mpeg-audio-byte-stream-format.html

<!DOCTYPE html>
<html lang="en" dir="ltr" typeof="bibo:Document " prefix="bibo: http://purl.org/ontology/bibo/ w3p: http://www.w3.org/2001/02pd/rec54#">
<head><meta lang="" property="dc:language" content="en">
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>MPEG Audio Byte Stream Format</title>
    
    
    

    
    <!-- script to register bugs -->
    <!-- Disabled unless/until it supports GitHub issues.
    <script src="https://w3c.github.io/webcomponents/assets/scripts/bug-assist.js"></script>
    <meta name="bug.short_desc" content="[MSE] ">
    <meta name="bug.product" content="HTML WG">
    <meta name="bug.component" content="Media Source Extensions">
    -->

    <style>/* --- ISSUES/NOTES --- */
div.issue-title, div.note-title , div.ednote-title, div.warning-title {
    padding-right:  1em;
    min-width: 7.5em;
    color: #b9ab2d;
}
div.issue-title { color: #e05252; }
div.note-title, div.ednote-title { color: #2b2; }
div.warning-title { color: #f22; }
div.issue-title span, div.note-title span, div.ednote-title span, div.warning-title span {
    text-transform: uppercase;
}
div.note, div.issue, div.ednote, div.warning {
    margin-top: 1em;
    margin-bottom: 1em;
}
.note > p:first-child, .ednote > p:first-child, .issue > p:first-child, .warning > p:first-child { margin-top: 0 }
.issue, .note, .ednote, .warning {
    padding: .5em;
    border-left-width: .5em;
    border-left-style: solid;
}
div.issue, div.note , div.ednote,  div.warning {
    padding: 1em 1.2em 0.5em;
    margin: 1em 0;
    position: relative;
    clear: both;
}
span.note, span.ednote, span.issue, span.warning { padding: .1em .5em .15em; }

.issue {
    border-color: #e05252;
    background: #fbe9e9;
}
.note, .ednote {
    border-color: #52e052;
    background: #e9fbe9;
}

.warning {
    border-color: #f11;
    border-right-width: .2em;
    border-top-width: .2em;
    border-bottom-width: .2em;
    border-style: solid;
    background: #fbe9e9;
}

.warning-title:before{
    content: "⚠"; /*U+26A0 WARNING SIGN*/
    font-size: 3em;
    float: left;
    height: 100%;
    padding-right: .3em;
    vertical-align: top;
    margin-top: -0.5em;
}

li.task-list-item {
    list-style: none;
}

input.task-list-item-checkbox {
    margin: 0 0.35em 0.25em -1.6em;
    vertical-align: middle;
}
</style><link rel="stylesheet" href="mse.css">

  <style>/*****************************************************************
 * ReSpec 3 CSS
 * Robin Berjon - http://berjon.com/
 *****************************************************************/

/* --- INLINES --- */
em.rfc2119 { 
    text-transform:     lowercase;
    font-variant:       small-caps;
    font-style:         normal;
    color:              #900;
}

h1 acronym, h2 acronym, h3 acronym, h4 acronym, h5 acronym, h6 acronym, a acronym,
h1 abbr, h2 abbr, h3 abbr, h4 abbr, h5 abbr, h6 abbr, a abbr {
    border: none;
}

dfn {
    font-weight:    bold;
}

a.internalDFN {
    color:  inherit;
    border-bottom:  1px solid #99c;
    text-decoration:    none;
}

a.externalDFN {
    color:  inherit;
    border-bottom:  1px dotted #ccc;
    text-decoration:    none;
}

a.bibref {
    text-decoration:    none;
}

cite .bibref {
    font-style: normal;
}

code {
    color:  #C83500;
}

/* --- TOC --- */
.toc a, .tof a {
    text-decoration:    none;
}

a .secno, a .figno {
    color:  #000;
}

ul.tof, ol.tof {
    list-style: none outside none;
}

.caption {
    margin-top: 0.5em;
    font-style:   italic;
}

/* --- TABLE --- */
table.simple {
    border-spacing: 0;
    border-collapse:    collapse;
    border-bottom:  3px solid #005a9c;
}

.simple th {
    background: #005a9c;
    color:  #fff;
    padding:    3px 5px;
    text-align: left;
}

.simple th[scope="row"] {
    background: inherit;
    color:  inherit;
    border-top: 1px solid #ddd;
}

.simple td {
    padding:    3px 10px;
    border-top: 1px solid #ddd;
}

.simple tr:nth-child(even) {
    background: #f0f6ff;
}

/* --- DL --- */
.section dd > p:first-child {
    margin-top: 0;
}

.section dd > p:last-child {
    margin-bottom: 0;
}

.section dd {
    margin-bottom:  1em;
}

.section dl.attrs dd, .section dl.eldef dd {
    margin-bottom:  0;
}

@media print {
    .removeOnSave {
        display: none;
    }
}
</style><link rel="stylesheet" href="https://www.w3.org/StyleSheets/TR/W3C-ED"><!--[if lt IE 9]><script src='https://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]--><script id="initialUserConfig" type="application/json">{
  "specStatus": "ED",
  "shortName": "media-source",
  "edDraftURI": "https://w3c.github.io/media-source/mpeg-audio-byte-stream-format.html",
  "prevVersion": "http://www.w3.org/2013/12/byte-stream-format-registry/mpeg-audio-byte-stream-format.html",
  "editors": [
    {
      "name": "Dale Curtis",
      "url": "",
      "company": "Google Inc.",
      "companyURL": "http://www.google.com/"
    },
    {
      "name": "Matthew Wolenetz",
      "url": "",
      "company": "Google Inc.",
      "companyURL": "http://www.google.com/"
    },
    {
      "name": "Aaron Colwell (until April 2015)",
      "url": "",
      "company": "Google Inc.",
      "companyURL": "http://www.google.com/"
    }
  ],
  "mseDefGroupName": "mpeg-byte-stream-format",
  "mseUnusedGroupNameExcludeList": [
    "media-source"
  ],
  "mseContributors": [],
  "wg": "HTML Media Extensions Working Group",
  "wgURI": "http://www.w3.org/html/wg/",
  "wgPublicList": "public-html-media",
  "wgPatentURI": "http://www.w3.org/2004/01/pp-impl/40318/status",
  "noIDLIn": true,
  "scheme": "https",
  "otherLinks": [
    {
      "key": "Repository",
      "data": [
        {
          "value": "We are on GitHub",
          "href": "https://github.com/w3c/media-source/"
        },
        {
          "value": "File a bug",
          "href": "https://github.com/w3c/media-source/issues"
        },
        {
          "value": "Commit history",
          "href": "https://github.com/w3c/media-source/commits/gh-pages/mpeg-audio-byte-stream-format-respec.html"
        }
      ]
    },
    {
      "key": "Mailing list",
      "data": [
        {
          "value": "public-html-media@w3.org",
          "href": "https://lists.w3.org/Archives/Public/public-html-media/"
        }
      ]
    }
  ],
  "preProcess": [
    null,
    null
  ],
  "definitionMap": {
    "mpeg audio frame": [
      "mpeg-audio-frame"
    ],
    "icecast header": [
      "icecast-header"
    ]
  },
  "postProcess": [
    null
  ]
}</script></head>
  <body class="h-entry" role="document" id="respecDocument"><div class="head" role="contentinfo" id="respecHeader">
  <p>
      
        
            <a class="logo" href="http://www.w3.org/"><img width="72" height="48" src="https://www.w3.org/Icons/w3c_home" alt="W3C"></a>
            
            
        
      
  </p>
  <h1 class="title p-name" id="title" property="dcterms:title">MPEG Audio Byte Stream Format</h1>
  
  <h2 id="w3c-editor-s-draft-10-august-2016"><abbr title="World Wide Web Consortium">W3C</abbr> Editor's Draft <time property="dcterms:issued" class="dt-published" datetime="2016-08-10">10 August 2016</time></h2>
  <dl>
    
      <dt>This version:</dt>
      <dd><a class="u-url" href="https://w3c.github.io/media-source/mpeg-audio-byte-stream-format.html">https://w3c.github.io/media-source/mpeg-audio-byte-stream-format.html</a></dd>
      <dt>Latest published version:</dt>
      <dd><a href="http://www.w3.org/TR/media-source/">http://www.w3.org/TR/media-source/</a></dd>
    
    
      <dt>Latest editor's draft:</dt>
      <dd><a href="https://w3c.github.io/media-source/mpeg-audio-byte-stream-format.html">https://w3c.github.io/media-source/mpeg-audio-byte-stream-format.html</a></dd>
    
    
    
    
    
      
    
    
    
    <dt>Editors:</dt>
    <dd class="p-author h-card vcard" property="bibo:editor" resource="_:editor0"><span property="rdf:first" typeof="foaf:Person"><span property="foaf:name" class="p-name fn">Dale Curtis</span>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.google.com/">Google Inc.</a></span>
<span property="rdf:rest" resource="_:editor1"></span>
</dd>
<dd class="p-author h-card vcard" resource="_:editor1"><span property="rdf:first" typeof="foaf:Person"><span property="foaf:name" class="p-name fn">Matthew Wolenetz</span>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.google.com/">Google Inc.</a></span>
<span property="rdf:rest" resource="_:editor2"></span>
</dd>
<dd class="p-author h-card vcard" resource="_:editor2"><span property="rdf:first" typeof="foaf:Person"><span property="foaf:name" class="p-name fn">Aaron Colwell (until April 2015)</span>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.google.com/">Google Inc.</a></span>
<span property="rdf:rest" resource="rdf:nil"></span>
</dd>

    
    
      
        
          <dt>Repository:</dt>
          
             
                
                  <dd>
                    <a href="https://github.com/w3c/media-source/">
                      We are on GitHub
                    </a>
                  </dd>
                
             
                
                  <dd>
                    <a href="https://github.com/w3c/media-source/issues">
                      File a bug
                    </a>
                  </dd>
                
             
                
                  <dd>
                    <a href="https://github.com/w3c/media-source/commits/gh-pages/mpeg-audio-byte-stream-format-respec.html">
                      Commit history
                    </a>
                  </dd>
                
             
          
        
      
        
          <dt>Mailing list:</dt>
          
             
                
                  <dd>
                    <a href="https://lists.w3.org/Archives/Public/public-html-media/">
                      public-html-media@w3.org
                    </a>
                  </dd>
                
             
          
        
      
    
  </dl>
  
  
  
  
    
      <p class="copyright">
        <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> ©
        2016
        
        <a href="http://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup>
        (<a href="http://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>,
        <a href="http://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>,
        <a href="http://www.keio.ac.jp/">Keio</a>, <a href="http://ev.buaa.edu.cn/">Beihang</a>). 
        
        <abbr title="World Wide Web Consortium">W3C</abbr> <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
        <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and
        
          
            <a rel="license" href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a>
          
        
        rules apply.
      </p>
    
  
  <hr title="Separator for header">
</div>
    <section id="abstract" class="introductory" property="dc:abstract"><h2 id="h-abstract" resource="#h-abstract"><span property="xhv:role" resource="xhv:heading">Abstract</span></h2><p>
      This specification defines a <a href="http://www.w3.org/TR/media-source/">Media Source Extensions</a> byte stream format specification based on MPEG audio streams.
    </p></section><section id="sotd" class="introductory"><h2 id="h-sotd" resource="#h-sotd"><span property="xhv:role" resource="xhv:heading">Status of This Document</span></h2>
  
    
      
        <p>
          <em>This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current <abbr title="World Wide Web Consortium">W3C</abbr> publications and the latest revision of this technical report can be found in the <a href="http://www.w3.org/TR/"><abbr title="World Wide Web Consortium">W3C</abbr> technical reports index</a> at http://www.w3.org/TR/.</em>
        </p>
        
          
          
      <p>The working group maintains <a href="https://github.com/w3c/media-source/issues">a list of all bug reports that the editors have not yet tried to address</a>; there may also be open bugs in the <a href="http://w3.org/brief/Mjcw">previous bug tracker</a>.</p>
      <p>Implementors should be aware that this specification is not stable. <strong>Implementors who are not taking part in the discussions are likely to find the specification changing out from under them in incompatible ways.</strong> Vendors interested in implementing this specification before it eventually reaches the Candidate Recommendation stage should join the mailing list mentioned below and take part in the discussions.</p>
    
          
          
          <p>
            This document was published by the <a href="http://www.w3.org/html/wg/">HTML Media Extensions Working Group</a> as an Editor's Draft.
            
            
              If you wish to make comments regarding this document, please send them to
              <a href="mailto:public-html-media@w3.org">public-html-media@w3.org</a>
              (<a href="mailto:public-html-media-request@w3.org?subject=subscribe">subscribe</a>,
              <a href="http://lists.w3.org/Archives/Public/public-html-media/">archives</a>).
            
            
            
            
            
              
              All comments are welcome.
              
            
          </p>
          
          
          
          
            <p>
              Publication as an Editor's Draft does not imply endorsement by the <abbr title="World Wide Web Consortium">W3C</abbr>
              Membership. This is a draft document and may be updated, replaced or obsoleted by other
              documents at any time. It is inappropriate to cite this document as other than work in
              progress.
            </p>
          
          
          
          <p>
            
              This document was produced by
              
              a group
               operating under the
              <a id="sotd_patent" property="w3p:patentRules" href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February 2004 <abbr title="World Wide Web Consortium">W3C</abbr> Patent
              Policy</a>.
            
            
            
              
                <abbr title="World Wide Web Consortium">W3C</abbr> maintains a <a href="http://www.w3.org/2004/01/pp-impl/40318/status" rel="disclosure">public list of any patent
                disclosures</a>
              
              made in connection with the deliverables of
              
              the group; that page also includes
              
              instructions for disclosing a patent. An individual who has actual knowledge of a patent
              which the individual believes contains
              <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential
              Claim(s)</a> must disclose the information in accordance with
              <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
              6 of the <abbr title="World Wide Web Consortium">W3C</abbr> Patent Policy</a>.
            
            
          </p>
          
            <p>This document is governed by the <a id="w3c_process_revision" href="http://www.w3.org/2015/Process-20150901/">1 September 2015 <abbr title="World Wide Web Consortium">W3C</abbr> Process Document</a>.
            </p>
          
          
        
      
    
  
</section><section id="toc"><h2 class="introductory" id="h-toc" resource="#h-toc"><span property="xhv:role" resource="xhv:heading">Table of Contents</span></h2><ul class="toc" role="directory"><li class="tocline"><a href="#introduction" class="tocxref"><span class="secno">1. </span>Introduction</a></li><li class="tocline"><a href="#mime-types" class="tocxref"><span class="secno">2. </span>MIME-types</a></li><li class="tocline"><a href="#mpeg-audio-frames" class="tocxref"><span class="secno">3. </span>MPEG Audio Frames</a></li><li class="tocline"><a href="#mpeg-metadata" class="tocxref"><span class="secno">4. </span>Metadata Frames</a><ul class="toc"><li class="tocline"><a href="#icecast" class="tocxref"><span class="secno">4.1 </span>Icecast headers</a></li></ul></li><li class="tocline"><a href="#mpeg-segments" class="tocxref"><span class="secno">5. </span>Segment Definitions</a></li><li class="tocline"><a href="#conformance" class="tocxref"><span class="secno">6. </span>Conformance</a></li><li class="tocline"><a href="#references" class="tocxref"><span class="secno">A. </span>References</a><ul class="toc"><li class="tocline"><a href="#normative-references" class="tocxref"><span class="secno">A.1 </span>Normative references</a></li></ul></li></ul></section>

    

    <section id="introduction" typeof="bibo:Chapter" resource="#introduction" property="bibo:hasPart">
      <!--OddPage--><h2 id="h-introduction" resource="#h-introduction"><span property="xhv:role" resource="xhv:heading"><span class="secno">1. </span>Introduction</span></h2>
      <p>This specification defines segment formats for implementations that choose to support MPEG audio streams specified in <a href="http://www.iso.org/iso/catalogue_detail.htm?csnumber=22412">ISO/IEC 11172-3:1993</a>, <a href="http://www.iso.org/iso/catalogue_detail.htm?csnumber=26797">ISO/IEC 13818-3:1998</a>, and <a href="http://www.iso.org/iso/catalogue_detail.htm?csnumber=53943">ISO/IEC 14496-3:2009</a>.</p>
      <p>It defines the <a href="#mime-types">MIME-types</a> used to signal codecs, and provides the necessary format specific definitions for <a href="index.html#init-segment">initialization segments</a>, <a href="index.html#media-segment">media segments</a>, and <a href="index.html#random-access-point">random access points</a> required by the <a href="index.html#byte-stream-formats">byte stream formats section</a> of the Media Source Extensions spec. It also defines extra behaviors and state that only apply to this byte stream format.</p>
    </section>

    <section id="mime-types" typeof="bibo:Chapter" resource="#mime-types" property="bibo:hasPart">
      <!--OddPage--><h2 id="h-mime-types" resource="#h-mime-types"><span property="xhv:role" resource="xhv:heading"><span class="secno">2. </span>MIME-types</span></h2>
      <p>This section specifies the MIME-types that may be passed to <code><a href="index.html#dom-mediasource-istypesupported">isTypeSupported()</a></code> or <code><a href="index.html#dom-mediasource-addsourcebuffer">addSourceBuffer()</a></code> for byte streams that conform to this specification.</p>
      <ul>
        <li>"audio/aac" for sequences of ADTS frames, as specified in <a href="http://www.iso.org/iso/catalogue_detail.htm?csnumber=53943">ISO/IEC 14496-3:2009</a>.</li>
        <li>"audio/mpeg" for MPEG-1/2/2.5 Layer I/II/III streams, as specified in <a href="http://tools.ietf.org/html/rfc3003">RFC 3003</a>.</li>
      </ul>
      <p>The "codecs" MIME-type parameter <em class="rfc2119" title="MUST NOT">MUST NOT</em> be used with these MIME-types.</p>
    </section>

    <section id="mpeg-audio-frames" typeof="bibo:Chapter" resource="#mpeg-audio-frames" property="bibo:hasPart">
      <!--OddPage--><h2 id="h-mpeg-audio-frames" resource="#h-mpeg-audio-frames"><span property="xhv:role" resource="xhv:heading"><span class="secno">3. </span>MPEG Audio Frames</span></h2>
      <p>The format of an <dfn id="mpeg-audio-frame" data-dfn-type="dfn">MPEG Audio Frame</dfn> depends on the <a href="#mime-types">MIME-type</a> used.</p>
      <ul>
        <li>If the "audio/aac" MIME-type is used, an MPEG Audio Frame is a sequence of bytes that conform to the adts_frame() syntax specified in Table 1.A.5 of <a href="http://www.iso.org/iso/catalogue_detail.htm?csnumber=53943">ISO/IEC 14496-3:2009</a>.</li>
        <li>If the "audio/mpeg" MIME-type is used, an MPEG Audio Frame is a sequence of bytes that conform to the frame() syntax element specified in Section 2.4.1.2 of <a href="http://www.iso.org/iso/catalogue_detail.htm?csnumber=22412">ISO/IEC 11172-3:1993</a> or the corresponding definition in <a href="http://www.iso.org/iso/catalogue_detail.htm?csnumber=26797">ISO/IEC 13818-3:1998</a>.</li>
      </ul>
    </section>

    <section id="mpeg-metadata" typeof="bibo:Chapter" resource="#mpeg-metadata" property="bibo:hasPart">
      <!--OddPage--><h2 id="h-mpeg-metadata" resource="#h-mpeg-metadata"><span property="xhv:role" resource="xhv:heading"><span class="secno">4. </span>Metadata Frames</span></h2>
      <p>Since <a href="http://id3.org/ID3v1">ID3v1</a>, <a href="http://id3.org/id3v2.3.0">ID3v2</a> metadata frames, and <a href="#icecast-header">Icecast headers</a> are common in existing MPEG audio streams, implementations <em class="rfc2119" title="SHOULD">SHOULD</em> gracefully handle such frames. Zero or more of these metadata frames are allowed to occur before, after, or between <a href="#mpeg-audio-frame">MPEG Audio Frames</a>. Minimal implementations <em class="rfc2119" title="MUST">MUST</em> accept, consume, and ignore these frames. More advanced implementations <em class="rfc2119" title="MAY">MAY</em> choose to expose the metadata information via an inband <code><a href="https://www.w3.org/TR/html51/semantics-embedded-content.html#texttrack-texttrack">TextTrack</a></code> or some other mechanism.</p>

      <section id="icecast" typeof="bibo:Chapter" resource="#icecast" property="bibo:hasPart">
        <h3 id="h-icecast" resource="#h-icecast"><span property="xhv:role" resource="xhv:heading"><span class="secno">4.1 </span>Icecast headers</span></h3>
        <p>There is no normative spec for <a href="http://en.wikipedia.org/wiki/Icecast">Icecast</a>/<a href="http://en.wikipedia.org/wiki/SHOUTcast">SHOUTcast</a> headers, just <a href="http://forums.radiotoolbox.com/viewtopic.php?t=74">examples</a>. For the purpose of this specification, an <dfn id="icecast-header" data-dfn-type="dfn">Icecast header</dfn> is defined as beginning with the 4 character sequence "ICY&nbsp;"(U+0049 I, U+0043 C, U+0059 Y, U+0020 SPACE) and ending with a pair of carriage-return line-feed sequences (U+000D CARRIAGE RETURN, U+000A LINE FEED, U+000D CARRIAGE RETURN, U+000A LINE FEED).</p>
        <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note1"><span>Note</span></div><p class="">Icecast headers are allowed in the byte streams because some Icecast and SHOUTcast
          servers return a status line that looks like "ICY OK 200" instead of a standard HTTP status line.
          User-agent network stacks typically interpret this as an HTTP 0.9 response and include the
          header in the response body. Allowing these headers to appear provides a simple way to
          interoperate with these servers.</p></div>
      </section>
    </section>

    <section id="mpeg-segments" typeof="bibo:Chapter" resource="#mpeg-segments" property="bibo:hasPart">
      <!--OddPage--><h2 id="h-mpeg-segments" resource="#h-mpeg-segments"><span property="xhv:role" resource="xhv:heading"><span class="secno">5. </span>Segment Definitions</span></h2>
      <p>The MPEG audio byte stream is a combination of one or more <a href="#mpeg-audio-frame">MPEG Audio Frames</a> and zero or more <a href="#mpeg-metadata">Metadata Frames</a>.</p>
      <ul>
        <li>Every <a href="#mpeg-audio-frame">MPEG Audio Frame</a> is a <a href="index.html#random-access-point">random access point</a>.</li>
        <li>Every <a href="#mpeg-audio-frame">MPEG Audio Frame</a> header is an <a href="index.html#init-segment">initialization segment</a>.</li>
        <li>The coded audio in each <a href="#mpeg-audio-frame">MPEG Audio Frame</a> is a <a href="index.html#media-segment">media segment</a>.</li>
      </ul>
    </section>

    <section id="conformance" typeof="bibo:Chapter" resource="#conformance" property="bibo:hasPart"><!--OddPage--><h2 id="h-conformance" resource="#h-conformance"><span property="xhv:role" resource="xhv:heading"><span class="secno">6. </span>Conformance</span></h2>
<p>
  As well as sections marked as non-normative, all authoring guidelines, diagrams, examples,
  and notes in this specification are non-normative. Everything else in this specification is
  normative.
</p>
<p id="respecRFC2119">The key words <em class="rfc2119" title="MAY">MAY</em>, <em class="rfc2119" title="MUST">MUST</em>, <em class="rfc2119" title="MUST NOT">MUST NOT</em>, and <em class="rfc2119" title="SHOULD">SHOULD</em> are 
  to be interpreted as described in [<cite><a class="bibref" href="#bib-RFC2119">RFC2119</a></cite>].
</p>
</section>

<!--     <section id="acknowledgements">
      <h2>Acknowledgments</h2>
      The editors would like to thank <a def-id="contributors"></a> for their contributions to this specification.
    </section> -->
  

<section id="references" class="appendix" typeof="bibo:Chapter" resource="#references" property="bibo:hasPart"><!--OddPage--><h2 id="h-references" resource="#h-references"><span property="xhv:role" resource="xhv:heading"><span class="secno">A. </span>References</span></h2><section id="normative-references" typeof="bibo:Chapter" resource="#normative-references" property="bibo:hasPart"><h3 id="h-normative-references" resource="#h-normative-references"><span property="xhv:role" resource="xhv:heading"><span class="secno">A.1 </span>Normative references</span></h3><dl class="bibliography" resource=""><dt id="bib-RFC2119">[RFC2119]</dt><dd>S. Bradner. <a href="https://tools.ietf.org/html/rfc2119" property="dc:requires"><cite>Key words for use in RFCs to Indicate Requirement Levels</cite></a>. March 1997. Best Current Practice. URL: <a href="https://tools.ietf.org/html/rfc2119" property="dc:requires">https://tools.ietf.org/html/rfc2119</a>
</dd></dl></section></section></body></html>