source: draft-ietf-httpbis/latest/p5-range.html @ 2734

Last change on this file since 2734 was 2734, checked in by julian.reschke@…, 5 years ago

update XSLTs, switch to Saxon 9.6 HE in Makefile, regen specs

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487       content: "HTTP/1.1 Range Requests";
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511</style><link rel="Contents" href="#rfc.toc">
512      <link rel="Author" href="#rfc.authors">
513      <link rel="Copyright" href="#rfc.copyrightnotice">
514      <link rel="Index" href="#rfc.index">
515      <link rel="Chapter" title="1 Introduction" href="#rfc.section.1">
516      <link rel="Chapter" title="2 Range Units" href="#rfc.section.2">
517      <link rel="Chapter" title="3 Range Requests" href="#rfc.section.3">
518      <link rel="Chapter" title="4 Responses to a Range Request" href="#rfc.section.4">
519      <link rel="Chapter" title="5 IANA Considerations" href="#rfc.section.5">
520      <link rel="Chapter" title="6 Security Considerations" href="#rfc.section.6">
521      <link rel="Chapter" title="7 Acknowledgments" href="#rfc.section.7">
522      <link rel="Chapter" href="#rfc.section.8" title="8 References">
523      <link rel="Appendix" title="A Internet Media Type multipart/byteranges" href="#rfc.section.A">
524      <link rel="Appendix" title="B Changes from RFC 2616" href="#rfc.section.B">
525      <link rel="Appendix" title="C Imported ABNF" href="#rfc.section.C">
526      <link rel="Appendix" title="D Collected ABNF" href="#rfc.section.D">
527      <link rel="Alternate" title="RFC7233" href="http://svn.tools.ietf.org/svn/wg/httpbis/specs/rfc7233.html">
528      <link href="p4-conditional.html" rel="prev">
529      <link href="p6-cache.html" rel="next">
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531      <meta name="keywords" content="Hypertext Transfer Protocol, HTTP, HTTP Range Requests">
532      <link rel="schema.dct" href="http://purl.org/dc/terms/">
533      <meta name="dct.creator" content="Fielding, R.">
534      <meta name="dct.creator" content="Lafon, Y.">
535      <meta name="dct.creator" content="Reschke, J. F.">
536      <meta name="dct.identifier" content="urn:ietf:id:draft-ietf-httpbis-p5-range-latest">
537      <meta name="dct.issued" scheme="ISO8601" content="2014-06">
538      <meta name="dct.replaces" content="urn:ietf:rfc:2616">
539      <meta name="dct.abstract" content="The Hypertext Transfer Protocol (HTTP) is a stateless application-level protocol for distributed, collaborative, hypertext information systems. This document defines range requests and the rules for constructing and combining responses to those requests.">
540      <meta name="description" content="The Hypertext Transfer Protocol (HTTP) is a stateless application-level protocol for distributed, collaborative, hypertext information systems. This document defines range requests and the rules for constructing and combining responses to those requests.">
541   </head>
542   <body onload="initFeedback();">
543      <table class="header" id="rfc.headerblock">
544         <tbody>
545            <tr>
546               <td class="left">HTTPbis Working Group</td>
547               <td class="right">R. Fielding, Editor</td>
548            </tr>
549            <tr>
550               <td class="left">Internet-Draft</td>
551               <td class="right">Adobe</td>
552            </tr>
553            <tr>
554               <td class="left">Obsoletes: <a href="https://tools.ietf.org/html/rfc2616">2616</a> (if approved)
555               </td>
556               <td class="right">Y. Lafon, Editor</td>
557            </tr>
558            <tr>
559               <td class="left">Intended status: Standards Track</td>
560               <td class="right">W3C</td>
561            </tr>
562            <tr>
563               <td class="left">Expires: December 2014</td>
564               <td class="right">J. Reschke, Editor</td>
565            </tr>
566            <tr>
567               <td class="left"></td>
568               <td class="right">greenbytes</td>
569            </tr>
570            <tr>
571               <td class="left"></td>
572               <td class="right">June 2014</td>
573            </tr>
574         </tbody>
575      </table>
576      <p class="title" id="rfc.title">Hypertext Transfer Protocol (HTTP/1.1): Range Requests<br><span class="filename">draft-ietf-httpbis-p5-range-latest</span></p>
577      <p style="color: green; text-align: center; font-size: 14pt; background-color: yellow;"><b>Note:</b> a later version of this document has been published as <a href="http://svn.tools.ietf.org/svn/wg/httpbis/specs/rfc7233.html">RFC7233</a>.
578         
579      </p>
580      <h1 id="rfc.abstract"><a href="#rfc.abstract">Abstract</a></h1>
581      <p>The Hypertext Transfer Protocol (HTTP) is a stateless application-level protocol for
582         distributed, collaborative, hypertext information systems. This document defines range
583         requests and the rules for constructing and combining responses to those requests.
584      </p>
585      <h1 id="rfc.note.1"><a href="#rfc.note.1">Editorial Note (To be removed by RFC Editor)</a></h1>
586      <p>Discussion of this draft takes place on the HTTPBIS working group mailing list (ietf-http-wg@w3.org),
587         which is archived at &lt;<a href="http://lists.w3.org/Archives/Public/ietf-http-wg/">http://lists.w3.org/Archives/Public/ietf-http-wg/</a>&gt;.
588      </p>
589      <p>The current issues list is at &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/report/3">http://tools.ietf.org/wg/httpbis/trac/report/3</a>&gt; and related documents (including fancy diffs) can be found at &lt;<a href="http://tools.ietf.org/wg/httpbis/">http://tools.ietf.org/wg/httpbis/</a>&gt;.
590      </p>
591      <p><em>This is a temporary document for the purpose of tracking the editorial changes made
592            during the AUTH48 (RFC publication) phase.</em>
593      </p>
594      <div id="rfc.status">
595         <h1><a href="#rfc.status">Status of This Memo</a></h1>
596         <p>This Internet-Draft is submitted in full conformance with the provisions of BCP 78
597            and BCP 79.
598         </p>
599         <p>Internet-Drafts are working documents of the Internet Engineering Task Force (IETF).
600            Note that other groups may also distribute working documents as Internet-Drafts. The
601            list of current Internet-Drafts is at <a href="http://datatracker.ietf.org/drafts/current/">http://datatracker.ietf.org/drafts/current/</a>.
602         </p>
603         <p>Internet-Drafts are draft documents valid for a maximum of six months and may be updated,
604            replaced, or obsoleted by other documents at any time. It is inappropriate to use
605            Internet-Drafts as reference material or to cite them other than as “work in progress”.
606         </p>
607         <p>This Internet-Draft will expire in December 2014.</p>
608      </div>
609      <div id="rfc.copyrightnotice">
610         <h1><a href="#rfc.copyrightnotice">Copyright Notice</a></h1>
611         <p>Copyright © 2014 IETF Trust and the persons identified as the document authors. All
612            rights reserved.
613         </p>
614         <p>This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating
615            to IETF Documents (<a href="http://trustee.ietf.org/license-info">http://trustee.ietf.org/license-info</a>) in effect on the date of publication of this document. Please review these documents
616            carefully, as they describe your rights and restrictions with respect to this document.
617            Code Components extracted from this document must include Simplified BSD License text
618            as described in Section 4.e of the Trust Legal Provisions and are provided without
619            warranty as described in the Simplified BSD License.
620         </p>
621         <p>This document may contain material from IETF Documents or IETF Contributions published
622            or made publicly available before November 10, 2008. The person(s) controlling the
623            copyright in some of this material may not have granted the IETF Trust the right to
624            allow modifications of such material outside the IETF Standards Process. Without obtaining
625            an adequate license from the person(s) controlling the copyright in such materials,
626            this document may not be modified outside the IETF Standards Process, and derivative
627            works of it may not be created outside the IETF Standards Process, except to format
628            it for publication as an RFC or to translate it into languages other than English.
629         </p>
630      </div>
631      <hr class="noprint">
632      <div id="rfc.toc">
633         <h1 class="np"><a href="#rfc.toc">Table of Contents</a></h1>
634         <ul class="toc">
635            <li><a href="#rfc.section.1">1.</a>&nbsp;&nbsp;&nbsp;<a href="#introduction">Introduction</a><ul>
636                  <li><a href="#rfc.section.1.1">1.1</a>&nbsp;&nbsp;&nbsp;<a href="#conformance">Conformance and Error Handling</a></li>
637                  <li><a href="#rfc.section.1.2">1.2</a>&nbsp;&nbsp;&nbsp;<a href="#notation">Syntax Notation</a></li>
638               </ul>
639            </li>
640            <li><a href="#rfc.section.2">2.</a>&nbsp;&nbsp;&nbsp;<a href="#range.units">Range Units</a><ul>
641                  <li><a href="#rfc.section.2.1">2.1</a>&nbsp;&nbsp;&nbsp;<a href="#byte.ranges">Byte Ranges</a></li>
642                  <li><a href="#rfc.section.2.2">2.2</a>&nbsp;&nbsp;&nbsp;<a href="#range.units.other">Other Range Units</a></li>
643                  <li><a href="#rfc.section.2.3">2.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.accept-ranges">Accept-Ranges</a></li>
644               </ul>
645            </li>
646            <li><a href="#rfc.section.3">3.</a>&nbsp;&nbsp;&nbsp;<a href="#range.requests">Range Requests</a><ul>
647                  <li><a href="#rfc.section.3.1">3.1</a>&nbsp;&nbsp;&nbsp;<a href="#header.range">Range</a></li>
648                  <li><a href="#rfc.section.3.2">3.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.if-range">If-Range</a></li>
649               </ul>
650            </li>
651            <li><a href="#rfc.section.4">4.</a>&nbsp;&nbsp;&nbsp;<a href="#range.response">Responses to a Range Request</a><ul>
652                  <li><a href="#rfc.section.4.1">4.1</a>&nbsp;&nbsp;&nbsp;<a href="#status.206">206 Partial Content</a></li>
653                  <li><a href="#rfc.section.4.2">4.2</a>&nbsp;&nbsp;&nbsp;<a href="#header.content-range">Content-Range</a></li>
654                  <li><a href="#rfc.section.4.3">4.3</a>&nbsp;&nbsp;&nbsp;<a href="#combining.byte.ranges">Combining Ranges</a></li>
655                  <li><a href="#rfc.section.4.4">4.4</a>&nbsp;&nbsp;&nbsp;<a href="#status.416">416 Range Not Satisfiable</a></li>
656               </ul>
657            </li>
658            <li><a href="#rfc.section.5">5.</a>&nbsp;&nbsp;&nbsp;<a href="#IANA.considerations">IANA Considerations</a><ul>
659                  <li><a href="#rfc.section.5.1">5.1</a>&nbsp;&nbsp;&nbsp;<a href="#range.unit.registry">Range Unit Registry</a><ul>
660                        <li><a href="#rfc.section.5.1.1">5.1.1</a>&nbsp;&nbsp;&nbsp;<a href="#range.unit.registry.procedure">Procedure</a></li>
661                        <li><a href="#rfc.section.5.1.2">5.1.2</a>&nbsp;&nbsp;&nbsp;<a href="#range.unit.registration">Registrations</a></li>
662                     </ul>
663                  </li>
664                  <li><a href="#rfc.section.5.2">5.2</a>&nbsp;&nbsp;&nbsp;<a href="#status.code.registration">Status Code Registration</a></li>
665                  <li><a href="#rfc.section.5.3">5.3</a>&nbsp;&nbsp;&nbsp;<a href="#header.field.registration">Header Field Registration</a></li>
666                  <li><a href="#rfc.section.5.4">5.4</a>&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.http">Internet Media Type Registration</a><ul>
667                        <li><a href="#rfc.section.5.4.1">5.4.1</a>&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.multipart.byteranges.reg">Internet Media Type multipart/byteranges</a></li>
668                     </ul>
669                  </li>
670               </ul>
671            </li>
672            <li><a href="#rfc.section.6">6.</a>&nbsp;&nbsp;&nbsp;<a href="#security.considerations">Security Considerations</a><ul>
673                  <li><a href="#rfc.section.6.1">6.1</a>&nbsp;&nbsp;&nbsp;<a href="#overlapping.ranges">Denial-of-Service Attacks Using Range</a></li>
674               </ul>
675            </li>
676            <li><a href="#rfc.section.7">7.</a>&nbsp;&nbsp;&nbsp;<a href="#acks">Acknowledgments</a></li>
677            <li><a href="#rfc.section.8">8.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references">References</a><ul>
678                  <li><a href="#rfc.section.8.1">8.1</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references.1">Normative References</a></li>
679                  <li><a href="#rfc.section.8.2">8.2</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references.2">Informative References</a></li>
680               </ul>
681            </li>
682            <li><a href="#rfc.section.A">A.</a>&nbsp;&nbsp;&nbsp;<a href="#internet.media.type.multipart.byteranges">Internet Media Type multipart/byteranges</a></li>
683            <li><a href="#rfc.section.B">B.</a>&nbsp;&nbsp;&nbsp;<a href="#changes.from.rfc.2616">Changes from RFC 2616</a></li>
684            <li><a href="#rfc.section.C">C.</a>&nbsp;&nbsp;&nbsp;<a href="#imported.abnf">Imported ABNF</a></li>
685            <li><a href="#rfc.section.D">D.</a>&nbsp;&nbsp;&nbsp;<a href="#collected.abnf">Collected ABNF</a></li>
686            <li><a href="#rfc.index">Index</a></li>
687            <li><a href="#rfc.authors">Authors' Addresses</a></li>
688         </ul>
689      </div>
690      <div id="introduction">
691         <h1 id="rfc.section.1" class="np"><a href="#rfc.section.1">1.</a>&nbsp;<a href="#introduction">Introduction</a></h1>
692         <div id="rfc.section.1.p.1">
693            <p>Hypertext Transfer Protocol (HTTP) clients often encounter interrupted data transfers
694               as a result of canceled requests or dropped connections. When a client has stored
695               a partial representation, it is desirable to request the remainder of that representation
696               in a subsequent request rather than transfer the entire representation. Likewise,
697               devices with limited local storage might benefit from being able to request only a
698               subset of a larger representation, such as a single page of a very large document,
699               or the dimensions of an embedded image.
700            </p>
701         </div>
702         <div id="rfc.section.1.p.2">
703            <p>This document defines HTTP/1.1 range requests, partial responses, and the multipart/byteranges
704               media type. Range requests are an <em class="bcp14">OPTIONAL</em> feature of HTTP, designed so that recipients not implementing this feature (or not
705               supporting it for the target resource) can respond as if it is a normal GET request
706               without impacting interoperability. Partial responses are indicated by a distinct
707               status code to not be mistaken for full responses by caches that might not implement
708               the feature.
709            </p>
710         </div>
711         <div id="rfc.section.1.p.3">
712            <p>Although the range request mechanism is designed to allow for extensible range types,
713               this specification only defines requests for byte ranges.
714            </p>
715         </div>
716         <div id="conformance">
717            <h2 id="rfc.section.1.1"><a href="#rfc.section.1.1">1.1</a>&nbsp;<a href="#conformance">Conformance and Error Handling</a></h2>
718            <div id="rfc.section.1.1.p.1">
719               <p>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD
720                  NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted
721                  as described in <a href="#RFC2119" id="rfc.xref.RFC2119.1"><cite title="Key words for use in RFCs to Indicate Requirement Levels">[RFC2119]</cite></a>.
722               </p>
723            </div>
724            <div id="rfc.section.1.1.p.2">
725               <p>Conformance criteria and considerations regarding error handling are defined in <a href="p1-messaging.html#conformance" title="Conformance and Error Handling">Section 2.5</a> of <a href="#RFC7230" id="rfc.xref.RFC7230.1"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[RFC7230]</cite></a>.
726               </p>
727            </div>
728         </div>
729         <div id="notation">
730            <h2 id="rfc.section.1.2"><a href="#rfc.section.1.2">1.2</a>&nbsp;<a href="#notation">Syntax Notation</a></h2>
731            <div id="rfc.section.1.2.p.1">
732               <p>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 a list extension, defined in <a href="p1-messaging.html#abnf.extension" title="ABNF List Extension: #rule">Section 7</a> of <a href="#RFC7230" id="rfc.xref.RFC7230.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[RFC7230]</cite></a>, that allows for compact definition of comma-separated lists using a '#' operator
733                  (similar to how the '*' operator indicates repetition). <a href="#imported.abnf" title="Imported ABNF">Appendix&nbsp;C</a> describes rules imported from other documents. <a href="#collected.abnf" title="Collected ABNF">Appendix&nbsp;D</a> shows the collected grammar with all list operators expanded to standard ABNF notation.
734               </p>
735            </div>
736         </div>
737      </div>
738      <div id="range.units">
739         <h1 id="rfc.section.2"><a href="#rfc.section.2">2.</a>&nbsp;<a href="#range.units">Range Units</a></h1>
740         <div id="rfc.section.2.p.1">
741            <p>A representation can be partitioned into subranges according to various structural
742               units, depending on the structure inherent in the representation's media type. This
743               "<dfn>range unit</dfn>" is used in the <a href="#header.accept-ranges" class="smpl">Accept-Ranges</a> (<a href="#header.accept-ranges" id="rfc.xref.header.accept-ranges.1" title="Accept-Ranges">Section&nbsp;2.3</a>) response header field to advertise support for range requests, the <a href="#header.range" class="smpl">Range</a> (<a href="#header.range" id="rfc.xref.header.range.1" title="Range">Section&nbsp;3.1</a>) request header field to delineate the parts of a representation that are requested,
744               and the <a href="#header.content-range" class="smpl">Content-Range</a> (<a href="#header.content-range" id="rfc.xref.header.content-range.1" title="Content-Range">Section&nbsp;4.2</a>) payload header field to describe which part of a representation is being transferred.
745            </p>
746         </div>
747         <div id="rfc.figure.u.1"><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="#range.units" class="smpl">range-unit</a>       = <a href="#byte.ranges" class="smpl">bytes-unit</a> / <a href="#range.units.other" class="smpl">other-range-unit</a>
748</pre></div>
749         <div id="byte.ranges">
750            <h2 id="rfc.section.2.1"><a href="#rfc.section.2.1">2.1</a>&nbsp;<a href="#byte.ranges">Byte Ranges</a></h2>
751            <div id="rfc.section.2.1.p.1">
752               <p>Since representation data is transferred in payloads as a sequence of octets, a byte
753                  range is a meaningful substructure for any representation transferable over HTTP (<a href="p2-semantics.html#representations" title="Representations">Section 3</a> of <a href="#RFC7231" id="rfc.xref.RFC7231.1"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[RFC7231]</cite></a>). The "bytes" range unit is defined for expressing subranges of the data's octet
754                  sequence.
755               </p>
756            </div>
757            <div id="rfc.figure.u.2"><pre class="inline"><span id="rfc.iref.g.4"></span>  <a href="#byte.ranges" class="smpl">bytes-unit</a>       = "bytes"
758</pre></div>
759            <div id="rule.ranges-specifier">
760               <div id="rfc.section.2.1.p.2">
761                  <p>        A byte-range request can specify a single range of bytes or a set of ranges within
762                     a single representation.
763                  </p>
764               </div>
765            </div>
766            <div id="rfc.figure.u.3"><pre class="inline"><span id="rfc.iref.g.5"></span><span id="rfc.iref.g.6"></span><span id="rfc.iref.g.7"></span><span id="rfc.iref.g.8"></span><span id="rfc.iref.g.9"></span><span id="rfc.iref.g.10"></span>  <a href="#rule.ranges-specifier" class="smpl">byte-ranges-specifier</a> = <a href="#byte.ranges" class="smpl">bytes-unit</a> "=" <a href="#rule.ranges-specifier" class="smpl">byte-range-set</a>
767  <a href="#rule.ranges-specifier" class="smpl">byte-range-set</a>  = 1#( <a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> / <a href="#rule.ranges-specifier" class="smpl">suffix-byte-range-spec</a> )
768  <a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> = <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> "-" [ <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> ]
769  <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a>  = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
770  <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a>   = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
771</pre></div>
772            <div id="rfc.section.2.1.p.3">
773               <p>The <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> value in a <a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> gives the byte-offset of the first byte in a range. The <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> value gives the byte-offset of the last byte in the range; that is, the byte positions
774                  specified are inclusive. Byte offsets start at zero.
775               </p>
776            </div>
777            <div id="rfc.section.2.1.p.4">
778               <p>Examples of <a href="#rule.ranges-specifier" class="smpl">byte-ranges-specifier</a> values:
779               </p>
780               <ul>
781                  <li>The first 500 bytes (byte offsets 0-499, inclusive): <span id="rfc.figure.u.4"><pre class="text">  bytes=0-499
782</pre></span>
783                  </li>
784                  <li>The second 500 bytes (byte offsets 500-999, inclusive): <span id="rfc.figure.u.5"><pre class="text">  bytes=500-999
785</pre></span>
786                  </li>
787               </ul>
788            </div>
789            <div id="rfc.section.2.1.p.5">
790               <p>A <a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> is invalid if the <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> value is present and less than the <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a>.
791               </p>
792            </div>
793            <div id="rfc.section.2.1.p.6">
794               <p>A client can limit the number of bytes requested without knowing the size of the selected
795                  representation. If the <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> value is absent, or if the value is greater than or equal to the current length of
796                  the representation data, the byte range is interpreted as the remainder of the representation
797                  (i.e., the server replaces the value of <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> with a value that is one less than the current length of the selected representation).
798               </p>
799            </div>
800            <div id="rfc.section.2.1.p.7">
801               <p>A client can request the last N bytes of the selected representation using a <a href="#rule.ranges-specifier" class="smpl">suffix-byte-range-spec</a>.
802               </p>
803            </div>
804            <div id="rfc.figure.u.6"><pre class="inline"><span id="rfc.iref.g.11"></span><span id="rfc.iref.g.12"></span>  <a href="#rule.ranges-specifier" class="smpl">suffix-byte-range-spec</a> = "-" <a href="#rule.ranges-specifier" class="smpl">suffix-length</a>
805  <a href="#rule.ranges-specifier" class="smpl">suffix-length</a> = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
806</pre></div>
807            <div id="rfc.section.2.1.p.8">
808               <p>If the selected representation is shorter than the specified <a href="#rule.ranges-specifier" class="smpl">suffix-length</a>, the entire representation is used.
809               </p>
810            </div>
811            <div id="rfc.section.2.1.p.9">
812               <p>Additional examples, assuming a representation of length 10000: </p>
813               <ul>
814                  <li>The final 500 bytes (byte offsets 9500-9999, inclusive): <span id="rfc.figure.u.7"><pre class="text">  bytes=-500
815</pre></span> Or: <span id="rfc.figure.u.8"><pre class="text">  bytes=9500-
816</pre></span>
817                  </li>
818                  <li>The first and last bytes only (bytes 0 and 9999): <span id="rfc.figure.u.9"><pre class="text">  bytes=0-0,-1
819</pre></span>
820                  </li>
821                  <li>Other valid (but not canonical) specifications of the second 500 bytes (byte offsets
822                     500-999, inclusive): <span id="rfc.figure.u.10"><pre class="text">  bytes=500-600,601-999
823  bytes=500-700,601-999
824</pre></span>
825                  </li>
826               </ul>
827            </div>
828            <div id="rfc.section.2.1.p.10">
829               <p>If a valid <a href="#rule.ranges-specifier" class="smpl">byte-range-set</a> includes at least one <a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> with a <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> that is less than the current length of the representation, or at least one <a href="#rule.ranges-specifier" class="smpl">suffix-byte-range-spec</a> with a non-zero <a href="#rule.ranges-specifier" class="smpl">suffix-length</a>, then the <a href="#rule.ranges-specifier" class="smpl">byte-range-set</a> is satisfiable. Otherwise, the <a href="#rule.ranges-specifier" class="smpl">byte-range-set</a> is unsatisfiable.
830               </p>
831            </div>
832            <div id="rfc.section.2.1.p.11">
833               <p>In the byte-range syntax, <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a>, <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a>, and <a href="#rule.ranges-specifier" class="smpl">suffix-length</a> are expressed as decimal number of octets. Since there is no predefined limit to the
834                  length of a payload, recipients <em class="bcp14">MUST</em> anticipate potentially large decimal numerals and prevent parsing errors due to integer
835                  conversion overflows.
836               </p>
837            </div>
838         </div>
839         <div id="range.units.other">
840            <h2 id="rfc.section.2.2"><a href="#rfc.section.2.2">2.2</a>&nbsp;<a href="#range.units.other">Other Range Units</a></h2>
841            <div id="rfc.section.2.2.p.1">
842               <p>Range units are intended to be extensible. New range units ought to be registered
843                  with IANA, as defined in <a href="#range.unit.registry" title="Range Unit Registry">Section&nbsp;5.1</a>.
844               </p>
845            </div>
846            <div id="rfc.figure.u.11"><pre class="inline"><span id="rfc.iref.g.13"></span>  <a href="#range.units.other" class="smpl">other-range-unit</a> = <a href="#imported.abnf" class="smpl">token</a>
847</pre></div>
848         </div>
849         <div id="header.accept-ranges">
850            <h2 id="rfc.section.2.3"><a href="#rfc.section.2.3">2.3</a>&nbsp;<a href="#header.accept-ranges">Accept-Ranges</a></h2>
851            <div id="rfc.section.2.3.p.1">
852               <p>The "Accept-Ranges" header field allows a server to indicate that it supports range
853                  requests for the target resource.
854               </p>
855            </div>
856            <div id="rfc.figure.u.12"><pre class="inline"><span id="rfc.iref.g.14"></span><span id="rfc.iref.g.15"></span>  <a href="#header.accept-ranges" class="smpl">Accept-Ranges</a>     = <a href="#header.accept-ranges" class="smpl">acceptable-ranges</a>
857  <a href="#header.accept-ranges" class="smpl">acceptable-ranges</a> = 1#<a href="#range.units" class="smpl">range-unit</a> / "none"
858</pre></div>
859            <div id="rfc.section.2.3.p.2">
860               <p>An origin server that supports byte-range requests for a given target resource <em class="bcp14">MAY</em> send
861               </p>
862            </div>
863            <div id="rfc.figure.u.13"><pre class="text">  Accept-Ranges: bytes
864</pre></div>
865            <div id="rfc.section.2.3.p.3">
866               <p>to indicate what range units are supported. A client <em class="bcp14">MAY</em> generate range requests without having received this header field for the resource
867                  involved. Range units are defined in <a href="#range.units" title="Range Units">Section&nbsp;2</a>.
868               </p>
869            </div>
870            <div id="rfc.section.2.3.p.4">
871               <p>A server that does not support any kind of range request for the target resource <em class="bcp14">MAY</em> send
872               </p>
873            </div>
874            <div id="rfc.figure.u.14"><pre class="text">  Accept-Ranges: none
875</pre></div>
876            <div id="rfc.section.2.3.p.5">
877               <p>to advise the client not to attempt a range request.</p>
878            </div>
879         </div>
880      </div>
881      <div id="range.requests">
882         <h1 id="rfc.section.3"><a href="#rfc.section.3">3.</a>&nbsp;<a href="#range.requests">Range Requests</a></h1>
883         <div id="header.range">
884            <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a href="#header.range">Range</a></h2>
885            <div id="rfc.section.3.1.p.1">
886               <p>The "Range" header field on a GET request modifies the method semantics to request
887                  transfer of only one or more subranges of the selected representation data, rather
888                  than the entire selected representation data.
889               </p>
890            </div>
891            <div id="rfc.figure.u.15"><pre class="inline"><span id="rfc.iref.g.16"></span>  <a href="#header.range" class="smpl">Range</a> = <a href="#rule.ranges-specifier" class="smpl">byte-ranges-specifier</a> / <a href="#header.range" class="smpl">other-ranges-specifier</a>
892  <a href="#header.range" class="smpl">other-ranges-specifier</a> = <a href="#range.units.other" class="smpl">other-range-unit</a> "=" <a href="#header.range" class="smpl">other-range-set</a>
893  <a href="#header.range" class="smpl">other-range-set</a> = 1*<a href="#imported.abnf" class="smpl">VCHAR</a>
894</pre></div>
895            <div id="rfc.section.3.1.p.2">
896               <p>A server <em class="bcp14">MAY</em> ignore the Range header field. However, origin servers and intermediate caches ought
897                  to support byte ranges when possible, since Range supports efficient recovery from
898                  partially failed transfers and partial retrieval of large representations. A server <em class="bcp14">MUST</em> ignore a Range header field received with a request method other than GET.
899               </p>
900            </div>
901            <div id="rfc.section.3.1.p.3">
902               <p>An origin server <em class="bcp14">MUST</em> ignore a Range header field that contains a range unit it does not understand. A proxy <em class="bcp14">MAY</em> discard a Range header field that contains a range unit it does not understand.
903               </p>
904            </div>
905            <div id="rfc.section.3.1.p.4">
906               <p>A server that supports range requests <em class="bcp14">MAY</em> ignore or reject a <a href="#header.range" class="smpl">Range</a> header field that consists of more than two overlapping ranges, or a set of many small
907                  ranges that are not listed in ascending order, since both are indications of either
908                  a broken client or a deliberate denial-of-service attack (<a href="#overlapping.ranges" title="Denial-of-Service Attacks Using Range">Section&nbsp;6.1</a>). A client <em class="bcp14">SHOULD NOT</em> request multiple ranges that are inherently less efficient to process and transfer
909                  than a single range that encompasses the same data.
910               </p>
911            </div>
912            <div id="rfc.section.3.1.p.5">
913               <p>A client that is requesting multiple ranges <em class="bcp14">SHOULD</em> list those ranges in ascending order (the order in which they would typically be received
914                  in a complete representation) unless there is a specific need to request a later part
915                  earlier. For example, a user agent processing a large representation with an internal
916                  catalog of parts might need to request later parts first, particularly if the representation
917                  consists of pages stored in reverse order and the user agent wishes to transfer one
918                  page at a time.
919               </p>
920            </div>
921            <div id="rfc.section.3.1.p.6">
922               <p>The Range header field is evaluated after evaluating the precondition header fields
923                  defined in <a href="#RFC7232" id="rfc.xref.RFC7232.1"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[RFC7232]</cite></a>, and only if the result in absence of the Range header field would be a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response. In other words, Range is ignored when a conditional GET would result in
924                  a <a href="p4-conditional.html#status.304" class="smpl">304 (Not Modified)</a> response.
925               </p>
926            </div>
927            <div id="rfc.section.3.1.p.7">
928               <p>The If-Range header field (<a href="#header.if-range" id="rfc.xref.header.if-range.1" title="If-Range">Section&nbsp;3.2</a>) can be used as a precondition to applying the Range header field.
929               </p>
930            </div>
931            <div id="rfc.section.3.1.p.8">
932               <p>If all of the preconditions are true, the server supports the Range header field for
933                  the target resource, and the specified range(s) are valid and satisfiable (as defined
934                  in <a href="#byte.ranges" title="Byte Ranges">Section&nbsp;2.1</a>), the server <em class="bcp14">SHOULD</em> send a <a href="#status.206" class="smpl">206 (Partial Content)</a> response with a payload containing one or more partial representations that correspond
935                  to the satisfiable ranges requested, as defined in <a href="#range.response" title="Responses to a Range Request">Section&nbsp;4</a>.
936               </p>
937            </div>
938            <div id="rfc.section.3.1.p.9">
939               <p>If all of the preconditions are true, the server supports the Range header field for
940                  the target resource, and the specified range(s) are invalid or unsatisfiable, the
941                  server <em class="bcp14">SHOULD</em> send a <a href="#status.416" class="smpl">416 (Range Not Satisfiable)</a> response.
942               </p>
943            </div>
944         </div>
945         <div id="header.if-range">
946            <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a>&nbsp;<a href="#header.if-range">If-Range</a></h2>
947            <div id="rfc.section.3.2.p.1">
948               <p>If a client has a partial copy of a representation and wishes to have an up-to-date
949                  copy of the entire representation, it could use the <a href="#header.range" class="smpl">Range</a> header field with a conditional GET (using either or both of <a href="p4-conditional.html#header.if-unmodified-since" class="smpl">If-Unmodified-Since</a> and <a href="p4-conditional.html#header.if-match" class="smpl">If-Match</a>.) However, if the precondition fails because the representation has been modified,
950                  the client would then have to make a second request to obtain the entire current representation.
951               </p>
952            </div>
953            <div id="rfc.section.3.2.p.2">
954               <p>The "If-Range" header field allows a client to "short-circuit" the second request.
955                  Informally, its meaning is as follows: if the representation is unchanged, send me
956                  the part(s) that I am requesting in Range; otherwise, send me the entire representation.
957               </p>
958            </div>
959            <div id="rfc.figure.u.16"><pre class="inline"><span id="rfc.iref.g.17"></span>  <a href="#header.if-range" class="smpl">If-Range</a> = <a href="#imported.abnf" class="smpl">entity-tag</a> / <a href="#imported.abnf" class="smpl">HTTP-date</a>
960</pre></div>
961            <div id="rfc.section.3.2.p.3">
962               <p>A client <em class="bcp14">MUST NOT</em> generate an If-Range header field in a request that does not contain a <a href="#header.range" class="smpl">Range</a> header field. A server <em class="bcp14">MUST</em> ignore an If-Range header field received in a request that does not contain a <a href="#header.range" class="smpl">Range</a> header field. An origin server <em class="bcp14">MUST</em> ignore an If-Range header field received in a request for a target resource that does
963                  not support Range requests.
964               </p>
965            </div>
966            <div id="rfc.section.3.2.p.4">
967               <p>A client <em class="bcp14">MUST NOT</em> generate an If-Range header field containing an entity-tag that is marked as weak.
968                  A client <em class="bcp14">MUST NOT</em> generate an If-Range header field containing an <a href="#imported.abnf" class="smpl">HTTP-date</a> unless the client has no entity-tag for the corresponding representation and the date
969                  is a strong validator in the sense defined by <a href="p4-conditional.html#lastmod.comparison" title="Comparison">Section 2.2.2</a> of <a href="#RFC7232" id="rfc.xref.RFC7232.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[RFC7232]</cite></a>.
970               </p>
971            </div>
972            <div id="rfc.section.3.2.p.5">
973               <p>A server that evaluates an If-Range precondition <em class="bcp14">MUST</em> use the strong comparison function when comparing entity-tags (<a href="p4-conditional.html#entity.tag.comparison" title="Comparison">Section 2.3.2</a> of <a href="#RFC7232" id="rfc.xref.RFC7232.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[RFC7232]</cite></a>) and <em class="bcp14">MUST</em> evaluate the condition as false if an <a href="#imported.abnf" class="smpl">HTTP-date</a> validator is provided that is not a strong validator in the sense defined by <a href="p4-conditional.html#lastmod.comparison" title="Comparison">Section 2.2.2</a> of <a href="#RFC7232" id="rfc.xref.RFC7232.4"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[RFC7232]</cite></a>. A valid <a href="#imported.abnf" class="smpl">entity-tag</a> can be distinguished from a valid <a href="#imported.abnf" class="smpl">HTTP-date</a> by examining the first two characters for a DQUOTE.
974               </p>
975            </div>
976            <div id="rfc.section.3.2.p.6">
977               <p>If the validator given in the If-Range header field matches the current validator
978                  for the selected representation of the target resource, then the server <em class="bcp14">SHOULD</em> process the <a href="#header.range" class="smpl">Range</a> header field as requested. If the validator does not match, the server <em class="bcp14">MUST</em> ignore the <a href="#header.range" class="smpl">Range</a> header field. Note that this comparison by exact match, including when the validator
979                  is an <a href="#imported.abnf" class="smpl">HTTP-date</a>, differs from the "earlier than or equal to" comparison used when evaluating an <a href="p4-conditional.html#header.if-unmodified-since" class="smpl">If-Unmodified-Since</a> conditional.
980               </p>
981            </div>
982         </div>
983      </div>
984      <div id="range.response">
985         <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a href="#range.response">Responses to a Range Request</a></h1>
986         <div id="status.206">
987            <h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a>&nbsp;<a href="#status.206">206 Partial Content</a></h2>
988            <div id="rfc.section.4.1.p.1">
989               <p>The <dfn>206 (Partial Content)</dfn> status code indicates that the server is successfully fulfilling a range request for
990                  the target resource by transferring one or more parts of the selected representation
991                  that correspond to the satisfiable ranges found in the request's <a href="#header.range" class="smpl">Range</a> header field (<a href="#header.range" id="rfc.xref.header.range.2" title="Range">Section&nbsp;3.1</a>).
992               </p>
993            </div>
994            <div id="rfc.section.4.1.p.2">
995               <p>If a single part is being transferred, the server generating the 206 response <em class="bcp14">MUST</em> generate a <a href="#header.content-range" class="smpl">Content-Range</a> header field, describing what range of the selected representation is enclosed, and
996                  a payload consisting of the range. For example:
997               </p>
998            </div>
999            <div id="rfc.figure.u.17"><pre class="text">HTTP/1.1 206 Partial Content
1000Date: Wed, 15 Nov 1995 06:25:24 GMT
1001Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT
1002Content-Range: bytes 21010-47021/47022
1003Content-Length: 26012
1004Content-Type: image/gif
1005
1006... 26012 bytes of partial image data ...
1007</pre></div>
1008            <div id="rfc.section.4.1.p.3">
1009               <p>If multiple parts are being transferred, the server generating the 206 response <em class="bcp14">MUST</em> generate a "multipart/byteranges" payload, as defined in <a href="#internet.media.type.multipart.byteranges" title="Internet Media Type multipart/byteranges">Appendix&nbsp;A</a>, and a <a href="p2-semantics.html#header.content-type" class="smpl">Content-Type</a> header field containing the multipart/byteranges media type and its required boundary
1010                  parameter. To avoid confusion with single-part responses, a server <em class="bcp14">MUST NOT</em> generate a <a href="#header.content-range" class="smpl">Content-Range</a> header field in the HTTP header section of a multiple part response (this field will
1011                  be sent in each part instead).
1012               </p>
1013            </div>
1014            <div id="rfc.section.4.1.p.4">
1015               <p>Within the header area of each body part in the multipart payload, the server <em class="bcp14">MUST</em> generate a <a href="#header.content-range" class="smpl">Content-Range</a> header field corresponding to the range being enclosed in that body part. If the selected
1016                  representation would have had a <a href="p2-semantics.html#header.content-type" class="smpl">Content-Type</a> header field in a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response, the server <em class="bcp14">SHOULD</em> generate that same <a href="p2-semantics.html#header.content-type" class="smpl">Content-Type</a> field in the header area of each body part. For example:
1017               </p>
1018            </div>
1019            <div id="rfc.figure.u.18"><pre class="text">HTTP/1.1 206 Partial Content
1020Date: Wed, 15 Nov 1995 06:25:24 GMT
1021Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT
1022Content-Length: 1741
1023Content-Type: multipart/byteranges; boundary=THIS_STRING_SEPARATES
1024
1025--THIS_STRING_SEPARATES
1026Content-Type: application/pdf
1027Content-Range: bytes 500-999/8000
1028
1029...the first range...
1030--THIS_STRING_SEPARATES
1031Content-Type: application/pdf
1032Content-Range: bytes 7000-7999/8000
1033
1034...the second range
1035--THIS_STRING_SEPARATES--
1036</pre></div>
1037            <div id="rfc.section.4.1.p.5">
1038               <p>When multiple ranges are requested, a server <em class="bcp14">MAY</em> coalesce any of the ranges that overlap, or that are separated by a gap that is smaller
1039                  than the overhead of sending multiple parts, regardless of the order in which the
1040                  corresponding byte-range-spec appeared in the received <a href="#header.range" class="smpl">Range</a> header field. Since the typical overhead between parts of a multipart/byteranges payload
1041                  is around 80 bytes, depending on the selected representation's media type and the
1042                  chosen boundary parameter length, it can be less efficient to transfer many small
1043                  disjoint parts than it is to transfer the entire selected representation.
1044               </p>
1045            </div>
1046            <div id="rfc.section.4.1.p.6">
1047               <p>A server <em class="bcp14">MUST NOT</em> generate a multipart response to a request for a single range, since a client that
1048                  does not request multiple parts might not support multipart responses. However, a
1049                  server <em class="bcp14">MAY</em> generate a multipart/byteranges payload with only a single body part if multiple ranges
1050                  were requested and only one range was found to be satisfiable or only one range remained
1051                  after coalescing. A client that cannot process a multipart/byteranges response <em class="bcp14">MUST NOT</em> generate a request that asks for multiple ranges.
1052               </p>
1053            </div>
1054            <div id="rfc.section.4.1.p.7">
1055               <p>When a multipart response payload is generated, the server <em class="bcp14">SHOULD</em> send the parts in the same order that the corresponding byte-range-spec appeared in
1056                  the received <a href="#header.range" class="smpl">Range</a> header field, excluding those ranges that were deemed unsatisfiable or that were coalesced
1057                  into other ranges. A client that receives a multipart response <em class="bcp14">MUST</em> inspect the <a href="#header.content-range" class="smpl">Content-Range</a> header field present in each body part in order to determine which range is contained
1058                  in that body part; a client cannot rely on receiving the same ranges that it requested,
1059                  nor the same order that it requested.
1060               </p>
1061            </div>
1062            <div id="rfc.section.4.1.p.8">
1063               <p>When a 206 response is generated, the server <em class="bcp14">MUST</em> generate the following header fields, in addition to those required above, if the
1064                  field would have been sent in a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response to the same request: <a href="p2-semantics.html#header.date" class="smpl">Date</a>, <a href="p6-cache.html#header.cache-control" class="smpl">Cache-Control</a>, <a href="p4-conditional.html#header.etag" class="smpl">ETag</a>, <a href="p6-cache.html#header.expires" class="smpl">Expires</a>, <a href="p2-semantics.html#header.content-location" class="smpl">Content-Location</a>, and <a href="p2-semantics.html#header.vary" class="smpl">Vary</a>.
1065               </p>
1066            </div>
1067            <div id="rfc.section.4.1.p.9">
1068               <p>If a 206 is generated in response to a request with an <a href="#header.if-range" class="smpl">If-Range</a> header field, the sender <em class="bcp14">SHOULD NOT</em> generate other representation header fields beyond those required above, because the
1069                  client is understood to already have a prior response containing those header fields.
1070                  Otherwise, the sender <em class="bcp14">MUST</em> generate all of the representation header fields that would have been sent in a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response to the same request.
1071               </p>
1072            </div>
1073            <div id="rfc.section.4.1.p.10">
1074               <p>A 206 response is cacheable by default; i.e., unless otherwise indicated by explicit
1075                  cache controls (see <a href="p6-cache.html#heuristic.freshness" title="Calculating Heuristic Freshness">Section 4.2.2</a> of <a href="#RFC7234" id="rfc.xref.RFC7234.1"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Caching">[RFC7234]</cite></a>).
1076               </p>
1077            </div>
1078         </div>
1079         <div id="header.content-range">
1080            <h2 id="rfc.section.4.2"><a href="#rfc.section.4.2">4.2</a>&nbsp;<a href="#header.content-range">Content-Range</a></h2>
1081            <div id="rfc.section.4.2.p.1">
1082               <p>The "Content-Range" header field is sent in a single part <a href="#status.206" class="smpl">206 (Partial Content)</a> response to indicate the partial range of the selected representation enclosed as
1083                  the message payload, sent in each part of a multipart 206 response to indicate the
1084                  range enclosed within each body part, and sent in <a href="#status.416" class="smpl">416 (Range Not Satisfiable)</a> responses to provide information about the selected representation.
1085               </p>
1086            </div>
1087            <div id="rfc.figure.u.19"><pre class="inline"><span id="rfc.iref.g.18"></span><span id="rfc.iref.g.19"></span><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><span id="rfc.iref.g.25"></span>  <a href="#header.content-range" class="smpl">Content-Range</a>       = <a href="#header.content-range" class="smpl">byte-content-range</a>
1088                      / <a href="#header.content-range" class="smpl">other-content-range</a>
1089                         
1090  <a href="#header.content-range" class="smpl">byte-content-range</a>  = <a href="#byte.ranges" class="smpl">bytes-unit</a> <a href="#imported.abnf" class="smpl">SP</a>
1091                        ( <a href="#header.content-range" class="smpl">byte-range-resp</a> / <a href="#header.content-range" class="smpl">unsatisfied-range</a> )
1092
1093  <a href="#header.content-range" class="smpl">byte-range-resp</a>     = <a href="#header.content-range" class="smpl">byte-range</a> "/" ( <a href="#header.content-range" class="smpl">complete-length</a> / "*" )
1094  <a href="#header.content-range" class="smpl">byte-range</a>          = <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> "-" <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a>
1095  <a href="#header.content-range" class="smpl">unsatisfied-range</a>   = "*/" <a href="#header.content-range" class="smpl">complete-length</a>
1096                         
1097  <a href="#header.content-range" class="smpl">complete-length</a>     = 1*<a href="#imported.abnf" class="smpl">DIGIT</a>
1098 
1099  <a href="#header.content-range" class="smpl">other-content-range</a> = <a href="#range.units.other" class="smpl">other-range-unit</a> <a href="#imported.abnf" class="smpl">SP</a> <a href="#header.content-range" class="smpl">other-range-resp</a>
1100  <a href="#header.content-range" class="smpl">other-range-resp</a>    = *<a href="#imported.abnf" class="smpl">CHAR</a>
1101</pre></div>
1102            <div id="rfc.section.4.2.p.2">
1103               <p>If a <a href="#status.206" class="smpl">206 (Partial Content)</a> response contains a <a href="#header.content-range" class="smpl">Content-Range</a> header field with a <a href="#range.units" class="smpl">range unit</a> (<a href="#range.units" title="Range Units">Section&nbsp;2</a>) that the recipient does not understand, the recipient <em class="bcp14">MUST NOT</em> attempt to recombine it with a stored representation. A proxy that receives such a
1104                  message <em class="bcp14">SHOULD</em> forward it downstream.
1105               </p>
1106            </div>
1107            <div id="rfc.section.4.2.p.3">
1108               <p>For byte ranges, a sender <em class="bcp14">SHOULD</em> indicate the complete length of the representation from which the range has been extracted,
1109                  unless the complete length is unknown or difficult to determine. An asterisk character
1110                  ("*") in place of the complete-length indicates that the representation length was
1111                  unknown when the header field was generated.
1112               </p>
1113            </div>
1114            <div id="rfc.section.4.2.p.4">
1115               <p>The following example illustrates when the complete length of the selected representation
1116                  is known by the sender to be 1234 bytes:
1117               </p>
1118            </div>
1119            <div id="rfc.figure.u.20"><pre class="text">  Content-Range: bytes 42-1233/1234
1120</pre></div>
1121            <div id="rfc.section.4.2.p.5">
1122               <p>and this second example illustrates when the complete length is unknown:</p>
1123            </div>
1124            <div id="rfc.figure.u.21"><pre class="text">  Content-Range: bytes 42-1233/*
1125</pre></div>
1126            <div id="rfc.section.4.2.p.6">
1127               <p>A Content-Range field value is invalid if it contains a <a href="#header.content-range" class="smpl">byte-range-resp</a> that has a <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> value less than its <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> value, or a <a href="#header.content-range" class="smpl">complete-length</a> value less than or equal to its <a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> value. The recipient of an invalid <a href="#header.content-range" class="smpl">Content-Range</a> <em class="bcp14">MUST NOT</em> attempt to recombine the received content with a stored representation.
1128               </p>
1129            </div>
1130            <div id="rfc.section.4.2.p.7">
1131               <p>A server generating a <a href="#status.416" class="smpl">416 (Range Not Satisfiable)</a> response to a byte-range request <em class="bcp14">SHOULD</em> send a Content-Range header field with an <a href="#header.content-range" class="smpl">unsatisfied-range</a> value, as in the following example:
1132               </p>
1133            </div>
1134            <div id="rfc.figure.u.22"><pre class="text">  Content-Range: bytes */1234
1135</pre></div>
1136            <div id="rfc.section.4.2.p.8">
1137               <p>The complete-length in a 416 response indicates the current length of the selected
1138                  representation.
1139               </p>
1140            </div>
1141            <div id="rfc.section.4.2.p.9">
1142               <p>The Content-Range header field has no meaning for status codes that do not explicitly
1143                  describe its semantic. For this specification, only the <a href="#status.206" class="smpl">206 (Partial Content)</a> and <a href="#status.416" class="smpl">416 (Range Not Satisfiable)</a> status codes describe a meaning for Content-Range.
1144               </p>
1145            </div>
1146            <div id="rfc.section.4.2.p.10">
1147               <p>The following are examples of Content-Range values in which the selected representation
1148                  contains a total of 1234 bytes:
1149               </p>
1150               <ul>
1151                  <li>The first 500 bytes: <span id="rfc.figure.u.23"><pre class="text">  Content-Range: bytes 0-499/1234
1152</pre></span>
1153                  </li>
1154                  <li>The second 500 bytes: <span id="rfc.figure.u.24"><pre class="text">  Content-Range: bytes 500-999/1234
1155</pre></span>
1156                  </li>
1157                  <li>All except for the first 500 bytes: <span id="rfc.figure.u.25"><pre class="text">  Content-Range: bytes 500-1233/1234
1158</pre></span>
1159                  </li>
1160                  <li>The last 500 bytes: <span id="rfc.figure.u.26"><pre class="text">  Content-Range: bytes 734-1233/1234
1161</pre></span>
1162                  </li>
1163               </ul>
1164            </div>
1165         </div>
1166         <div id="combining.byte.ranges">
1167            <h2 id="rfc.section.4.3"><a href="#rfc.section.4.3">4.3</a>&nbsp;<a href="#combining.byte.ranges">Combining Ranges</a></h2>
1168            <div id="rfc.section.4.3.p.1">
1169               <p>A response might transfer only a subrange of a representation if the connection closed
1170                  prematurely or if the request used one or more Range specifications. After several
1171                  such transfers, a client might have received several ranges of the same representation.
1172                  These ranges can only be safely combined if they all have in common the same strong
1173                  validator (<a href="p4-conditional.html#weak.and.strong.validators" title="Weak versus Strong">Section 2.1</a> of <a href="#RFC7232" id="rfc.xref.RFC7232.5"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[RFC7232]</cite></a>).
1174               </p>
1175            </div>
1176            <div id="rfc.section.4.3.p.2">
1177               <p>A client that has received multiple partial responses to GET requests on a target
1178                  resource <em class="bcp14">MAY</em> combine those responses into a larger continuous range if they share the same strong
1179                  validator.
1180               </p>
1181            </div>
1182            <div id="rfc.section.4.3.p.3">
1183               <p>If the most recent response is an incomplete <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response, then the header fields of that response are used for any combined response
1184                  and replace those of the matching stored responses.
1185               </p>
1186            </div>
1187            <div id="rfc.section.4.3.p.4">
1188               <p>If the most recent response is a <a href="#status.206" class="smpl">206 (Partial Content)</a> response and at least one of the matching stored responses is a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a>, then the combined response header fields consist of the most recent 200 response's
1189                  header fields. If all of the matching stored responses are 206 responses, then the
1190                  stored response with the most recent header fields is used as the source of header
1191                  fields for the combined response, except that the client <em class="bcp14">MUST</em> use other header fields provided in the new response, aside from <a href="#header.content-range" class="smpl">Content-Range</a>, to replace all instances of the corresponding header fields in the stored response.
1192               </p>
1193            </div>
1194            <div id="rfc.section.4.3.p.5">
1195               <p>The combined response message body consists of the union of partial content ranges
1196                  in the new response and each of the selected responses. If the union consists of the
1197                  entire range of the representation, then the client <em class="bcp14">MUST</em> process the combined response as if it were a complete <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response, including a <a href="p1-messaging.html#header.content-length" class="smpl">Content-Length</a> header field that reflects the complete length. Otherwise, the client <em class="bcp14">MUST</em> process the set of continuous ranges as one of the following: an incomplete <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response if the combined response is a prefix of the representation, a single <a href="#status.206" class="smpl">206 (Partial Content)</a> response containing a multipart/byteranges body, or multiple <a href="#status.206" class="smpl">206 (Partial Content)</a> responses, each with one continuous range that is indicated by a <a href="#header.content-range" class="smpl">Content-Range</a> header field.
1198               </p>
1199            </div>
1200         </div>
1201         <div id="status.416">
1202            <h2 id="rfc.section.4.4"><a href="#rfc.section.4.4">4.4</a>&nbsp;<a href="#status.416">416 Range Not Satisfiable</a></h2>
1203            <div id="rfc.section.4.4.p.1">
1204               <p>The <dfn>416 (Range Not Satisfiable)</dfn> status code indicates that none of the ranges in the request's <a href="#header.range" class="smpl">Range</a> header field (<a href="#header.range" id="rfc.xref.header.range.3" title="Range">Section&nbsp;3.1</a>) overlap the current extent of the selected resource or that the set of ranges requested
1205                  has been rejected due to invalid ranges or an excessive request of small or overlapping
1206                  ranges.
1207               </p>
1208            </div>
1209            <div id="rfc.section.4.4.p.2">
1210               <p>For byte ranges, failing to overlap the current extent means that the <a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> of all of the <a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> values were greater than the current length of the selected representation. When this
1211                  status code is generated in response to a byte-range request, the sender <em class="bcp14">SHOULD</em> generate a <a href="#header.content-range" class="smpl">Content-Range</a> header field specifying the current length of the selected representation (<a href="#header.content-range" id="rfc.xref.header.content-range.2" title="Content-Range">Section&nbsp;4.2</a>).
1212               </p>
1213            </div>
1214            <div id="rfc.figure.u.27">
1215               <p>For example:</p><pre class="text">HTTP/1.1 416 Range Not Satisfiable
1216Date: Fri, 20 Jan 2012 15:41:54 GMT
1217Content-Range: bytes */47022
1218</pre></div>
1219            <div class="note">
1220               <div id="rfc.section.4.4.p.3">
1221                  <p><b>Note:</b> Because servers are free to ignore <a href="#header.range" class="smpl">Range</a>, many implementations will simply respond with the entire selected representation
1222                     in a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> response. That is partly because most clients are prepared to receive a <a href="p2-semantics.html#status.200" class="smpl">200 (OK)</a> to complete the task (albeit less efficiently) and partly because clients might not
1223                     stop making an invalid partial request until they have received a complete representation.
1224                     Thus, clients cannot depend on receiving a <a href="#status.416" class="smpl">416 (Range Not Satisfiable)</a> response even when it is most appropriate.
1225                  </p>
1226               </div>
1227            </div>
1228         </div>
1229      </div>
1230      <div id="IANA.considerations">
1231         <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a href="#IANA.considerations">IANA Considerations</a></h1>
1232         <div id="range.unit.registry">
1233            <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a>&nbsp;<a href="#range.unit.registry">Range Unit Registry</a></h2>
1234            <div id="rfc.section.5.1.p.1">
1235               <p>The "HTTP Range Unit Registry" defines the namespace for the range unit names and
1236                  refers to their corresponding specifications. The registry has been created and is
1237                  now maintained at &lt;<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>&gt;.
1238               </p>
1239            </div>
1240            <div id="range.unit.registry.procedure">
1241               <h3 id="rfc.section.5.1.1"><a href="#rfc.section.5.1.1">5.1.1</a>&nbsp;<a href="#range.unit.registry.procedure">Procedure</a></h3>
1242               <div id="rfc.section.5.1.1.p.1">
1243                  <p>Registration of an HTTP Range Unit <em class="bcp14">MUST</em> include the following fields:
1244                  </p>
1245                  <ul>
1246                     <li>Name</li>
1247                     <li>Description</li>
1248                     <li>Pointer to specification text</li>
1249                  </ul>
1250               </div>
1251               <div id="rfc.section.5.1.1.p.2">
1252                  <p>Values to be added to this namespace require IETF Review (see <a href="#RFC5226" id="rfc.xref.RFC5226.1"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>, <a href="https://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a>).
1253                  </p>
1254               </div>
1255            </div>
1256            <div id="range.unit.registration">
1257               <h3 id="rfc.section.5.1.2"><a href="#rfc.section.5.1.2">5.1.2</a>&nbsp;<a href="#range.unit.registration">Registrations</a></h3>
1258               <div id="rfc.section.5.1.2.p.1">
1259                  <p>The initial range unit registry contains the registrations below:</p>
1260               </div>
1261               <div id="rfc.table.1">
1262                  <div id="iana.range.units.table"></div>
1263                  <table class="tt full left" cellpadding="3" cellspacing="0">
1264                     <thead>
1265                        <tr>
1266                           <th>Range Unit Name</th>
1267                           <th>Description</th>
1268                           <th>Reference</th>
1269                        </tr>
1270                     </thead>
1271                     <tbody>
1272                        <tr>
1273                           <td class="left">bytes</td>
1274                           <td class="left">a range of octets</td>
1275                           <td class="left"><a href="#byte.ranges" title="Byte Ranges">Section&nbsp;2.1</a></td>
1276                        </tr>
1277                        <tr>
1278                           <td class="left">none</td>
1279                           <td class="left">reserved as keyword, indicating no ranges are supported</td>
1280                           <td class="left"><a href="#header.accept-ranges" id="rfc.xref.header.accept-ranges.2" title="Accept-Ranges">Section&nbsp;2.3</a></td>
1281                        </tr>
1282                     </tbody>
1283                  </table>
1284               </div>
1285               <div id="rfc.section.5.1.2.p.2">
1286                  <p>The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
1287               </div>
1288            </div>
1289         </div>
1290         <div id="status.code.registration">
1291            <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</a>&nbsp;<a href="#status.code.registration">Status Code Registration</a></h2>
1292            <div id="rfc.section.5.2.p.1">
1293               <p>The "Hypertext Transfer Protocol (HTTP) Status Code Registry" located at &lt;<a href="http://www.iana.org/assignments/http-status-codes">http://www.iana.org/assignments/http-status-codes</a>&gt; has been updated to include the registrations below:
1294               </p>
1295            </div>
1296            <div id="rfc.table.2">
1297               <div id="iana.status.code.registration.table"></div>
1298               <table class="tt full left" cellpadding="3" cellspacing="0">
1299                  <thead>
1300                     <tr>
1301                        <th>Value</th>
1302                        <th>Description</th>
1303                        <th>Reference</th>
1304                     </tr>
1305                  </thead>
1306                  <tbody>
1307                     <tr>
1308                        <td class="left">206</td>
1309                        <td class="left">Partial Content</td>
1310                        <td class="left"><a href="#status.206" id="rfc.xref.status.206.1" title="206 Partial Content">Section&nbsp;4.1</a>
1311                        </td>
1312                     </tr>
1313                     <tr>
1314                        <td class="left">416</td>
1315                        <td class="left">Range Not Satisfiable</td>
1316                        <td class="left"><a href="#status.416" id="rfc.xref.status.416.1" title="416 Range Not Satisfiable">Section&nbsp;4.4</a>
1317                        </td>
1318                     </tr>
1319                  </tbody>
1320               </table>
1321            </div>
1322         </div>
1323         <div id="header.field.registration">
1324            <h2 id="rfc.section.5.3"><a href="#rfc.section.5.3">5.3</a>&nbsp;<a href="#header.field.registration">Header Field Registration</a></h2>
1325            <div id="rfc.section.5.3.p.1">
1326               <p>HTTP header fields are registered within the "Message Headers" registry maintained
1327                  at &lt;<a href="http://www.iana.org/assignments/message-headers/">http://www.iana.org/assignments/message-headers/</a>&gt;.
1328               </p>
1329            </div>
1330            <div id="rfc.section.5.3.p.2">
1331               <p>This document defines the following HTTP header fields, so their associated registry
1332                  entries have been updated according to the permanent registrations below (see <a href="#BCP90" id="rfc.xref.BCP90.1"><cite title="Registration Procedures for Message Header Fields">[BCP90]</cite></a>):
1333               </p>
1334            </div>
1335            <div id="rfc.table.3">
1336               <div id="iana.header.registration.table"></div>
1337               <table class="tt full left" cellpadding="3" cellspacing="0">
1338                  <thead>
1339                     <tr>
1340                        <th>Header Field Name</th>
1341                        <th>Protocol</th>
1342                        <th>Status</th>
1343                        <th>Reference</th>
1344                     </tr>
1345                  </thead>
1346                  <tbody>
1347                     <tr>
1348                        <td class="left">Accept-Ranges</td>
1349                        <td class="left">http</td>
1350                        <td class="left">standard</td>
1351                        <td class="left"><a href="#header.accept-ranges" id="rfc.xref.header.accept-ranges.3" title="Accept-Ranges">Section&nbsp;2.3</a>
1352                        </td>
1353                     </tr>
1354                     <tr>
1355                        <td class="left">Content-Range</td>
1356                        <td class="left">http</td>
1357                        <td class="left">standard</td>
1358                        <td class="left"><a href="#header.content-range" id="rfc.xref.header.content-range.3" title="Content-Range">Section&nbsp;4.2</a>
1359                        </td>
1360                     </tr>
1361                     <tr>
1362                        <td class="left">If-Range</td>
1363                        <td class="left">http</td>
1364                        <td class="left">standard</td>
1365                        <td class="left"><a href="#header.if-range" id="rfc.xref.header.if-range.2" title="If-Range">Section&nbsp;3.2</a>
1366                        </td>
1367                     </tr>
1368                     <tr>
1369                        <td class="left">Range</td>
1370                        <td class="left">http</td>
1371                        <td class="left">standard</td>
1372                        <td class="left"><a href="#header.range" id="rfc.xref.header.range.4" title="Range">Section&nbsp;3.1</a>
1373                        </td>
1374                     </tr>
1375                  </tbody>
1376               </table>
1377            </div>
1378            <div id="rfc.section.5.3.p.3">
1379               <p>The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
1380            </div>
1381         </div>
1382         <div id="internet.media.type.http">
1383            <h2 id="rfc.section.5.4"><a href="#rfc.section.5.4">5.4</a>&nbsp;<a href="#internet.media.type.http">Internet Media Type Registration</a></h2>
1384            <div id="rfc.section.5.4.p.1">
1385               <p>IANA maintains the registry of Internet media types <a href="#BCP13" id="rfc.xref.BCP13.1"><cite title="Media Type Specifications and Registration Procedures">[BCP13]</cite></a> at &lt;<a href="http://www.iana.org/assignments/media-types">http://www.iana.org/assignments/media-types</a>&gt;.
1386               </p>
1387            </div>
1388            <div id="rfc.section.5.4.p.2">
1389               <p>This document serves as the specification for the Internet media type "multipart/byteranges".
1390                  The following has been registered with IANA.
1391               </p>
1392            </div>
1393            <div id="internet.media.type.multipart.byteranges.reg">
1394               <h3 id="rfc.section.5.4.1"><a href="#rfc.section.5.4.1">5.4.1</a>&nbsp;<a href="#internet.media.type.multipart.byteranges.reg">Internet Media Type multipart/byteranges</a></h3>
1395               <div id="rfc.section.5.4.1.p.1">
1396                  <dl>
1397                     <dt>Type name:</dt>
1398                     <dd>multipart</dd>
1399                     <dt>Subtype name:</dt>
1400                     <dd>byteranges</dd>
1401                     <dt>Required parameters:</dt>
1402                     <dd>boundary</dd>
1403                     <dt>Optional parameters:</dt>
1404                     <dd>N/A</dd>
1405                     <dt>Encoding considerations:</dt>
1406                     <dd>only "7bit", "8bit", or "binary" are permitted</dd>
1407                     <dt>Security considerations:</dt>
1408                     <dd>see <a href="#security.considerations" title="Security Considerations">Section&nbsp;6</a>
1409                     </dd>
1410                     <dt>Interoperability considerations:</dt>
1411                     <dd>N/A</dd>
1412                     <dt>Published specification:</dt>
1413                     <dd>This specification (see <a href="#internet.media.type.multipart.byteranges" title="Internet Media Type multipart/byteranges">Appendix&nbsp;A</a>).
1414                     </dd>
1415                     <dt>Applications that use this media type:</dt>
1416                     <dd>HTTP components supporting multiple ranges in a single request.</dd>
1417                     <dt>Fragment identifier considerations:</dt>
1418                     <dd>N/A</dd>
1419                     <dt>Additional information:</dt>
1420                     <dd>&nbsp;
1421                        <dl>
1422                           <dt>Deprecated alias names for this type:</dt>
1423                           <dd>N/A</dd>
1424                           <dt>Magic number(s):</dt>
1425                           <dd>N/A</dd>
1426                           <dt>File extension(s):</dt>
1427                           <dd>N/A</dd>
1428                           <dt>Macintosh file type code(s):</dt>
1429                           <dd>N/A</dd>
1430                        </dl>
1431                     </dd>
1432                     <dt>Person and email address to contact for further information:</dt>
1433                     <dd>See Authors' Addresses section.</dd>
1434                     <dt>Intended usage:</dt>
1435                     <dd>COMMON</dd>
1436                     <dt>Restrictions on usage:</dt>
1437                     <dd>N/A</dd>
1438                     <dt>Author:</dt>
1439                     <dd>See Authors' Addresses section.</dd>
1440                     <dt>Change controller:</dt>
1441                     <dd>IESG</dd>
1442                  </dl>
1443               </div>
1444            </div>
1445         </div>
1446      </div>
1447      <div id="security.considerations">
1448         <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a href="#security.considerations">Security Considerations</a></h1>
1449         <div id="rfc.section.6.p.1">
1450            <p>This section is meant to inform developers, information providers, and users of known
1451               security concerns specific to the HTTP range request mechanisms. More general security
1452               considerations are addressed in HTTP messaging <a href="#RFC7230" id="rfc.xref.RFC7230.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[RFC7230]</cite></a> and semantics <a href="#RFC7231" id="rfc.xref.RFC7231.2"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[RFC7231]</cite></a>.
1453            </p>
1454         </div>
1455         <div id="overlapping.ranges">
1456            <h2 id="rfc.section.6.1"><a href="#rfc.section.6.1">6.1</a>&nbsp;<a href="#overlapping.ranges">Denial-of-Service Attacks Using Range</a></h2>
1457            <div id="rfc.section.6.1.p.1">
1458               <p>Unconstrained multiple range requests are susceptible to denial-of-service attacks
1459                  because the effort required to request many overlapping ranges of the same data is
1460                  tiny compared to the time, memory, and bandwidth consumed by attempting to serve the
1461                  requested data in many parts. Servers ought to ignore, coalesce, or reject egregious
1462                  range requests, such as requests for more than two overlapping ranges or for many
1463                  small ranges in a single set, particularly when the ranges are requested out of order
1464                  for no apparent reason. Multipart range requests are not designed to support random
1465                  access.
1466               </p>
1467            </div>
1468         </div>
1469      </div>
1470      <div id="acks">
1471         <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a href="#acks">Acknowledgments</a></h1>
1472         <div id="rfc.section.7.p.1">
1473            <p>See <a href="p1-messaging.html#acks" title="Acknowledgments">Section 10</a> of <a href="#RFC7230" id="rfc.xref.RFC7230.4"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[RFC7230]</cite></a>.
1474            </p>
1475         </div>
1476      </div>
1477      <h1 id="rfc.references"><a id="rfc.section.8" href="#rfc.section.8">8.</a> References
1478      </h1>
1479      <h2 id="rfc.references.1"><a href="#rfc.section.8.1" id="rfc.section.8.1">8.1</a> Normative References
1480      </h2>
1481      <table>
1482         <tr>
1483            <td class="reference"><b id="RFC2046">[RFC2046]</b></td>
1484            <td class="top">Freed, N. and N. Borenstein, “<a href="https://tools.ietf.org/html/rfc2046">Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types</a>”, RFC&nbsp;2046, November&nbsp;1996.
1485            </td>
1486         </tr>
1487         <tr>
1488            <td class="reference"><b id="RFC2119">[RFC2119]</b></td>
1489            <td class="top">Bradner, S., “<a href="https://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>”, BCP&nbsp;14, RFC&nbsp;2119, March&nbsp;1997.
1490            </td>
1491         </tr>
1492         <tr>
1493            <td class="reference"><b id="RFC5234">[RFC5234]</b></td>
1494            <td class="top">Crocker, D., Ed. and P. Overell, “<a href="https://tools.ietf.org/html/rfc5234">Augmented BNF for Syntax Specifications: ABNF</a>”, STD&nbsp;68, RFC&nbsp;5234, January&nbsp;2008.
1495            </td>
1496         </tr>
1497         <tr>
1498            <td class="reference"><b id="RFC7230">[RFC7230]</b></td>
1499            <td class="top">Fielding, R., Ed. and J. Reschke, Ed., “<a href="https://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-latest">Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing</a>”, Internet-Draft&nbsp;draft-ietf-httpbis-p1-messaging-latest (work in progress), June&nbsp;2014.
1500            </td>
1501         </tr>
1502         <tr>
1503            <td class="reference"><b id="RFC7231">[RFC7231]</b></td>
1504            <td class="top">Fielding, R., Ed. and J. Reschke, Ed., “<a href="https://tools.ietf.org/html/draft-ietf-httpbis-p2-semantics-latest">Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content</a>”, Internet-Draft&nbsp;draft-ietf-httpbis-p2-semantics-latest (work in progress), June&nbsp;2014.
1505            </td>
1506         </tr>
1507         <tr>
1508            <td class="reference"><b id="RFC7232">[RFC7232]</b></td>
1509            <td class="top">Fielding, R., Ed. and J. Reschke, Ed., “<a href="https://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-latest">Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests</a>”, Internet-Draft&nbsp;draft-ietf-httpbis-p4-conditional-latest (work in progress), June&nbsp;2014.
1510            </td>
1511         </tr>
1512         <tr>
1513            <td class="reference"><b id="RFC7234">[RFC7234]</b></td>
1514            <td class="top">Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., “<a href="https://tools.ietf.org/html/draft-ietf-httpbis-p6-cache-latest">Hypertext Transfer Protocol (HTTP/1.1): Caching</a>”, Internet-Draft&nbsp;draft-ietf-httpbis-p6-cache-latest (work in progress), June&nbsp;2014.
1515            </td>
1516         </tr>
1517      </table>
1518      <h2 id="rfc.references.2"><a href="#rfc.section.8.2" id="rfc.section.8.2">8.2</a> Informative References
1519      </h2>
1520      <table>
1521         <tr>
1522            <td class="reference"><b id="BCP13">[BCP13]</b></td>
1523            <td class="top">Freed, N., Klensin, J., and T. Hansen, “<a href="https://tools.ietf.org/html/rfc6838">Media Type Specifications and Registration Procedures</a>”, BCP&nbsp;13, RFC&nbsp;6838, January&nbsp;2013.
1524            </td>
1525         </tr>
1526         <tr>
1527            <td class="reference"><b id="BCP90">[BCP90]</b></td>
1528            <td class="top">Klyne, G., Nottingham, M., and J. Mogul, “<a href="https://tools.ietf.org/html/rfc3864">Registration Procedures for Message Header Fields</a>”, BCP&nbsp;90, RFC&nbsp;3864, September&nbsp;2004.
1529            </td>
1530         </tr>
1531         <tr>
1532            <td class="reference"><b id="RFC2616">[RFC2616]</b></td>
1533            <td class="top">Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, “<a href="https://tools.ietf.org/html/rfc2616">Hypertext Transfer Protocol -- HTTP/1.1</a>”, RFC&nbsp;2616, June&nbsp;1999.
1534            </td>
1535         </tr>
1536         <tr>
1537            <td class="reference"><b id="RFC5226">[RFC5226]</b></td>
1538            <td class="top">Narten, T. and H. Alvestrand, “<a href="https://tools.ietf.org/html/rfc5226">Guidelines for Writing an IANA Considerations Section in RFCs</a>”, BCP&nbsp;26, RFC&nbsp;5226, May&nbsp;2008.
1539            </td>
1540         </tr>
1541      </table>
1542      <div id="internet.media.type.multipart.byteranges">
1543         <h1 id="rfc.section.A" class="np"><a href="#rfc.section.A">A.</a>&nbsp;<a href="#internet.media.type.multipart.byteranges">Internet Media Type multipart/byteranges</a></h1>
1544         <div id="rfc.section.A.p.1">
1545            <p>When a <a href="#status.206" class="smpl">206 (Partial Content)</a> response message includes the content of multiple ranges, they are transmitted as
1546               body parts in a multipart message body (<a href="#RFC2046" id="rfc.xref.RFC2046.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, <a href="https://tools.ietf.org/html/rfc2046#section-5.1">Section 5.1</a>) with the media type of "multipart/byteranges".
1547            </p>
1548         </div>
1549         <div id="rfc.section.A.p.2">
1550            <p>The multipart/byteranges media type includes one or more body parts, each with its
1551               own <a href="p2-semantics.html#header.content-type" class="smpl">Content-Type</a> and <a href="#header.content-range" class="smpl">Content-Range</a> fields. The required boundary parameter specifies the boundary string used to separate
1552               each body part.
1553            </p>
1554         </div>
1555         <div id="rfc.section.A.p.3">
1556            <p>Implementation Notes: </p>
1557            <ol>
1558               <li>Additional CRLFs might precede the first boundary string in the body.</li>
1559               <li>Although <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> permits the boundary string to be quoted, some existing implementations handle a quoted
1560                  boundary string incorrectly.
1561               </li>
1562               <li>A number of clients and servers were coded to an early draft of the byteranges specification
1563                  that used a media type of multipart/x-byteranges<span id="rfc.iref.m.1"></span><span id="rfc.iref.m.2"></span>, which is almost (but not quite) compatible with this type.
1564               </li>
1565            </ol>
1566         </div>
1567         <div id="rfc.section.A.p.4">
1568            <p>Despite the name, the "multipart/byteranges" media type is not limited to byte ranges.
1569               The following example uses an "exampleunit" range unit:
1570            </p>
1571         </div>
1572         <div id="rfc.figure.u.28"><pre class="text">HTTP/1.1 206 Partial Content
1573Date: Tue, 14 Nov 1995 06:25:24 GMT
1574Last-Modified: Tue, 14 July 04:58:08 GMT
1575Content-Length: 2331785
1576Content-Type: multipart/byteranges; boundary=THIS_STRING_SEPARATES
1577
1578--THIS_STRING_SEPARATES
1579Content-Type: video/example
1580Content-Range: exampleunit 1.2-4.3/25
1581
1582...the first range...
1583--THIS_STRING_SEPARATES
1584Content-Type: video/example
1585Content-Range: exampleunit 11.2-14.3/25
1586
1587...the second range
1588--THIS_STRING_SEPARATES--
1589</pre></div>
1590      </div>
1591      <div id="changes.from.rfc.2616">
1592         <h1 id="rfc.section.B"><a href="#rfc.section.B">B.</a>&nbsp;<a href="#changes.from.rfc.2616">Changes from RFC 2616</a></h1>
1593         <div id="rfc.section.B.p.1">
1594            <p>Servers are given more leeway in how they respond to a range request, in order to
1595               mitigate abuse by malicious (or just greedy) clients. (<a href="#header.range" id="rfc.xref.header.range.5" title="Range">Section&nbsp;3.1</a>)
1596            </p>
1597         </div>
1598         <div id="rfc.section.B.p.2">
1599            <p>A weak validator cannot be used in a <a href="#status.206" class="smpl">206</a> response. (<a href="#status.206" id="rfc.xref.status.206.2" title="206 Partial Content">Section&nbsp;4.1</a>)
1600            </p>
1601         </div>
1602         <div id="rfc.section.B.p.3">
1603            <p>The Content-Range header field only has meaning when the status code explicitly defines
1604               its use. (<a href="#header.content-range" id="rfc.xref.header.content-range.4" title="Content-Range">Section&nbsp;4.2</a>)
1605            </p>
1606         </div>
1607         <div id="rfc.section.B.p.4">
1608            <p>This specification introduces a Range Unit Registry. (<a href="#range.unit.registry" title="Range Unit Registry">Section&nbsp;5.1</a>)
1609            </p>
1610         </div>
1611         <div id="rfc.section.B.p.5">
1612            <p>multipart/byteranges can consist of a single part. (<a href="#internet.media.type.multipart.byteranges" title="Internet Media Type multipart/byteranges">Appendix&nbsp;A</a>)
1613            </p>
1614         </div>
1615      </div>
1616      <div id="imported.abnf">
1617         <h1 id="rfc.section.C"><a href="#rfc.section.C">C.</a>&nbsp;<a href="#imported.abnf">Imported ABNF</a></h1>
1618         <div id="rfc.section.C.p.1">
1619            <p>The following core rules are included by reference, as defined in <a href="https://tools.ietf.org/html/rfc5234#appendix-B.1">Appendix B.1</a> of <a href="#RFC5234" id="rfc.xref.RFC5234.2"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>: ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls), DIGIT (decimal
1620               0-9), DQUOTE (double quote), HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET
1621               (any 8-bit sequence of data), SP (space), and VCHAR (any visible US-ASCII character).
1622            </p>
1623         </div>
1624         <div id="rfc.section.C.p.2">
1625            <p>Note that all rules derived from <a href="#imported.abnf" class="smpl">token</a> are to be compared case-insensitively, like <a href="#range.units" class="smpl">range-unit</a> and <a href="#header.accept-ranges" class="smpl">acceptable-ranges</a>.
1626            </p>
1627         </div>
1628         <div id="rfc.section.C.p.3">
1629            <p>The rules below are defined in <a href="#RFC7230" id="rfc.xref.RFC7230.5"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[RFC7230]</cite></a>:
1630            </p>
1631         </div>
1632         <div id="rfc.figure.u.29"><pre class="inline">  <a href="#imported.abnf" class="smpl">OWS</a>        = &lt;OWS, see <a href="#RFC7230" id="rfc.xref.RFC7230.6"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[RFC7230]</cite></a>, <a href="p1-messaging.html#whitespace" title="Whitespace">Section 3.2.3</a>&gt;
1633  <a href="#imported.abnf" class="smpl">token</a>      = &lt;token, see <a href="#RFC7230" id="rfc.xref.RFC7230.7"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[RFC7230]</cite></a>, <a href="p1-messaging.html#field.components" title="Field Value Components">Section 3.2.6</a>&gt;
1634</pre></div>
1635         <div id="rfc.section.C.p.4">
1636            <p>The rules below are defined in other parts:</p>
1637         </div>
1638         <div id="rfc.figure.u.30"><pre class="inline">  <a href="#imported.abnf" class="smpl">HTTP-date</a>  = &lt;HTTP-date, see <a href="#RFC7231" id="rfc.xref.RFC7231.3"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content">[RFC7231]</cite></a>, <a href="p2-semantics.html#http.date" title="Date/Time Formats">Section 7.1.1.1</a>&gt;
1639  <a href="#imported.abnf" class="smpl">entity-tag</a> = &lt;entity-tag, see <a href="#RFC7232" id="rfc.xref.RFC7232.6"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests">[RFC7232]</cite></a>, <a href="p4-conditional.html#header.etag" title="ETag">Section 2.3</a>&gt;
1640</pre></div>
1641      </div>
1642      <div id="collected.abnf">
1643         <h1 id="rfc.section.D"><a href="#rfc.section.D">D.</a>&nbsp;<a href="#collected.abnf">Collected ABNF</a></h1>
1644         <div id="rfc.section.D.p.1">
1645            <p>In the collected ABNF below, list rules are expanded as per <a href="p1-messaging.html#notation" title="Syntax Notation">Section 1.2</a> of <a href="#RFC7230" id="rfc.xref.RFC7230.8"><cite title="Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing">[RFC7230]</cite></a>.
1646            </p>
1647         </div>
1648         <div id="rfc.figure.u.31"><pre class="inline"><a href="#header.accept-ranges" class="smpl">Accept-Ranges</a> = acceptable-ranges
1649
1650<a href="#header.content-range" class="smpl">Content-Range</a> = byte-content-range / other-content-range
1651
1652<a href="#imported.abnf" class="smpl">HTTP-date</a> = &lt;HTTP-date, see [RFC7231], Section 7.1.1.1&gt;
1653
1654<a href="#header.if-range" class="smpl">If-Range</a> = entity-tag / HTTP-date
1655
1656<a href="#imported.abnf" class="smpl">OWS</a> = &lt;OWS, see [RFC7230], Section 3.2.3&gt;
1657
1658<a href="#header.range" class="smpl">Range</a> = byte-ranges-specifier / other-ranges-specifier
1659
1660<a href="#header.accept-ranges" class="smpl">acceptable-ranges</a> = ( *( "," OWS ) range-unit *( OWS "," [ OWS
1661 range-unit ] ) ) / "none"
1662
1663<a href="#header.content-range" class="smpl">byte-content-range</a> = bytes-unit SP ( byte-range-resp /
1664 unsatisfied-range )
1665<a href="#header.content-range" class="smpl">byte-range</a> = first-byte-pos "-" last-byte-pos
1666<a href="#header.content-range" class="smpl">byte-range-resp</a> = byte-range "/" ( complete-length / "*" )
1667<a href="#rule.ranges-specifier" class="smpl">byte-range-set</a> = *( "," OWS ) ( byte-range-spec /
1668 suffix-byte-range-spec ) *( OWS "," [ OWS ( byte-range-spec /
1669 suffix-byte-range-spec ) ] )
1670<a href="#rule.ranges-specifier" class="smpl">byte-range-spec</a> = first-byte-pos "-" [ last-byte-pos ]
1671<a href="#rule.ranges-specifier" class="smpl">byte-ranges-specifier</a> = bytes-unit "=" byte-range-set
1672<a href="#byte.ranges" class="smpl">bytes-unit</a> = "bytes"
1673
1674<a href="#header.content-range" class="smpl">complete-length</a> = 1*DIGIT
1675
1676<a href="#imported.abnf" class="smpl">entity-tag</a> = &lt;entity-tag, see [RFC7232], Section 2.3&gt;
1677
1678<a href="#rule.ranges-specifier" class="smpl">first-byte-pos</a> = 1*DIGIT
1679
1680<a href="#rule.ranges-specifier" class="smpl">last-byte-pos</a> = 1*DIGIT
1681
1682<a href="#header.content-range" class="smpl">other-content-range</a> = other-range-unit SP other-range-resp
1683<a href="#header.content-range" class="smpl">other-range-resp</a> = *CHAR
1684<a href="#header.range" class="smpl">other-range-set</a> = 1*VCHAR
1685<a href="#range.units.other" class="smpl">other-range-unit</a> = token
1686<a href="#header.range" class="smpl">other-ranges-specifier</a> = other-range-unit "=" other-range-set
1687
1688<a href="#range.units" class="smpl">range-unit</a> = bytes-unit / other-range-unit
1689
1690<a href="#rule.ranges-specifier" class="smpl">suffix-byte-range-spec</a> = "-" suffix-length
1691<a href="#rule.ranges-specifier" class="smpl">suffix-length</a> = 1*DIGIT
1692
1693<a href="#imported.abnf" class="smpl">token</a> = &lt;token, see [RFC7230], Section 3.2.6&gt;
1694
1695<a href="#header.content-range" class="smpl">unsatisfied-range</a> = "*/" complete-length
1696</pre></div>
1697      </div>
1698      <h1 id="rfc.index"><a href="#rfc.index">Index</a></h1>
1699      <p class="noprint"><a href="#rfc.index.2">2</a> <a href="#rfc.index.4">4</a> <a href="#rfc.index.A">A</a> <a href="#rfc.index.B">B</a> <a href="#rfc.index.C">C</a> <a href="#rfc.index.G">G</a> <a href="#rfc.index.I">I</a> <a href="#rfc.index.M">M</a> <a href="#rfc.index.R">R</a>
1700      </p>
1701      <div class="print2col">
1702         <ul class="ind">
1703            <li><a id="rfc.index.2" href="#rfc.index.2"><b>2</b></a><ul>
1704                  <li>206 Partial Content (status code)&nbsp;&nbsp;<a href="#rfc.section.4.1"><b>4.1</b></a>, <a href="#rfc.xref.status.206.1">5.2</a>, <a href="#rfc.xref.status.206.2">B</a></li>
1705               </ul>
1706            </li>
1707            <li><a id="rfc.index.4" href="#rfc.index.4"><b>4</b></a><ul>
1708                  <li>416 Range Not Satisfiable (status code)&nbsp;&nbsp;<a href="#rfc.section.4.4"><b>4.4</b></a>, <a href="#rfc.xref.status.416.1">5.2</a></li>
1709               </ul>
1710            </li>
1711            <li><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul>
1712                  <li>Accept-Ranges header field&nbsp;&nbsp;<a href="#rfc.xref.header.accept-ranges.1">2</a>, <a href="#rfc.section.2.3"><b>2.3</b></a>, <a href="#rfc.xref.header.accept-ranges.2">5.1.2</a>, <a href="#rfc.xref.header.accept-ranges.3">5.3</a></li>
1713               </ul>
1714            </li>
1715            <li><a id="rfc.index.B" href="#rfc.index.B"><b>B</b></a><ul>
1716                  <li><em>BCP13</em>&nbsp;&nbsp;<a href="#rfc.xref.BCP13.1">5.4</a>, <a href="#BCP13"><b>8.2</b></a></li>
1717                  <li><em>BCP90</em>&nbsp;&nbsp;<a href="#rfc.xref.BCP90.1">5.3</a>, <a href="#BCP90"><b>8.2</b></a></li>
1718               </ul>
1719            </li>
1720            <li><a id="rfc.index.C" href="#rfc.index.C"><b>C</b></a><ul>
1721                  <li>Content-Range header field&nbsp;&nbsp;<a href="#rfc.xref.header.content-range.1">2</a>, <a href="#rfc.section.4.2"><b>4.2</b></a>, <a href="#rfc.xref.header.content-range.2">4.4</a>, <a href="#rfc.xref.header.content-range.3">5.3</a>, <a href="#rfc.xref.header.content-range.4">B</a></li>
1722               </ul>
1723            </li>
1724            <li><a id="rfc.index.G" href="#rfc.index.G"><b>G</b></a><ul>
1725                  <li><tt>Grammar</tt>&nbsp;&nbsp;
1726                     <ul>
1727                        <li><tt>Accept-Ranges</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.14"><b>2.3</b></a></li>
1728                        <li><tt>acceptable-ranges</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.15"><b>2.3</b></a></li>
1729                        <li><tt>byte-content-range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.19"><b>4.2</b></a></li>
1730                        <li><tt>byte-range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.21"><b>4.2</b></a></li>
1731                        <li><tt>byte-range-resp</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.20"><b>4.2</b></a></li>
1732                        <li><tt>byte-range-set</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.7"><b>2.1</b></a></li>
1733                        <li><tt>byte-range-spec</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.8"><b>2.1</b></a></li>
1734                        <li><tt>byte-ranges-specifier</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.6"><b>2.1</b></a></li>
1735                        <li><tt>bytes-unit</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.2">2</a>, <a href="#rfc.iref.g.4"><b>2.1</b></a></li>
1736                        <li><tt>complete-length</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.25"><b>4.2</b></a></li>
1737                        <li><tt>Content-Range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.18"><b>4.2</b></a></li>
1738                        <li><tt>first-byte-pos</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.9"><b>2.1</b></a></li>
1739                        <li><tt>If-Range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.17"><b>3.2</b></a></li>
1740                        <li><tt>last-byte-pos</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.10"><b>2.1</b></a></li>
1741                        <li><tt>other-content-range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.23"><b>4.2</b></a></li>
1742                        <li><tt>other-range-resp</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.24"><b>4.2</b></a></li>
1743                        <li><tt>other-range-unit</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.3">2</a>, <a href="#rfc.iref.g.13"><b>2.2</b></a></li>
1744                        <li><tt>Range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.16"><b>3.1</b></a></li>
1745                        <li><tt>range-unit</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.1"><b>2</b></a></li>
1746                        <li><tt>ranges-specifier</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.5"><b>2.1</b></a></li>
1747                        <li><tt>suffix-byte-range-spec</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.11"><b>2.1</b></a></li>
1748                        <li><tt>suffix-length</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.12"><b>2.1</b></a></li>
1749                        <li><tt>unsatisfied-range</tt>&nbsp;&nbsp;<a href="#rfc.iref.g.22"><b>4.2</b></a></li>
1750                     </ul>
1751                  </li>
1752               </ul>
1753            </li>
1754            <li><a id="rfc.index.I" href="#rfc.index.I"><b>I</b></a><ul>
1755                  <li>If-Range header field&nbsp;&nbsp;<a href="#rfc.xref.header.if-range.1">3.1</a>, <a href="#rfc.section.3.2"><b>3.2</b></a>, <a href="#rfc.xref.header.if-range.2">5.3</a></li>
1756               </ul>
1757            </li>
1758            <li><a id="rfc.index.M" href="#rfc.index.M"><b>M</b></a><ul>
1759                  <li>Media Type&nbsp;&nbsp;
1760                     <ul>
1761                        <li>multipart/byteranges&nbsp;&nbsp;<a href="#rfc.section.5.4.1"><b>5.4.1</b></a>, <a href="#rfc.section.A"><b>A</b></a></li>
1762                        <li>multipart/x-byteranges&nbsp;&nbsp;<a href="#rfc.iref.m.2">A</a></li>
1763                     </ul>
1764                  </li>
1765                  <li>multipart/byteranges Media Type&nbsp;&nbsp;<a href="#rfc.section.5.4.1"><b>5.4.1</b></a>, <a href="#rfc.section.A"><b>A</b></a></li>
1766                  <li>multipart/x-byteranges Media Type&nbsp;&nbsp;<a href="#rfc.iref.m.1">A</a></li>
1767               </ul>
1768            </li>
1769            <li><a id="rfc.index.R" href="#rfc.index.R"><b>R</b></a><ul>
1770                  <li>Range header field&nbsp;&nbsp;<a href="#rfc.xref.header.range.1">2</a>, <a href="#rfc.section.3.1"><b>3.1</b></a>, <a href="#rfc.xref.header.range.2">4.1</a>, <a href="#rfc.xref.header.range.3">4.4</a>, <a href="#rfc.xref.header.range.4">5.3</a>, <a href="#rfc.xref.header.range.5">B</a></li>
1771                  <li><em>RFC2046</em>&nbsp;&nbsp;<a href="#RFC2046"><b>8.1</b></a>, <a href="#rfc.xref.RFC2046.1">A</a>, <a href="#rfc.xref.RFC2046.2">A</a><ul>
1772                        <li><em>Section 5.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2046.1">A</a></li>
1773                     </ul>
1774                  </li>
1775                  <li><em>RFC2119</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2119.1">1.1</a>, <a href="#RFC2119"><b>8.1</b></a></li>
1776                  <li><em>RFC2616</em>&nbsp;&nbsp;<a href="#RFC2616"><b>8.2</b></a></li>
1777                  <li><em>RFC5226</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5226.1">5.1.1</a>, <a href="#RFC5226"><b>8.2</b></a><ul>
1778                        <li><em>Section 4.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5226.1">5.1.1</a></li>
1779                     </ul>
1780                  </li>
1781                  <li><em>RFC5234</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5234.1">1.2</a>, <a href="#RFC5234"><b>8.1</b></a>, <a href="#rfc.xref.RFC5234.2">C</a><ul>
1782                        <li><em>Appendix B.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC5234.2">C</a></li>
1783                     </ul>
1784                  </li>
1785                  <li><em>RFC7230</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7230.1">1.1</a>, <a href="#rfc.xref.RFC7230.2">1.2</a>, <a href="#rfc.xref.RFC7230.3">6</a>, <a href="#rfc.xref.RFC7230.4">7</a>, <a href="#RFC7230"><b>8.1</b></a>, <a href="#rfc.xref.RFC7230.5">C</a>, <a href="#rfc.xref.RFC7230.6">C</a>, <a href="#rfc.xref.RFC7230.7">C</a>, <a href="#rfc.xref.RFC7230.8">D</a><ul>
1786                        <li><em>Section 1.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7230.8">D</a></li>
1787                        <li><em>Section 2.5</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7230.1">1.1</a></li>
1788                        <li><em>Section 3.2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7230.6">C</a></li>
1789                        <li><em>Section 3.2.6</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7230.7">C</a></li>
1790                        <li><em>Section 7</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7230.2">1.2</a></li>
1791                        <li><em>Section 10</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7230.4">7</a></li>
1792                     </ul>
1793                  </li>
1794                  <li><em>RFC7231</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7231.1">2.1</a>, <a href="#rfc.xref.RFC7231.2">6</a>, <a href="#RFC7231"><b>8.1</b></a>, <a href="#rfc.xref.RFC7231.3">C</a><ul>
1795                        <li><em>Section 3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7231.1">2.1</a></li>
1796                        <li><em>Section 7.1.1.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7231.3">C</a></li>
1797                     </ul>
1798                  </li>
1799                  <li><em>RFC7232</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7232.1">3.1</a>, <a href="#rfc.xref.RFC7232.2">3.2</a>, <a href="#rfc.xref.RFC7232.3">3.2</a>, <a href="#rfc.xref.RFC7232.4">3.2</a>, <a href="#rfc.xref.RFC7232.5">4.3</a>, <a href="#RFC7232"><b>8.1</b></a>, <a href="#rfc.xref.RFC7232.6">C</a><ul>
1800                        <li><em>Section 2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7232.5">4.3</a></li>
1801                        <li><em>Section 2.2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7232.2">3.2</a>, <a href="#rfc.xref.RFC7232.4">3.2</a></li>
1802                        <li><em>Section 2.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7232.6">C</a></li>
1803                        <li><em>Section 2.3.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7232.3">3.2</a></li>
1804                     </ul>
1805                  </li>
1806                  <li><em>RFC7234</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7234.1">4.1</a>, <a href="#RFC7234"><b>8.1</b></a><ul>
1807                        <li><em>Section 4.2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC7234.1">4.1</a></li>
1808                     </ul>
1809                  </li>
1810               </ul>
1811            </li>
1812         </ul>
1813      </div>
1814      <div class="avoidbreakinside">
1815         <h1 id="rfc.authors"><a href="#rfc.authors">Authors' Addresses</a></h1>
1816         <p><b>Roy T. Fielding</b>
1817            (editor)
1818            <br>Adobe Systems Incorporated<br>345 Park Ave<br>San Jose, CA&nbsp;95110<br>USA<br>Email: fielding@gbiv.com<br>URI: <a href="http://roy.gbiv.com/">http://roy.gbiv.com/</a></p>
1819         <p><b>Yves Lafon</b>
1820            (editor)
1821            <br>World Wide Web Consortium<br>W3C / ERCIM<br>2004, rte des Lucioles<br>Sophia-Antipolis, AM&nbsp;06902<br>France<br>Email: ylafon@w3.org<br>URI: <a href="http://www.raubacapeu.net/people/yves/">http://www.raubacapeu.net/people/yves/</a></p>
1822         <p><b>Julian F. Reschke</b>
1823            (editor)
1824            <br>greenbytes GmbH<br>Hafenweg 16<br>Muenster, NW&nbsp;48155<br>Germany<br>Email: julian.reschke@greenbytes.de<br>URI: <a href="http://greenbytes.de/tech/webdav/">http://greenbytes.de/tech/webdav/</a></p>
1825      </div>
1826   </body>
1827</html>
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