CINXE.COM

<!DOCTYPE html> <html lang="en" dir="ltr" typeof="bibo:Document w3p:REC" prefix="bibo: http://purl.org/ontology/bibo/ w3p: http://www.w3.org/2001/02pd/rec54#"> <head><meta property="dc:language" content="en" lang=""> <title>RDFa Lite 1.1 - Second Edition</title> <meta http-equiv="Content-Type" content="text/html;charset=utf-8">  <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><style>/* --- EXAMPLES --- */ div.example-title { min-width: 7.5em; color: #b9ab2d; } div.example-title span { text-transform: uppercase; } aside.example, div.example, div.illegal-example { padding: 0.5em; margin: 1em 0; position: relative; clear: both; } div.illegal-example { color: red } div.illegal-example p { color: black } aside.example, div.example { padding: .5em; border-left-width: .5em; border-left-style: solid; border-color: #e0cb52; background: #fcfaee; } aside.example div.example { border-left-width: .1em; border-color: #999; background: #fff; } aside.example div.example div.example-title { color: #999; } </style><link href="https://www.w3.org/StyleSheets/TR/W3C-REC" rel="stylesheet"></head> <body id="respecDocument" role="document" class="h-entry"><div id="respecHeader" role="contentinfo" class="head"> <p> <a href="https://www.w3.org/"><img src="https://www.w3.org/Icons/w3c_home" alt="W3C" height="48" width="72"></a> </p> <h1 class="title p-name" id="title" property="dcterms:title">RDFa Lite 1.1 - Second Edition</h1> <h2 id="w3c-recommendation-17-march-2015"><abbr title="World Wide Web Consortium">W3C</abbr> Recommendation <time property="dcterms:issued" class="dt-published" datetime="2015-03-17">17 March 2015</time></h2> <dl> <dt>This version:</dt> <dd><a class="u-url" href="https://www.w3.org/TR/2015/REC-rdfa-lite-20150317/">http://www.w3.org/TR/2015/REC-rdfa-lite-20150317/</a></dd> <dt>Latest published version:</dt> <dd><a href="https://www.w3.org/TR/rdfa-lite/">http://www.w3.org/TR/rdfa-lite/</a></dd> <dt>Implementation report:</dt> <dd><a href="https://www.w3.org/2010/02/rdfa/wiki/CR-ImplementationReport">http://www.w3.org/2010/02/rdfa/wiki/CR-ImplementationReport</a></dd> <dt>Previous version:</dt> <dd><a rel="dcterms:replaces" href="https://www.w3.org/TR/2014/PER-rdfa-lite-20141216/">http://www.w3.org/TR/2014/PER-rdfa-lite-20141216/</a></dd> <dt>Previous Recommendation:</dt> <dd><a rel="dcterms:replaces" href="https://www.w3.org/TR/2012/REC-rdfa-lite-20120607/">http://www.w3.org/TR/2012/REC-rdfa-lite-20120607/</a></dd> <dt>Editor:</dt> <dd class="p-author h-card vcard" property="bibo:editor" resource="_:editor0"><span property="rdf:first" typeof="foaf:Person"><meta property="foaf:name" content="Manu Sporny"><a class="u-url url p-name fn" property="foaf:homepage" href="http://digitalbazaar.com/">Manu Sporny</a>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://digitalbazaar.com/">Digital Bazaar, Inc.</a></span> <span property="rdf:rest" resource="rdf:nil"></span> </dd> </dl> <p> Please check the <a href="https://www.w3.org/2015/rdfa1.1-errata"><strong>errata</strong></a> for any errors or issues reported since publication. </p> <p> This document is also available in this non-normative format: <a rel="alternate" href="diff-20150317.html">diff to previous version</a> </p> <p> The English version of this specification is the only normative version. Non-normative <a href="https://www.w3.org/Consortium/Translation/">translations</a> may also be available. </p> <p class="copyright"> <a href="https://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 2015 <a href="https://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="https://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="https://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="https://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply. </p> <hr> </div> <section property="dc:abstract" class="introductory" id="abstract"><h2 resource="#h-abstract" id="h-abstract"><span property="xhv:role" resource="xhv:heading">Abstract</span></h2> <p> RDFa Lite is a minimal subset of RDFa, the Resource Description Framework in attributes, consisting of a few attributes that may be used to express machine-readable data in Web documents like HTML, SVG, and XML. While it is not a complete solution for advanced data markup tasks, it does work for most day-to-day needs and can be learned by most Web authors in a day. </p> </section><section id="sotd" class="introductory"><h2 resource="#h-sotd" id="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="https://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>This is an Editorial Revision of the <a href="https://www.w3.org/TR/2012/REC-rdfa-lite-20120607/">Recommendation published on the 7th of June, 2012</a>. See <a href="#changes">the separate section</a> for the changes.</p> <p><abbr title="World Wide Web Consortium">W3C</abbr> is expected to address <a href="https://www.w3.org/2015/rdfa1.1-errata">errata</a> in a future Edited Recommendation of RDFa 1.1 Lite. The current <a href="#conformance">Document Conformance section</a> is not explicit about some conformance expectations that appear in non-normative sections, specifically to require RDFa Lite attributes to be conformant to RDFa Core 1.1 and to pre-define a number of prefixes per RDFa Core 1.1. </p> <p> This document is the culmination of a series of discussions between the World Wide Web Consortium, including the RDFa Working Group, the Vocabularies Community Group, the HTML Working Group, and the sponsors of the <a href="http://schema.org">schema.org</a> initiative, including Google, Yahoo!, Microsoft, and Yandex. It has received review from representatives in these organizations and enjoys consensus at this point in time. There were no changes made during the Proposed Recommendation period. The <a href="https://www.w3.org/2010/02/rdfa/wiki/CR-ImplementationReport">implementation report</a> used by the director to transition to Recommendation has been made available.</p> <p> This document was published by the <a href="https://www.w3.org/2010/02/rdfa/">RDFa Working Group</a> as a Recommendation. If you wish to make comments regarding this document, please send them to <a href="mailto:public-rdfa@w3.org">public-rdfa@w3.org</a> (<a href="mailto:public-rdfa-request@w3.org?subject=subscribe">subscribe</a>, <a href="http://lists.w3.org/Archives/Public/public-rdfa/">archives</a>). All comments are welcome. </p> <p> Please see the Working Group's <a href="https://www.w3.org/2010/02/rdfa/wiki/CR-ImplementationReport">implementation report</a>. </p> <p> This document has been reviewed by <abbr title="World Wide Web Consortium">W3C</abbr> Members, by software developers, and by other <abbr title="World Wide Web Consortium">W3C</abbr> groups and interested parties, and is endorsed by the Director as a <abbr title="World Wide Web Consortium">W3C</abbr> Recommendation. It is a stable document and may be used as reference material or cited from another document. <abbr title="World Wide Web Consortium">W3C</abbr>'s role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment. This enhances the functionality and interoperability of the Web. </p> <p> This document was produced by a group operating under the <a id="sotd_patent" property="w3p:patentRules" href="https://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="https://www.w3.org/2004/01/pp-impl/44350/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="https://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential Claim(s)</a> must disclose the information in accordance with <a href="https://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="https://www.w3.org/2005/10/Process-20051014/">14 October 2005 <abbr title="World Wide Web Consortium">W3C</abbr> Process Document</a>. </p> </section><section id="toc"><h2 resource="#h-toc" id="h-toc" class="introductory"><span property="xhv:role" resource="xhv:heading">Table of Contents</span></h2><ul id="respecContents" role="directory" class="toc"><li class="tocline"><a class="tocxref" href="#introduction"><span class="secno">1. </span>Introduction</a></li><li class="tocline"><a class="tocxref" href="#the-attributes"><span class="secno">2. </span>The Attributes</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#vocab-typeof-and-property"><span class="secno">2.1 </span>vocab, typeof, and property</a></li><li class="tocline"><a class="tocxref" href="#resource"><span class="secno">2.2 </span>resource</a></li><li class="tocline"><a class="tocxref" href="#prefix"><span class="secno">2.3 </span>prefix</a></li></ul></li><li class="tocline"><a class="tocxref" href="#conformance"><span class="secno">3. </span>Conformance</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#document-conformance"><span class="secno">3.1 </span>Document Conformance</a></li></ul></li><li class="tocline"><a class="tocxref" href="#change-history-since-the-last-published-recommentation"><span class="secno">4. </span>Change History Since the Last Published Recommentation</a></li><li class="tocline"><a class="tocxref" href="#references"><span class="secno">A. </span>References</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#normative-references"><span class="secno">A.1 </span>Normative references</a></li><li class="tocline"><a class="tocxref" href="#informative-references"><span class="secno">A.2 </span>Informative references</a></li></ul></li></ul></section> <section property="bibo:hasPart" resource="#introduction" typeof="bibo:Chapter" id="introduction" class="informative"> <h2 resource="#h-introduction" id="h-introduction"><span property="xhv:role" resource="xhv:heading"><span class="secno">1. </span>Introduction</span></h2><p><em>This section is non-normative.</em></p> <p> The full RDFa syntax [<cite><a href="#bib-rdfa-core" class="bibref">rdfa-core</a></cite>] provides a number of basic and advanced features that enable authors to express fairly complex structured data, such as relationships among people, places, and events in an HTML or XML document. Some of these advanced features may make it difficult for authors, who may not be experts in structured data, to use RDFa. This lighter version of RDFa is a gentler introduction to the world of structured data, intended for authors that want to express fairly simple data in their web pages. The goal is to provide a minimal subset that is easy to learn and will work for 80% of authors doing simple data markup. </p> </section> <section property="bibo:hasPart" resource="#the-attributes" typeof="bibo:Chapter" id="the-attributes" class="informative"> <h2 resource="#h-the-attributes" id="h-the-attributes"><span property="xhv:role" resource="xhv:heading"><span class="secno">2. </span>The Attributes</span></h2><p><em>This section is non-normative.</em></p> <p> RDFa Lite consists of five simple attributes; <code>vocab</code>, <code>typeof</code>, <code>property</code>, <code>resource</code>, and <code>prefix</code>. RDFa 1.1 Lite is completely upwards compatible with the full set of RDFa 1.1 attributes. This means that if an author finds that RDFa Lite isn't powerful enough, transitioning to the full version of RDFa is just a matter of adding the more powerful RDFa attributes into the existing RDFa Lite markup. </p> <section property="bibo:hasPart" resource="#vocab-typeof-and-property" typeof="bibo:Chapter" id="vocab-typeof-and-property"> <h3 resource="#h-vocab-typeof-and-property" id="h-vocab-typeof-and-property"><span property="xhv:role" resource="xhv:heading"><span class="secno">2.1 </span>vocab, typeof, and property</span></h3> <p> RDFa, like Microformats [<cite><a href="#bib-microformats" class="bibref">microformats</a></cite>] and Microdata [<cite><a href="#bib-microdata" class="bibref">microdata</a></cite>], enables us to talk about <em>things</em> on the Web such that a machine can understand what we are saying. Typically when we talk about a thing, we use a particular <strong>vocabulary</strong> to talk about it. So, if you wanted to talk about People, the vocabulary that you would use would specify terms like <em>name</em> and <em>telephone number</em>. When we want to mark up things on the Web, we need to do something very similar, which is specify which vocabulary that we are going to be using. Here is a simple example that specifies a vocabulary that we intend to use to markup things in the paragraph: </p> <div class="example"><div class="example-title"><span>Example 1</span></div><pre class="example"><p <span style="color: #5b5; font-weight: bold;">vocab="http://schema.org/"</span>> My name is Manu Sporny and you can give me a ring via 1-800-555-0199. </p></pre></div> <p> In this example we have specified that we are going to be using the <strong>vocabulary</strong> that can be found at <code>http://schema.org/</code>. This is a vocabulary that has been released by major search engine companies to talk about common things on the Web that Search Engines care about – things like People, Places, Reviews, Recipes, and Events. Once we have specified the vocabulary, we need to specify the <strong>type of</strong> the thing that we're talking about. In this particular case we are talking about a Person, which can be marked up like so: </p> <div class="example"><div class="example-title"><span>Example 2</span></div><pre class="example"><p vocab="http://schema.org/" <span style="color: #5b5; font-weight: bold;">typeof="Person"</span>> My name is Manu Sporny and you can give me a ring via 1-800-555-0199. </p></pre></div> <p> Now all we need to do is specify which <strong>properties</strong> of that person we want to point out to the search engine. In the following example, we mark up the person's name, phone number and web page. Both text and URLs can be marked up with RDFa Lite. In the following example, pay particular attention to the types of data that are being pointed out to the search engine, which are highlighted in blue: </p> <div class="example"><div class="example-title"><span>Example 3</span></div><pre class="example"><p vocab="http://schema.org/" typeof="Person"> My name is <span <span style="color: #5b5; font-weight: bold;">property="name"</span>><span style="color: #55b; font-weight: bold;">Manu Sporny</span></span> and you can give me a ring via <span <span style="color: #5b5; font-weight: bold;">property="telephone"</span>><span style="color: #55b; font-weight: bold;">1-800-555-0199</span></span> or visit <a <span style="color: #5b5; font-weight: bold;">property="url"</span> href="<span style="color: #55b; font-weight: bold;">http://manu.sporny.org/</span>">my homepage</a>. </p></pre></div> <p> Now, when somebody types in “phone number for Manu Sporny” into a search engine, the search engine can more reliably answer the question directly, or point the person searching to a more relevant Web page. </p> </section> <section property="bibo:hasPart" resource="#resource" typeof="bibo:Chapter" id="resource"> <h3 resource="#h-resource" id="h-resource"><span property="xhv:role" resource="xhv:heading"><span class="secno">2.2 </span>resource</span></h3> <p> If you want Web authors to be able to talk <em>about</em> each thing on your page, you need to create an identifier for each of these things. Just like we create identifiers for parts of a page using the <code>id</code> attribute in HTML, you can create identifiers for things described on a page using the <code>resource</code> attribute: </p> <div class="example"><div class="example-title"><span>Example 4</span></div><pre class="example"><p vocab="http://schema.org/" <span style="color: #5b5; font-weight: bold;">resource="#manu"</span> typeof="Person"> My name is <span property="name">Manu Sporny</span> and you can give me a ring via <span property="telephone">1-800-555-0199</span>. <img property="image" src="http://manu.sporny.org/images/manu.png" /> </p></pre></div> <p> If we assume that the markup above can be found at <code>http://example.org/people</code>, then the identifier for the thing is the address, plus the value in the <code>resource</code> attribute. Therefore, the identifier for the thing on the page would be: <code>http://example.org/people#manu</code>. This identifier is also useful if you want to talk about that same thing on another Web page. By identifying all things on the Web using a unique Uniform Resource Locator (URL), we can start building a Web of things. Companies building software for the Web can use this Web of things to answer complex questions like: "What is Manu Sporny's phone number and what does he look like?". </p> </section> <section property="bibo:hasPart" resource="#prefix" typeof="bibo:Chapter" id="prefix"> <h3 resource="#h-prefix" id="h-prefix"><span property="xhv:role" resource="xhv:heading"><span class="secno">2.3 </span>prefix</span></h3> <p> In some cases, a vocabulary may not have all of the terms an author needs when describing their <em>thing</em>. The last feature in RDFa 1.1 Lite that some authors might need is the ability to specify more than one vocabulary. For example, if we are describing a Person and we need to specify that they have a favorite animal, we could do something like the following: </p> <div class="example"><div class="example-title"><span>Example 5</span></div><pre class="example"><p vocab="http://schema.org/" <span style="color: #5b5; font-weight: bold;">prefix="ov: http://open.vocab.org/terms/"</span> resource="#manu" typeof="Person"> My name is <span property="name">Manu Sporny</span> and you can give me a ring via <span property="telephone">1-800-555-0199</span>. <img property="image" src="http://manu.sporny.org/images/manu.png" /> My favorite animal is the <span <span style="color: #5b5; font-weight: bold;">property="ov:preferredAnimal"</span>><span style="color: #55b; font-weight: bold;">Liger</span></span>. </p></pre></div> <p> The example assigns a short-hand prefix to the Open Vocabulary (<code>ov</code>) and uses that prefix to specify the <code>preferredAnimal</code> vocabulary term. Since schema.org doesn't have a clear way of expressing a favorite animal, the author instead depends on this alternate vocabulary to get the job done. </p> <p> RDFa 1.1 Lite also pre-defines a number of <a href="https://www.w3.org/2011/rdfa-context/rdfa-1.1">useful and popular prefixes</a>, such as <code>dc</code>, <code>foaf</code>, and <code>schema</code>. This ensures that even if authors forget to declare the popular prefixes, that their structured data will continue to work. A full list of pre-declared prefixes can be found in the <a href="https://www.w3.org/2011/rdfa-context/rdfa-1.1">initial context document for RDFa 1.1</a>. </p> </section> <p> If you would like to learn more about what is possible with RDFa Lite, including an introduction to the data model, please read the section on RDFa Lite in the RDFa Primer [<cite><a href="#bib-rdfa-primer" class="bibref">rdfa-primer</a></cite>]. </p> </section> <section property="bibo:hasPart" resource="#conformance" typeof="bibo:Chapter" id="conformance"><h2 resource="#h-conformance" id="h-conformance"><span property="xhv:role" resource="xhv:heading"><span class="secno">3. </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 href="#bib-RFC2119" class="bibref">RFC2119</a></cite>]. </p> <section property="bibo:hasPart" resource="#document-conformance" typeof="bibo:Chapter" id="document-conformance"> <h3 resource="#h-document-conformance" id="h-document-conformance"><span property="xhv:role" resource="xhv:heading"><span class="secno">3.1 </span>Document Conformance</span></h3> <p> In order for a document to be labeled as a conforming <strong>RDFa Lite 1.1 document</strong>: </p> <ul> <li> It <em title="MUST" class="rfc2119">MUST</em> only require the facilities described as mandatory in its Host Language. </li> <li> It <em title="MUST NOT" class="rfc2119">MUST NOT</em> use any additional RDFa attributes other than <code>vocab</code>, <code>typeof</code>, <code>property</code>, <code>resource</code>, and <code>prefix</code>; it may also use <code>href</code> and <code>src</code>, when the Host Language authorizes the usage of those attributes. However, even if authorized by the Host Language, the usage of <code>rel</code> and <code>rev</code> <em title="SHOULD" class="rfc2119">SHOULD</em> be restricted to non-RDFa usage patterns, as defined by the Host Language. </li> <li> All RDFa attributes <em title="SHOULD" class="rfc2119">SHOULD</em> be used in a way that is conformant with [<cite><a href="#bib-rdfa-core" class="bibref">rdfa-core</a></cite>]. </li> <li> In XML-based languages, a document <em title="MAY" class="rfc2119">MAY</em> still be labeled as a conforming RDFa Lite 1.1 document as long as the usage of the <code>xmlns</code> attribute is not used to declare CURIE prefixes. </li> </ul> <p> If additional non-RDFa Lite attributes are used from the RDFa Core 1.1 specification, the document <em title="MUST" class="rfc2119">MUST</em> be referred to as a conforming <strong>RDFa 1.1 document</strong>. All conforming RDFa Lite 1.1 documents <em title="MAY" class="rfc2119">MAY</em> be referred to as conforming RDFa 1.1 documents. </p> </section> </section> <section property="bibo:hasPart" resource="#change-history-since-the-last-published-recommentation" typeof="bibo:Chapter" id="change-history-since-the-last-published-recommentation" class="informative"> <h2 resource="#changes" id="changes"><span property="xhv:role" resource="xhv:heading"><span class="secno">4. </span>Change History Since the Last Published Recommentation</span></h2><p><em>This section is non-normative.</em></p> <p>2014-12-16: Two grammatical errors have been changed in the Status Section</p> <p>2014-12-16: References to the other RDFa documents have been updated</p> <p>2014-12-16: The style of the references have been updated to the latest <code>respec</code> style</p> </section> <section property="bibo:hasPart" resource="#references" typeof="bibo:Chapter" id="references" class="appendix"><h2 resource="#h-references" id="h-references"><span property="xhv:role" resource="xhv:heading"><span class="secno">A. </span>References</span></h2><section property="bibo:hasPart" resource="#normative-references" typeof="bibo:Chapter" id="normative-references"><h3 resource="#h-normative-references" id="h-normative-references"><span property="xhv:role" resource="xhv:heading"><span class="secno">A.1 </span>Normative references</span></h3><dl resource="" class="bibliography"><dt id="bib-RFC2119">[RFC2119]</dt><dd>S. Bradner. <a property="dc:requires" href="https://tools.ietf.org/html/rfc2119"><cite>Key words for use in RFCs to Indicate Requirement Levels</cite></a>. March 1997. Best Current Practice. URL: <a property="dc:requires" href="https://tools.ietf.org/html/rfc2119">https://tools.ietf.org/html/rfc2119</a> </dd><dt id="bib-rdfa-core">[rdfa-core]</dt><dd>Ben Adida; Mark Birbeck; Shane McCarron; Ivan Herman et al. <a property="dc:requires" href="https://www.w3.org/TR/rdfa-core">RDFa Core 1.1 - Third Edition: Syntax and processing rules for embedding RDF through attributes</a>. 17 March 2015. W3C Recommendation. URL: <a property="dc:requires" href="https://www.w3.org/TR/rdfa-core/">http://www.w3.org/TR/rdfa-core/</a> </dd></dl></section><section property="bibo:hasPart" resource="#informative-references" typeof="bibo:Chapter" id="informative-references"><h3 resource="#h-informative-references" id="h-informative-references"><span property="xhv:role" resource="xhv:heading"><span class="secno">A.2 </span>Informative references</span></h3><dl resource="" class="bibliography"><dt id="bib-microdata">[microdata]</dt><dd>Ian Hickson. <a property="dc:references" href="https://www.w3.org/TR/microdata/"><cite>HTML Microdata</cite></a>. 29 October 2013. W3C Note. URL: <a property="dc:references" href="https://www.w3.org/TR/microdata/">http://www.w3.org/TR/microdata/</a> </dd><dt id="bib-microformats">[microformats]</dt><dd><a property="dc:references" href="http://microformats.org"><cite>Microformats</cite></a>. URL: <a property="dc:references" href="http://microformats.org">http://microformats.org</a> </dd><dt id="bib-rdfa-primer">[rdfa-primer]</dt><dd>Ben Adida; Ivan Herman; Manu Sporny; Mark Birbeck. <a property="dc:references" href="https://www.w3.org/TR/rdfa-primer/">RDFa 1.1 Primer - Third Edition</a>. 17 March 2015. W3C Note. URL: <a property="dc:references" href="https://www.w3.org/TR/rdfa-primer">http://www.w3.org/TR/rdfa-primer/</a> </dd></dl></section></section><script src="https://www.w3.org/scripts/TR/fixup.js"></script></body></html>