example.com:80
    15751573Proxy-Authorization: basic aGVsbG86d29ybGQ=
     
    16641662         to trace a request which appears to be failing or looping mid-chain.
    16651663      </p>
    1666       <div id="rfc.figure.u.21"></div><pre class="inline"><span id="rfc.iref.g.19"></span>  <a href="#header.max-forwards" class="smpl">Max-Forwards</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
     1664      <div id="rfc.figure.u.22"></div><pre class="inline"><span id="rfc.iref.g.19"></span>  <a href="#header.max-forwards" class="smpl">Max-Forwards</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
    16671665</pre><p id="rfc.section.6.1.1.p.3">The Max-Forwards value is a decimal integer indicating the remaining number of times this request message can be forwarded.</p>
    16681666      <p id="rfc.section.6.1.1.p.4">Each recipient of a TRACE or OPTIONS request containing a Max-Forwards header field <em class="bcp14">MUST</em> check and update its value prior to forwarding the request. If the received value is zero (0), the recipient <em class="bcp14">MUST NOT</em> forward the request; instead, it <em class="bcp14">MUST</em> respond as the final recipient. If the received Max-Forwards value is greater than zero, then the forwarded message <em class="bcp14">MUST</em> contain an updated Max-Forwards field with a value decremented by one (1).
     
    16731671      <h3 id="rfc.section.6.1.2"><a href="#rfc.section.6.1.2">6.1.2</a>&nbsp;<a id="header.expect" href="#header.expect">Expect</a></h3>
    16741672      <p id="rfc.section.6.1.2.p.1">The "Expect" header field is used to indicate that particular server behaviors are required by the client.</p>
    1675       <div id="rfc.figure.u.22"></div><pre class="inline"><span id="rfc.iref.g.20"></span><span id="rfc.iref.g.21"></span><span id="rfc.iref.g.22"></span><span id="rfc.iref.g.23"></span><span id="rfc.iref.g.24"></span>  <a href="#header.expect" class="smpl">Expect</a>       = 1#<a href="#header.expect" class="smpl">expectation</a>
     1673      <div id="rfc.figure.u.23"></div><pre class="inline"><span id="rfc.iref.g.20"></span><span id="rfc.iref.g.21"></span><span id="rfc.iref.g.22"></span><span id="rfc.iref.g.23"></span><span id="rfc.iref.g.24"></span>  <a href="#header.expect" class="smpl">Expect</a>       = 1#<a href="#header.expect" class="smpl">expectation</a>
    16761674 
    16771675  <a href="#header.expect" class="smpl">expectation</a>  = <a href="#header.expect" class="smpl">expect-name</a> [ <a href="#imported.abnf" class="smpl">BWS</a> "=" <a href="#imported.abnf" class="smpl">BWS</a> <a href="#header.expect" class="smpl">expect-value</a> ]
     
    18191817         a value of 0 means "not acceptable". If no "q" parameter is present, the default weight is 1.
    18201818      </p>
    1821       <div id="rfc.figure.u.23"></div><pre class="inline"><span id="rfc.iref.g.25"></span><span id="rfc.iref.g.26"></span>  <a href="#quality.values" class="smpl">weight</a> = <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> "q=" <a href="#quality.values" class="smpl">qvalue</a>
     1819      <div id="rfc.figure.u.24"></div><pre class="inline"><span id="rfc.iref.g.25"></span><span id="rfc.iref.g.26"></span>  <a href="#quality.values" class="smpl">weight</a> = <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> "q=" <a href="#quality.values" class="smpl">qvalue</a>
    18221820  <a href="#quality.values" class="smpl">qvalue</a> = ( "0" [ "." 0*3<a href="#imported.abnf" class="smpl">DIGIT</a> ] )
    18231821         / ( "1" [ "." 0*3("0") ] )
     
    18311829         for an in-line image.
    18321830      </p>
    1833       <div id="rfc.figure.u.24"></div><pre class="inline"><span id="rfc.iref.g.27"></span><span id="rfc.iref.g.28"></span><span id="rfc.iref.g.29"></span><span id="rfc.iref.g.30"></span>  <a href="#header.accept" class="smpl">Accept</a> = #( <a href="#header.accept" class="smpl">media-range</a> [ <a href="#header.accept" class="smpl">accept-params</a> ] )
     1831      <div id="rfc.figure.u.25"></div><pre class="inline"><span id="rfc.iref.g.27"></span><span id="rfc.iref.g.28"></span><span id="rfc.iref.g.29"></span><span id="rfc.iref.g.30"></span>  <a href="#header.accept" class="smpl">Accept</a> = #( <a href="#header.accept" class="smpl">media-range</a> [ <a href="#header.accept" class="smpl">accept-params</a> ] )
    18341832 
    18351833  <a href="#header.accept" class="smpl">media-range</a>    = ( "*/*"
    1836                    / ( <a href="#media.types" class="smpl">type</a> "/" "*" )
    1837                    / ( <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> )
     1834                   / ( <a href="#media.type" class="smpl">type</a> "/" "*" )
     1835                   / ( <a href="#media.type" class="smpl">type</a> "/" <a href="#media.type" class="smpl">subtype</a> )
    18381836                   ) *( <a href="#imported.abnf" class="smpl">OWS</a> ";" <a href="#imported.abnf" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> )
    18391837  <a href="#header.accept" class="smpl">accept-params</a>  = <a href="#quality.values" class="smpl">weight</a> *( <a href="#header.accept" class="smpl">accept-ext</a> )
     
    18521850      </div>
    18531851      <p id="rfc.section.6.3.2.p.6">The example</p>
    1854       <div id="rfc.figure.u.25"></div><pre class="text">  Accept: audio/*; q=0.2, audio/basic
     1852      <div id="rfc.figure.u.26"></div><pre class="text">  Accept: audio/*; q=0.2, audio/basic
    18551853</pre><p id="rfc.section.6.3.2.p.8"> <em class="bcp14">SHOULD</em> be interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% mark-down in
    18561854         quality".
     
    18611859      </p>
    18621860      <p id="rfc.section.6.3.2.p.10">A more elaborate example is</p>
    1863       <div id="rfc.figure.u.26"></div><pre class="text">  Accept: text/plain; q=0.5, text/html,
     1861      <div id="rfc.figure.u.27"></div><pre class="text">  Accept: text/plain; q=0.5, text/html,
    18641862          text/x-dvi; q=0.8, text/x-c
    18651863</pre><p id="rfc.section.6.3.2.p.12">Verbally, this would be interpreted as "text/html and text/x-c are the preferred media types, but if they do not exist, then
     
    18691867         to a given type, the most specific reference has precedence. For example,
    18701868      </p>
    1871       <div id="rfc.figure.u.27"></div><pre class="text">  Accept: text/*, text/plain, text/plain;format=flowed, */*
     1869      <div id="rfc.figure.u.28"></div><pre class="text">  Accept: text/*, text/plain, text/plain;format=flowed, */*
    18721870</pre><p id="rfc.section.6.3.2.p.15">have the following precedence: </p>
    18731871      <ol>
     
    18801878         which matches that type. For example,
    18811879      </p>
    1882       <div id="rfc.figure.u.28"></div><pre class="text">  Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1,
     1880      <div id="rfc.figure.u.29"></div><pre class="text">  Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1,
    18831881          text/html;level=2;q=0.4, */*;q=0.5
    18841882</pre><p id="rfc.section.6.3.2.p.18">would cause the following values to be associated:</p>
     
    19241922      <div id="rfc.iref.a.2"></div>
    19251923      <h3 id="rfc.section.6.3.3"><a href="#rfc.section.6.3.3">6.3.3</a>&nbsp;<a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h3>
    1926       <p id="rfc.section.6.3.3.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response
    1927          payload. This field allows clients capable of understanding more comprehensive or special-purpose character encodings to signal
    1928          that capability to a server which is capable of representing documents in those character encodings.
    1929       </p>
    1930       <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.31"></span>  <a href="#header.accept-charset" class="smpl">Accept-Charset</a> = 1#( ( <a href="#rule.charset" class="smpl">charset</a> / "*" ) [ <a href="#quality.values" class="smpl">weight</a> ] )
    1931 </pre><p id="rfc.section.6.3.3.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section&nbsp;3.1.1.2</a>. Each charset <em class="bcp14">MAY</em> be given an associated quality value which represents the user's preference for that charset, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>. An example is
    1932       </p>
    1933       <div id="rfc.figure.u.30"></div><pre class="text">  Accept-Charset: iso-8859-5, unicode-1-1;q=0.8
    1934 </pre><p id="rfc.section.6.3.3.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere
    1935          in the Accept-Charset field. If no "*" is present in an Accept-Charset field, then any character encodings not explicitly
    1936          mentioned in the field are considered "not acceptable" to the client.
    1937       </p>
    1938       <p id="rfc.section.6.3.3.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response.</p>
    1939       <p id="rfc.section.6.3.3.p.7">If an Accept-Charset header field is present in a request and none of the available representations for the response have
    1940          a character encoding that is listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept-Charset header field by sending a <a href="#status.406" class="smpl">406 (Not Acceptable)</a> response or disregard the Accept-Charset header field by treating the response as if it is not subject to content negotiation.
     1924      <p id="rfc.section.6.3.3.p.1">The "Accept-Charset" header field can be sent by a user agent to indicate what charsets are acceptable in a selected representation.
     1925         This field allows user agents capable of understanding more comprehensive or special-purpose charsets to signal that capability
     1926         to an origin server which is capable of representing documents in those charsets.
     1927      </p>
     1928      <div id="rfc.figure.u.30"></div><pre class="inline"><span id="rfc.iref.g.31"></span>  <a href="#header.accept-charset" class="smpl">Accept-Charset</a> = 1#( ( <a href="#charset" class="smpl">charset</a> / "*" ) [ <a href="#quality.values" class="smpl">weight</a> ] )
     1929</pre><p id="rfc.section.6.3.3.p.3">Charset names are defined in <a href="#charset" title="Charset">Section&nbsp;3.1.1.2</a>. A user agent <em class="bcp14">MAY</em> associate a quality value with each charset to indicate the user's relative preference for that charset, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>. An example is
     1930      </p>
     1931      <div id="rfc.figure.u.31"></div><pre class="text">  Accept-Charset: iso-8859-5, unicode-1-1;q=0.8
     1932</pre><p id="rfc.section.6.3.3.p.5">The special value "*", if present in the Accept-Charset field, matches every charset which is not mentioned elsewhere in the
     1933         Accept-Charset field. If no "*" is present in an Accept-Charset field, then any charsets not explicitly mentioned in the field
     1934         are considered "not acceptable" to the client.
     1935      </p>
     1936      <p id="rfc.section.6.3.3.p.6">A request without any Accept-Charset header field implies that the user agent will accept any charset in response. Most general-purpose
     1937         user agents do not send Accept-Charset, unless specifically configured to do so, because a detailed list of supported charsets
     1938         makes it easier for a server to identify an individual by virtue of the user agent's request characteristics (a.k.a., fingerprinting).
     1939      </p>
     1940      <p id="rfc.section.6.3.3.p.7">If an Accept-Charset header field is present in a request and none of the available representations for the response has a
     1941         charset that is listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept-Charset header field, by sending a <a href="#status.406" class="smpl">406 (Not Acceptable)</a> response, or disregard the Accept-Charset header field by treating the resource as if it is not subject to content negotiation.
    19411942      </p>
    19421943      <div id="rfc.iref.a.3"></div>
     
    19451946         no encoding is preferred.
    19461947      </p>
    1947       <div id="rfc.figure.u.31"></div><pre class="inline"><span id="rfc.iref.g.32"></span><span id="rfc.iref.g.33"></span>  <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a>  = #( <a href="#header.accept-encoding" class="smpl">codings</a> [ <a href="#quality.values" class="smpl">weight</a> ] )
     1948      <div id="rfc.figure.u.32"></div><pre class="inline"><span id="rfc.iref.g.32"></span><span id="rfc.iref.g.33"></span>  <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a>  = #( <a href="#header.accept-encoding" class="smpl">codings</a> [ <a href="#quality.values" class="smpl">weight</a> ] )
    19481949  <a href="#header.accept-encoding" class="smpl">codings</a>          = <a href="#content.codings" class="smpl">content-coding</a> / "identity" / "*"
    19491950</pre><p id="rfc.section.6.3.4.p.3">Each codings value <em class="bcp14">MAY</em> be given an associated quality value which represents the preference for that encoding, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>.
    19501951      </p>
    19511952      <p id="rfc.section.6.3.4.p.4">For example,</p>
    1952       <div id="rfc.figure.u.32"></div><pre class="text">  Accept-Encoding: compress, gzip
     1953      <div id="rfc.figure.u.33"></div><pre class="text">  Accept-Encoding: compress, gzip
    19531954  Accept-Encoding:
    19541955  Accept-Encoding: *
     
    19851986         in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section&nbsp;3.1.3.1</a>.
    19861987      </p>
    1987       <div id="rfc.figure.u.33"></div><pre class="inline"><span id="rfc.iref.g.34"></span><span id="rfc.iref.g.35"></span>  <a href="#header.accept-language" class="smpl">Accept-Language</a> = 1#( <a href="#header.accept-language" class="smpl">language-range</a> [ <a href="#quality.values" class="smpl">weight</a> ] )
     1988      <div id="rfc.figure.u.34"></div><pre class="inline"><span id="rfc.iref.g.34"></span><span id="rfc.iref.g.35"></span>  <a href="#header.accept-language" class="smpl">Accept-Language</a> = 1#( <a href="#header.accept-language" class="smpl">language-range</a> [ <a href="#quality.values" class="smpl">weight</a> ] )
    19881989  <a href="#header.accept-language" class="smpl">language-range</a>  =
    19891990            &lt;language-range, defined in <a href="#RFC4647" id="rfc.xref.RFC4647.1"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-2.1">Section 2.1</a>&gt;
     
    19911992         languages specified by that range, as defined in <a href="#quality.values" title="Quality Values">Section&nbsp;6.3.1</a>. For example,
    19921993      </p>
    1993       <div id="rfc.figure.u.34"></div><pre class="text">  Accept-Language: da, en-gb;q=0.8, en;q=0.7
     1994      <div id="rfc.figure.u.35"></div><pre class="text">  Accept-Language: da, en-gb;q=0.8, en;q=0.7
    19941995</pre><p id="rfc.section.6.3.5.p.5">would mean: "I prefer Danish, but will accept British English and other types of English". (See also <a href="http://tools.ietf.org/html/rfc4647#section-2.3">Section 2.3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.2"><cite title="Matching of Language Tags">[RFC4647]</cite></a>)
    19951996      </p>
     
    20672068      <p id="rfc.section.6.5.1.p.1">The "From" header field, if given, <em class="bcp14">SHOULD</em> contain an Internet e-mail address for the human user who controls the requesting user agent. The address <em class="bcp14">SHOULD</em> be machine-usable, as defined by "mailbox" in <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.1"><cite title="Internet Message Format">[RFC5322]</cite></a>:
    20682069      </p>
    2069       <div id="rfc.figure.u.35"></div><pre class="inline"><span id="rfc.iref.g.36"></span>  <a href="#header.from" class="smpl">From</a>    = <a href="#header.from" class="smpl">mailbox</a>
     2070      <div id="rfc.figure.u.36"></div><pre class="inline"><span id="rfc.iref.g.36"></span>  <a href="#header.from" class="smpl">From</a>    = <a href="#header.from" class="smpl">mailbox</a>
    20702071 
    20712072  <a href="#header.from" class="smpl">mailbox</a> = &lt;mailbox, defined in <a href="#RFC5322" id="rfc.xref.RFC5322.2"><cite title="Internet Message Format">[RFC5322]</cite></a>, <a href="http://tools.ietf.org/html/rfc5322#section-3.4">Section 3.4</a>&gt;
    20722073</pre><p id="rfc.section.6.5.1.p.3">An example is:</p>
    2073       <div id="rfc.figure.u.36"></div><pre class="text">  From: webmaster@example.org
     2074      <div id="rfc.figure.u.37"></div><pre class="text">  From: webmaster@example.org
    20742075</pre><p id="rfc.section.6.5.1.p.5">This header field <em class="bcp14">MAY</em> be used for logging purposes and as a means for identifying the source of invalid or unwanted requests. It <em class="bcp14">SHOULD NOT</em> be used as an insecure form of access protection. The interpretation of this field is that the request is being performed
    20752076         on behalf of the person given, who accepts responsibility for the method performed. In particular, robot agents <em class="bcp14">SHOULD</em> include this header field so that the person responsible for running the robot can be contacted if problems occur on the receiving
     
    20962097         non-HTTP URIs (e.g., FTP).
    20972098      </p>
    2098       <div id="rfc.figure.u.37"></div><pre class="inline"><span id="rfc.iref.g.37"></span>  <a href="#header.referer" class="smpl">Referer</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a>
     2099      <div id="rfc.figure.u.38"></div><pre class="inline"><span id="rfc.iref.g.37"></span>  <a href="#header.referer" class="smpl">Referer</a> = <a href="#imported.abnf" class="smpl">absolute-URI</a> / <a href="#imported.abnf" class="smpl">partial-URI</a>
    20992100</pre><p id="rfc.section.6.5.2.p.5">Example:</p>
    2100       <div id="rfc.figure.u.38"></div><pre class="text">  Referer: http://www.example.org/hypertext/Overview.html
     2101      <div id="rfc.figure.u.39"></div><pre class="text">  Referer: http://www.example.org/hypertext/Overview.html
    21012102</pre><p id="rfc.section.6.5.2.p.7">If the field value is a relative URI, it <em class="bcp14">SHOULD</em> be interpreted relative to the effective request URI. The URI <em class="bcp14">MUST NOT</em> include a fragment. See <a href="#encoding.sensitive.information.in.uris" title="Encoding Sensitive Information in URIs">Section&nbsp;10.2</a> for security considerations.
    21022103      </p>
     
    21192120         doing so makes the field value more difficult to parse.
    21202121      </p>
    2121       <div id="rfc.figure.u.39"></div><pre class="inline"><span id="rfc.iref.g.38"></span>  <a href="#header.user-agent" class="smpl">User-Agent</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) )
     2122      <div id="rfc.figure.u.40"></div><pre class="inline"><span id="rfc.iref.g.38"></span>  <a href="#header.user-agent" class="smpl">User-Agent</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) )
    21222123</pre><p id="rfc.section.6.5.3.p.7">Example:</p>
    2123       <div id="rfc.figure.u.40"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
     2124      <div id="rfc.figure.u.41"></div><pre class="text">  User-Agent: CERN-LineMode/2.15 libwww/2.17b3
    21242125</pre><h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a id="status.codes" href="#status.codes">Response Status Codes</a></h1>
    21252126      <p id="rfc.section.7.p.1">The status-code element is a 3-digit integer code giving the result of the attempt to understand and satisfy the request.</p>
     
    27112712      <p id="rfc.section.7.5.15.p.1">The request can not be completed without a prior protocol upgrade. This response <em class="bcp14">MUST</em> include an <a href="p1-messaging.html#header.upgrade" class="smpl">Upgrade</a> header field (<a href="p1-messaging.html#header.upgrade" title="Upgrade">Section 6.3</a> of <a href="#Part1" id="rfc.xref.Part1.25"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>) specifying the required protocols.
    27122713      </p>
    2713       <div id="rfc.figure.u.41"></div>
     2714      <div id="rfc.figure.u.42"></div>
    27142715      <p>Example:</p>  <pre class="text">HTTP/1.1 426 Upgrade Required
    27152716Upgrade: HTTP/3.0
     
    28092810         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>:
    28102811      </p>
    2811       <div id="rfc.figure.u.42"></div><pre class="text">Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
     2812      <div id="rfc.figure.u.43"></div><pre class="text">Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 1123
    28122813</pre><p id="rfc.section.8.1.1.1.p.3">The other formats are described here only for compatibility with obsolete implementations.</p>
    2813       <div id="rfc.figure.u.43"></div><pre class="text">Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format
     2814      <div id="rfc.figure.u.44"></div><pre class="text">Sunday, 06-Nov-94 08:49:37 GMT ; obsolete RFC 850 format
    28142815Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format
    28152816</pre><p id="rfc.section.8.1.1.1.p.5">HTTP/1.1 clients and servers that parse a date value <em class="bcp14">MUST</em> accept all three formats (for compatibility with HTTP/1.0), though they <em class="bcp14">MUST</em> only generate the RFC 1123 format for representing HTTP-date values in header fields.
     
    28192820         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.
    28202821      </p>
    2821       <div id="rfc.figure.u.44"></div><pre class="inline"><span id="rfc.iref.g.39"></span>  <a href="#http.date" class="smpl">HTTP-date</a>    = <a href="#preferred.date.format" class="smpl">rfc1123-date</a> / <a href="#obsolete.date.formats" class="smpl">obs-date</a>
     2822      <div id="rfc.figure.u.45"></div><pre class="inline"><span id="rfc.iref.g.39"></span>  <a href="#http.date" class="smpl">HTTP-date</a>    = <a href="#preferred.date.format" class="smpl">rfc1123-date</a> / <a href="#obsolete.date.formats" class="smpl">obs-date</a>
    28222823</pre><div id="preferred.date.format">
    28232824         <p id="rfc.section.8.1.1.1.p.8">                    Preferred format:</p>
    28242825      </div>
    2825       <div id="rfc.figure.u.45"></div><pre class="inline"><span id="rfc.iref.g.40"></span><span id="rfc.iref.g.41"></span><span id="rfc.iref.g.42"></span><span id="rfc.iref.g.43"></span><span id="rfc.iref.g.44"></span><span id="rfc.iref.g.45"></span><span id="rfc.iref.g.46"></span><span id="rfc.iref.g.47"></span><span id="rfc.iref.g.48"></span><span id="rfc.iref.g.49"></span><span id="rfc.iref.g.50"></span><span id="rfc.iref.g.51"></span>  <a href="#preferred.date.format" class="smpl">rfc1123-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> "," <a href="#imported.abnf" class="smpl">SP</a> date1 <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
     2826      <div id="rfc.figure.u.46"></div><pre class="inline"><span id="rfc.iref.g.40"></span><span id="rfc.iref.g.41"></span><span id="rfc.iref.g.42"></span><span id="rfc.iref.g.43"></span><span id="rfc.iref.g.44"></span><span id="rfc.iref.g.45"></span><span id="rfc.iref.g.46"></span><span id="rfc.iref.g.47"></span><span id="rfc.iref.g.48"></span><span id="rfc.iref.g.49"></span><span id="rfc.iref.g.50"></span><span id="rfc.iref.g.51"></span>  <a href="#preferred.date.format" class="smpl">rfc1123-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> "," <a href="#imported.abnf" class="smpl">SP</a> date1 <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
    28262827  ; fixed length subset of the format defined in
    28272828  ; <a href="http://tools.ietf.org/html/rfc1123#section-5.2.14">Section 5.2.14</a> of <a href="#RFC1123" id="rfc.xref.RFC1123.2"><cite title="Requirements for Internet Hosts - Application and Support">[RFC1123]</cite></a>
     
    28662867         <p id="rfc.section.8.1.1.1.p.11">              Obsolete formats:</p>
    28672868      </div>
    2868       <div id="rfc.figure.u.46"></div><pre class="inline"><span id="rfc.iref.g.52"></span>  <a href="#obsolete.date.formats" class="smpl">obs-date</a>     = <a href="#obsolete.date.formats" class="smpl">rfc850-date</a> / <a href="#obsolete.date.formats" class="smpl">asctime-date</a>
    2869 </pre><div id="rfc.figure.u.47"></div><pre class="inline"><span id="rfc.iref.g.53"></span>  <a href="#obsolete.date.formats" class="smpl">rfc850-date</a>  = <a href="#obsolete.date.formats" class="smpl">day-name-l</a> "," <a href="#imported.abnf" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date2</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
     2869      <div id="rfc.figure.u.47"></div><pre class="inline"><span id="rfc.iref.g.52"></span>  <a href="#obsolete.date.formats" class="smpl">obs-date</a>     = <a href="#obsolete.date.formats" class="smpl">rfc850-date</a> / <a href="#obsolete.date.formats" class="smpl">asctime-date</a>
     2870</pre><div id="rfc.figure.u.48"></div><pre class="inline"><span id="rfc.iref.g.53"></span>  <a href="#obsolete.date.formats" class="smpl">rfc850-date</a>  = <a href="#obsolete.date.formats" class="smpl">day-name-l</a> "," <a href="#imported.abnf" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date2</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">GMT</a>
    28702871  <a href="#obsolete.date.formats" class="smpl">date2</a>        = <a href="#preferred.date.format" class="smpl">day</a> "-" <a href="#preferred.date.format" class="smpl">month</a> "-" 2<a href="#imported.abnf" class="smpl">DIGIT</a>
    28712872                 ; day-month-year (e.g., 02-Jun-82)
     
    28782879         / %x53.61.74.75.72.64.61.79 ; "Saturday", case-sensitive
    28792880         / %x53.75.6E.64.61.79 ; "Sunday", case-sensitive
    2880 </pre><div id="rfc.figure.u.48"></div><pre class="inline"><span id="rfc.iref.g.54"></span>  <a href="#obsolete.date.formats" class="smpl">asctime-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date3</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">year</a>
     2881</pre><div id="rfc.figure.u.49"></div><pre class="inline"><span id="rfc.iref.g.54"></span>  <a href="#obsolete.date.formats" class="smpl">asctime-date</a> = <a href="#preferred.date.format" class="smpl">day-name</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#obsolete.date.formats" class="smpl">date3</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">time-of-day</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#preferred.date.format" class="smpl">year</a>
    28812882  <a href="#obsolete.date.formats" class="smpl">date3</a>        = <a href="#preferred.date.format" class="smpl">month</a> <a href="#imported.abnf" class="smpl">SP</a> ( 2<a href="#imported.abnf" class="smpl">DIGIT</a> / ( <a href="#imported.abnf" class="smpl">SP</a> 1<a href="#imported.abnf" class="smpl">DIGIT</a> ))
    28822883                 ; month day (e.g., Jun  2)
     
    28962897         Origination Date Field (orig-date) defined in <a href="http://tools.ietf.org/html/rfc5322#section-3.6.1">Section 3.6.1</a> of <a href="#RFC5322" id="rfc.xref.RFC5322.4"><cite title="Internet Message Format">[RFC5322]</cite></a>. The field value is an HTTP-date, as defined in <a href="#http.date" title="Date/Time Formats">Section&nbsp;8.1.1.1</a>; it <em class="bcp14">MUST</em> be sent in rfc1123-date format.
    28972898      </p>
    2898       <div id="rfc.figure.u.49"></div><pre class="inline"><span id="rfc.iref.g.55"></span>  <a href="#header.date" class="smpl">Date</a> = <a href="#http.date" class="smpl">HTTP-date</a>
     2899      <div id="rfc.figure.u.50"></div><pre class="inline"><span id="rfc.iref.g.55"></span>  <a href="#header.date" class="smpl">Date</a> = <a href="#http.date" class="smpl">HTTP-date</a>
    28992900</pre><p id="rfc.section.8.1.1.2.p.3">An example is</p>
    2900       <div id="rfc.figure.u.50"></div><pre class="text">  Date: Tue, 15 Nov 1994 08:12:31 GMT
     2901      <div id="rfc.figure.u.51"></div><pre class="text">  Date: Tue, 15 Nov 1994 08:12:31 GMT
    29012902</pre><p id="rfc.section.8.1.1.2.p.5">Origin servers <em class="bcp14">MUST</em> include a Date header field in all responses, except in these cases:
    29022903      </p>
     
    29242925      <p id="rfc.section.8.1.2.p.1">The "Location" header field <em class="bcp14">MAY</em> be sent in responses to refer to a specific resource in accordance with the semantics of the status code.
    29252926      </p>
    2926       <div id="rfc.figure.u.51"></div><pre class="inline"><span id="rfc.iref.g.56"></span>  <a href="#header.location" class="smpl">Location</a> = <a href="#imported.abnf" class="smpl">URI-reference</a>
     2927      <div id="rfc.figure.u.52"></div><pre class="inline"><span id="rfc.iref.g.56"></span>  <a href="#header.location" class="smpl">Location</a> = <a href="#imported.abnf" class="smpl">URI-reference</a>
    29272928</pre><p id="rfc.section.8.1.2.p.3">For <a href="#status.201" class="smpl">201 (Created)</a> responses, the Location is the URI of the new resource which was created by the request. For <a href="#status.3xx" class="smpl">3xx (Redirection)</a> responses, the location <em class="bcp14">SHOULD</em> indicate the server's preferred URI for automatic redirection to the resource.
    29282929      </p>
     
    29302931         then the original URI's fragment identifier is added to the final value.
    29312932      </p>
    2932       <div id="rfc.figure.u.52"></div>
     2933      <div id="rfc.figure.u.53"></div>
    29332934      <p>For example, the original URI "http://www.example.org/~tim", combined with a field value given as:</p>  <pre class="text">  Location: /pub/WWW/People.html#tim
    29342935</pre>  <p>would result in a final value of "http://www.example.org/pub/WWW/People.html#tim"</p>
    2935       <div id="rfc.figure.u.53"></div>
     2936      <div id="rfc.figure.u.54"></div>
    29362937      <p>An original URI "http://www.example.org/index.html#larry", combined with a field value given as:</p>  <pre class="text">  Location: http://www.example.net/index.html
    29372938</pre>  <p>would result in a final value of "http://www.example.net/index.html#larry", preserving the original fragment identifier.</p>
     
    29562957      </p>
    29572958      <p id="rfc.section.8.1.3.p.2">The value of this field can be either an HTTP-date or an integer number of seconds (in decimal) after the time of the response.</p>
    2958       <div id="rfc.figure.u.54"></div><pre class="inline"><span id="rfc.iref.g.57"></span>  <a href="#header.retry-after" class="smpl">Retry-After</a> = <a href="#http.date" class="smpl">HTTP-date</a> / <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>
     2959      <div id="rfc.figure.u.55"></div><pre class="inline"><span id="rfc.iref.g.57"></span>  <a href="#header.retry-after" class="smpl">Retry-After</a> = <a href="#http.date" class="smpl">HTTP-date</a> / <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>
    29592960</pre><div id="rule.delta-seconds">
    29602961         <p id="rfc.section.8.1.3.p.4">  Time spans are non-negative decimal integers, representing time in seconds.</p>
    29612962      </div>
    2962       <div id="rfc.figure.u.55"></div><pre class="inline"><span id="rfc.iref.g.58"></span>  <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>  = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
     2963      <div id="rfc.figure.u.56"></div><pre class="inline"><span id="rfc.iref.g.58"></span>  <a href="#rule.delta-seconds" class="smpl">delta-seconds</a>  = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
    29632964</pre><p id="rfc.section.8.1.3.p.6">Two examples of its use are</p>
    2964       <div id="rfc.figure.u.56"></div><pre class="text">  Retry-After: Fri, 31 Dec 1999 23:59:59 GMT
     2965      <div id="rfc.figure.u.57"></div><pre class="text">  Retry-After: Fri, 31 Dec 1999 23:59:59 GMT
    29652966  Retry-After: 120
    29662967</pre><p id="rfc.section.8.1.3.p.8">In the latter example, the delay is 2 minutes.</p>
     
    30053006         the representation.
    30063007      </p>
    3007       <div id="rfc.figure.u.57"></div><pre class="inline"><span id="rfc.iref.g.59"></span>  <a href="#header.vary" class="smpl">Vary</a> = "*" / 1#<a href="#imported.abnf" class="smpl">field-name</a>
     3008      <div id="rfc.figure.u.58"></div><pre class="inline"><span id="rfc.iref.g.59"></span>  <a href="#header.vary" class="smpl">Vary</a> = "*" / 1#<a href="#imported.abnf" class="smpl">field-name</a>
    30083009</pre><p id="rfc.section.8.2.1.p.5">The set of header fields named by the Vary field value is known as the selecting header fields.</p>
    30093010      <p id="rfc.section.8.2.1.p.6">A server <em class="bcp14">SHOULD</em> include a Vary header field with any cacheable response that is subject to proactive negotiation. Doing so allows a cache
     
    30743075         is strictly to inform the recipient of valid request methods associated with the resource.
    30753076      </p>
    3076       <div id="rfc.figure.u.58"></div><pre class="inline"><span id="rfc.iref.g.60"></span>  <a href="#header.allow" class="smpl">Allow</a> = #<a href="#method.overview" class="smpl">method</a>
     3077      <div id="rfc.figure.u.59"></div><pre class="inline"><span id="rfc.iref.g.60"></span>  <a href="#header.allow" class="smpl">Allow</a> = #<a href="#method.overview" class="smpl">method</a>
    30773078</pre><p id="rfc.section.8.4.1.p.3">Example of use:</p>
    3078       <div id="rfc.figure.u.59"></div><pre class="text">  Allow: GET, HEAD, PUT
     3079      <div id="rfc.figure.u.60"></div><pre class="text">  Allow: GET, HEAD, PUT
    30793080</pre><p id="rfc.section.8.4.1.p.5">The actual set of allowed methods is defined by the origin server at the time of each request.</p>
    30803081      <p id="rfc.section.8.4.1.p.6">A proxy <em class="bcp14">MUST NOT</em> modify the Allow header field — it does not need to understand all the methods specified in order to handle them according
     
    30873088         identifying the application.
    30883089      </p>
    3089       <div id="rfc.figure.u.60"></div><pre class="inline"><span id="rfc.iref.g.61"></span>  <a href="#header.server" class="smpl">Server</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) )
     3090      <div id="rfc.figure.u.61"></div><pre class="inline"><span id="rfc.iref.g.61"></span>  <a href="#header.server" class="smpl">Server</a> = <a href="#product.tokens" class="smpl">product</a> *( <a href="#imported.abnf" class="smpl">RWS</a> ( <a href="#product.tokens" class="smpl">product</a> / <a href="#imported.abnf" class="smpl">comment</a> ) )
    30903091</pre><p id="rfc.section.8.4.2.p.4">Example:</p>
    3091       <div id="rfc.figure.u.61"></div><pre class="text">  Server: CERN/3.0 libwww/2.17
     3092      <div id="rfc.figure.u.62"></div><pre class="text">  Server: CERN/3.0 libwww/2.17
    30923093</pre><p id="rfc.section.8.4.2.p.6">If the response is being forwarded through a proxy, the proxy application <em class="bcp14">MUST NOT</em> modify the <a href="#header.server" class="smpl">Server</a> header field. Instead, it <em class="bcp14">MUST</em> include a <a href="p1-messaging.html#header.via" class="smpl">Via</a> field (as described in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.29"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>).
    30933094      </p>
     
    34773478         these:
    34783479      </p>
    3479       <div id="rfc.figure.u.62"></div><pre class="text">  Example-URI-Field: "http://example.com/a.html,foo",
     3480      <div id="rfc.figure.u.63"></div><pre class="text">  Example-URI-Field: "http://example.com/a.html,foo",
    34803481                     "http://without-a-comma.example.com/"
    34813482  Example-Date-Field: "Sat, 04 May 1996", "Wed, 14 Sep 2005"
     
    34853486      <p id="rfc.section.9.3.1.p.8">Many header fields use a format including (case-insensitively) named parameters (for instance, <a href="#header.content-type" class="smpl">Content-Type</a>, defined in <a href="#header.content-type" id="rfc.xref.header.content-type.4" title="Content-Type">Section&nbsp;3.1.1.5</a>). Allowing both unquoted (token) and quoted (quoted-string) syntax for the parameter value enables recipients to use existing
    34863487         parser components. When allowing both forms, the meaning of a parameter value ought to be independent of the syntax used for
    3487          it (for an example, see the notes on parameter handling for media types in <a href="#media.types" title="Media Types">Section&nbsp;3.1.1.1</a>).
     3488         it (for an example, see the notes on parameter handling for media types in <a href="#media.type" title="Media Type">Section&nbsp;3.1.1.1</a>).
    34883489      </p>
    34893490      <p id="rfc.section.9.3.1.p.9">Authors of specifications defining new header fields are advised to consider documenting: </p>
     
    38243825      <h2 id="rfc.references.1"><a href="#rfc.section.12.1" id="rfc.section.12.1">12.1</a> Normative References
    38253826      </h2>
    3826       <table>                             
     3827      <table>                               
    38273828         <tr>
    38283829            <td class="reference"><b id="Part1">[Part1]</b></td>
     
    39003901            </td>
    39013902         </tr>
     3903         <tr>
     3904            <td class="reference"><b id="RFC6365">[RFC6365]</b></td>
     3905            <td class="top">Hoffman, P. and J. Klensin, “<a href="http://tools.ietf.org/html/rfc6365">Terminology Used in Internationalization in the IETF</a>”, BCP&nbsp;166, RFC&nbsp;6365, September&nbsp;2011.
     3906            </td>
     3907         </tr>
    39023908      </table>
    39033909      <h2 id="rfc.references.2"><a href="#rfc.section.12.2" id="rfc.section.12.2">12.2</a> Informative References
    39043910      </h2>
    3905       <table>                                           
     3911      <table>                                         
    39063912         <tr>
    39073913            <td class="reference"><b id="REST">[REST]</b></td>
     
    39353941         </tr>
    39363942         <tr>
    3937             <td class="reference"><b id="RFC2277">[RFC2277]</b></td>
    3938             <td class="top"><a href="mailto:Harald.T.Alvestrand@uninett.no" title="UNINETT">Alvestrand, H.</a>, “<a href="http://tools.ietf.org/html/rfc2277">IETF Policy on Character Sets and Languages</a>”, BCP&nbsp;18, RFC&nbsp;2277, January&nbsp;1998.
    3939             </td>
    3940          </tr>
    3941          <tr>
    39423943            <td class="reference"><b id="RFC2295">[RFC2295]</b></td>
    39433944            <td class="top"><a href="mailto:koen@win.tue.nl" title="Technische Universiteit Eindhoven">Holtman, K.</a> and <a href="mailto:mutz@hpl.hp.com" title="Hewlett-Packard Company">A. Mutz</a>, “<a href="http://tools.ietf.org/html/rfc2295">Transparent Content Negotiation in HTTP</a>”, RFC&nbsp;2295, March&nbsp;1998.
     
    39653966         </tr>
    39663967         <tr>
    3967             <td class="reference"><b id="RFC3629">[RFC3629]</b></td>
    3968             <td class="top"><a href="mailto:fyergeau@alis.com" title="Alis Technologies">Yergeau, F.</a>, “<a href="http://tools.ietf.org/html/rfc3629">UTF-8, a transformation format of ISO 10646</a>”, STD&nbsp;63, RFC&nbsp;3629, November&nbsp;2003.
     3968            <td class="reference"><b id="RFC2978">[RFC2978]</b></td>
     3969            <td class="top">Freed, N. and J. Postel, “<a href="http://tools.ietf.org/html/rfc2978">IANA Charset Registration Procedures</a>”, BCP&nbsp;19, RFC&nbsp;2978, October&nbsp;2000.
    39693970            </td>
    39703971         </tr>
     
    40404041         MIME environments.
    40414042      </p>
    4042       <div id="rfc.figure.u.63"></div><pre class="inline"><span id="rfc.iref.g.62"></span>  <a href="#mime-version" class="smpl">MIME-Version</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a> "." 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
     4043      <div id="rfc.figure.u.64"></div><pre class="inline"><span id="rfc.iref.g.62"></span>  <a href="#mime-version" class="smpl">MIME-Version</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a> "." 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
    40434044</pre><p id="rfc.section.A.1.p.3">MIME version "1.0" is the default for use in HTTP/1.1. However, HTTP/1.1 message parsing and semantics are defined by this
    40444045         document and not the MIME specification.
     
    40504051      </p>
    40514052      <p id="rfc.section.A.2.p.2">Where it is possible, a proxy or gateway from HTTP to a strict MIME environment <em class="bcp14">SHOULD</em> translate all line breaks within the text media types described in <a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section&nbsp;3.1.1.3</a> of this document to the RFC 2049 canonical form of CRLF. Note, however, that this might be complicated by the presence of
    4052          a <a href="#header.content-encoding" class="smpl">Content-Encoding</a> and by the fact that HTTP allows the use of some character encodings which do not use octets 13 and 10 to represent CR and
    4053          LF, respectively, as is the case for some multi-byte character encodings.
     4053         a <a href="#header.content-encoding" class="smpl">Content-Encoding</a> and by the fact that HTTP allows the use of some charsets which do not use octets 13 and 10 to represent CR and LF, respectively.
    40544054      </p>
    40554055      <p id="rfc.section.A.2.p.3">Conversion will break any cryptographic checksums applied to the original content unless the original content is already in
     
    41284128         in <a href="p1-messaging.html#header.via" title="Via">Section 5.7</a> of <a href="#Part1" id="rfc.xref.Part1.44"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>. (<a href="#header.server" id="rfc.xref.header.server.4" title="Server">Section&nbsp;8.4.2</a>)
    41294129      </p>
    4130       <p id="rfc.section.C.p.17">Clarify contexts that charset is used in. (<a href="#character.sets" title="Character Encodings (charset)">Section&nbsp;3.1.1.2</a>)
    4131       </p>
    4132       <p id="rfc.section.C.p.18">Remove the default character encoding of "ISO-8859-1" for text media types; the default now is whatever the media type definition
    4133          says. (<a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section&nbsp;3.1.1.3</a>)
     4130      <p id="rfc.section.C.p.17">Clarify contexts that charset is used in. (<a href="#charset" title="Charset">Section&nbsp;3.1.1.2</a>)
     4131      </p>
     4132      <p id="rfc.section.C.p.18">Remove the default charset of "ISO-8859-1" for text media types; the default now is whatever the media type definition says.
     4133         (<a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section&nbsp;3.1.1.3</a>)
    41344134      </p>
    41354135      <p id="rfc.section.C.p.19">Registration of Content Codings now requires IETF Review (<a href="#content.coding.registry" title="Content Coding Registry">Section&nbsp;9.4</a>)
     
    41534153      <p id="rfc.section.D.p.2">The rules below are defined in <a href="#Part1" id="rfc.xref.Part1.45"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>:
    41544154      </p>
    4155       <div id="rfc.figure.u.64"></div><pre class="inline">  <a href="#imported.abnf" class="smpl">BWS</a>           = &lt;BWS, defined in <a href="#Part1" id="rfc.xref.Part1.46"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>, <a href="p1-messaging.html#whitespace" title="Whitespace">Section 3.2.1</a>&gt;
     4155      <div id="rfc.figure.u.65"></div><pre class="inline">  <a href="#imported.abnf" class="smpl">BWS</a>           = &lt;BWS, defined in <a href="#Part1" id="rfc.xref.Part1.46"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>, <a href="p1-messaging.html#whitespace" title="Whitespace">Section 3.2.1</a>&gt;
    41564156  <a href="#imported.abnf" class="smpl">OWS</a>           = &lt;OWS, defined in <a href="#Part1" id="rfc.xref.Part1.47"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>, <a href="p1-messaging.html#whitespace" title="Whitespace">Section 3.2.1</a>&gt;
    41574157  <a href="#imported.abnf" class="smpl">RWS</a>           = &lt;RWS, defined in <a href="#Part1" id="rfc.xref.Part1.48"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>, <a href="p1-messaging.html#whitespace" title="Whitespace">Section 3.2.1</a>&gt;
     
    41654165  <a href="#imported.abnf" class="smpl">word</a>          = &lt;word, defined in <a href="#Part1" id="rfc.xref.Part1.56"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[Part1]</cite></a>, <a href="p1-messaging.html#field.components" title="Field value components">Section 3.2.4</a>&gt;
    41664166</pre><h1 id="rfc.section.E"><a href="#rfc.section.E">E.</a>&nbsp;<a id="collected.abnf" href="#collected.abnf">Collected ABNF</a></h1>
    4167       <div id="rfc.figure.u.65"></div> <pre class="inline"><a href="#header.accept" class="smpl">Accept</a> = [ ( "," / ( media-range [ accept-params ] ) ) *( OWS "," [
     4167      <div id="rfc.figure.u.66"></div> <pre class="inline"><a href="#header.accept" class="smpl">Accept</a> = [ ( "," / ( media-range [ accept-params ] ) ) *( OWS "," [
    41684168 OWS ( media-range [ accept-params ] ) ] ) ]
    41694169<a href="#header.accept-charset" class="smpl">Accept-Charset</a> = *( "," OWS ) ( ( charset / "*" ) [ weight ] ) *( OWS
     
    42194219<a href="#rule.parameter" class="smpl">attribute</a> = token
    42204220
    4221 <a href="#rule.charset" class="smpl">charset</a> = token
     4221<a href="#charset" class="smpl">charset</a> = token
    42224222<a href="#header.accept-encoding" class="smpl">codings</a> = content-coding / "identity" / "*"
    42234223<a href="#imported.abnf" class="smpl">comment</a> = &lt;comment, defined in [Part1], Section 3.2.4&gt;
     
    42604260<a href="#header.accept" class="smpl">media-range</a> = ( "*/*" / ( type "/*" ) / ( type "/" subtype ) ) *( OWS
    42614261 ";" OWS parameter )
    4262 <a href="#media.types" class="smpl">media-type</a> = type "/" subtype *( OWS ";" OWS parameter )
     4262<a href="#media.type" class="smpl">media-type</a> = type "/" subtype *( OWS ";" OWS parameter )
    42634263<a href="#method.overview" class="smpl">method</a> = token
    42644264<a href="#preferred.date.format" class="smpl">minute</a> = 2DIGIT
     
    42904290
    42914291<a href="#preferred.date.format" class="smpl">second</a> = 2DIGIT
    4292 <a href="#media.types" class="smpl">subtype</a> = token
     4292<a href="#media.type" class="smpl">subtype</a> = token
    42934293
    42944294<a href="#preferred.date.format" class="smpl">time-of-day</a> = hour ":" minute ":" second
    42954295<a href="#imported.abnf" class="smpl">token</a> = &lt;token, defined in [Part1], Section 3.2.4&gt;
    4296 <a href="#media.types" class="smpl">type</a> = token
     4296<a href="#media.type" class="smpl">type</a> = token
    42974297
    42984298<a href="#rule.parameter" class="smpl">value</a> = word
     
    46184618                  <li><em>RFC2076</em>&nbsp;&nbsp;<a href="#RFC2076"><b>12.2</b></a>, <a href="#rfc.xref.RFC2076.1">B</a></li>
    46194619                  <li><em>RFC2119</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2119.1">1.1</a>, <a href="#RFC2119"><b>12.1</b></a></li>
    4620                   <li><em>RFC2277</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2277.1">3.1.1.2</a>, <a href="#RFC2277"><b>12.2</b></a></li>
    46214620                  <li><em>RFC2295</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2295.1">3.4</a>, <a href="#RFC2295"><b>12.2</b></a></li>
    46224621                  <li><em>RFC2388</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2388.1">3.1.1.4</a>, <a href="#RFC2388"><b>12.2</b></a></li>
     
    46344633                     </ul>
    46354634                  </li>
    4636                   <li><em>RFC3629</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3629.1">3.1.1.2</a>, <a href="#RFC3629"><b>12.2</b></a></li>
     4635                  <li><em>RFC2978</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2978.1">3.1.1.2</a>, <a href="#RFC2978"><b>12.2</b></a></li>
    46374636                  <li><em>RFC3864</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3864.1">9.3</a>, <a href="#rfc.xref.RFC3864.2">9.3.1</a>, <a href="#RFC3864"><b>12.2</b></a><ul>
    46384637                        <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3864.2">9.3.1</a></li>
     
    46744673                  <li><em>RFC6151</em>&nbsp;&nbsp;<a href="#RFC6151"><b>12.2</b></a>, <a href="#rfc.xref.RFC6151.1">C</a></li>
    46754674                  <li><em>RFC6266</em>&nbsp;&nbsp;<a href="#RFC6266"><b>12.2</b></a>, <a href="#rfc.xref.RFC6266.1">B</a>, <a href="#rfc.xref.RFC6266.2">C</a></li>
     4675                  <li><em>RFC6365</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC6365.1">1.2</a>, <a href="#rfc.xref.RFC6365.2">3.1.1.2</a>, <a href="#RFC6365"><b>12.1</b></a></li>
    46764676               </ul>
    46774677            </li>
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