Update static REC of Concepts and add diff
authorMarkus Lanthaler <mail@markus-lanthaler.com>
Wed, 12 Feb 2014 16:19:17 +0100
changeset 1859 3bec7baa5ec1
parent 1858 02ba03843d73
child 1860 300282c6e916
child 1861 07f45f2a9fb5
Update static REC of Concepts and add diff
REC-drafts/REC-rdf11-concepts-20140225/Overview.html
REC-drafts/REC-rdf11-concepts-20140225/diff-20140109.html
--- a/REC-drafts/REC-rdf11-concepts-20140225/Overview.html	Wed Feb 12 15:52:52 2014 +0100
+++ b/REC-drafts/REC-rdf11-concepts-20140225/Overview.html	Wed Feb 12 16:19:17 2014 +0100
@@ -1,1668 +1,1520 @@
-<!DOCTYPE html>
-<html lang="en" typeof="bibo:Document w3p:REC" about="" property="dcterms:language" content="en" prefix="bibo: http://purl.org/ontology/bibo/ w3p: http://www.w3.org/2001/02pd/rec54#" xmlns="http://www.w3.org/1999/xhtml">
-<head>
-    <meta charset="utf-8" />
-    <title>RDF 1.1 Concepts and Abstract Syntax</title>
-    
-    
-    
-    <style type="text/css">
-      figure { text-align: center; }
-      table td, table th { border: 1px solid #ddd; padding: 0.2em 0.5em; }
-      ol ol { list-style-type: lower-latin; }
-    </style>
-  <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:  #ff4500;
-}
-
-/* --- 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;
-}
-
[email protected] print {
-    .removeOnSave {
-        display: none;
-    }
-}
-</style><style>/* --- ISSUES/NOTES --- */
-div.issue-title, div.note-title {
-    padding-right:  1em;
-    min-width: 7.5em;
-    color: #b9ab2d;
-}
-div.issue-title { color: #e05252; }
-div.note-title { color: #2b2; }
-div.issue-title span, div.note-title span {
-    text-transform: uppercase;
-}
-div.note, div.issue {
-    margin-top: 1em;
-    margin-bottom: 1em;
-}
-.note > p:first-child, .issue > p:first-child { margin-top: 0 }
-.issue, .note {
-    padding: .5em;
-    border-left-width: .5em;
-    border-left-style: solid;
-}
-div.issue, div.note {
-    padding: 1em 1.2em 0.5em;
-    margin: 1em 0;
-    position: relative;
-    clear: both;
-}
-span.note, span.issue { padding: .1em .5em .15em; }
-
-.issue {
-    border-color: #e05252;
-    background: #fbe9e9;
-}
-.note {
-    border-color: #52e052;
-    background: #e9fbe9;
-}
-
-
-</style><link rel="stylesheet" href="https://www.w3.org/StyleSheets/TR/W3C-REC" />
-<!--[if lt IE 9]><script src='https://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]-->
-</head>
-
-<body class="h-entry" role="document" id="respecDocument"><div class="head" role="contentinfo" id="respecHeader">
-  <p>
-    
-      <a href="http://www.w3.org/"><img width="72" height="48" alt="W3C" src="https://www.w3.org/Icons/w3c_home" /></a>
-    
-  </p>
-  <h1 property="dcterms:title" id="title" class="title p-name">RDF 1.1 Concepts and Abstract Syntax</h1>
-  
-  <h2 content="2014-02-24T23:00:00.000Z" datatype="xsd:dateTime" property="dcterms:issued" id="w3c-recommendation-25-february-2014"><abbr title="World Wide Web Consortium">W3C</abbr> Recommendation <time datetime="2014-02-25" class="dt-published">25 February 2014</time></h2>
-  <dl>
-    
-      <dt>This version:</dt>
-      <dd><a href="http://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/" class="u-url">http://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/</a></dd>
-      <dt>Latest published version:</dt>
-      <dd><a href="http://www.w3.org/TR/rdf11-concepts/">http://www.w3.org/TR/rdf11-concepts/</a></dd>
-    
-    
-    
-    
-      <dt>Implementation report:</dt>
-      <dd><a href="http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/">http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/</a></dd>
-    
-    
-    
-    
-      <dt>Previous version:</dt>
-      <dd><a href="http://www.w3.org/TR/2014/PR-rdf11-concepts-20140109/" rel="dcterms:replaces">http://www.w3.org/TR/2014/PR-rdf11-concepts-20140109/</a></dd>
-    
-    
-      
-          <dt>Previous Recommendation:</dt>
-          <dd><a href="http://www.w3.org/TR/rdf-concepts" rel="dcterms:replaces">http://www.w3.org/TR/rdf-concepts</a></dd>
-      
-    
-    <dt>Editors:</dt>
-    <dd inlist="" rel="bibo:editor" class="p-author h-card vcard"><span typeof="foaf:Person"><a href="http://richard.cyganiak.de/" content="Richard Cyganiak" property="foaf:name" rel="foaf:homepage" class="u-url url p-name fn">Richard Cyganiak</a>, <a href="http://www.deri.ie/" class="p-org org h-org h-card" rel="foaf:workplaceHomepage">DERI, NUI Galway</a></span>
-</dd>
-<dd inlist="" rel="bibo:editor" class="p-author h-card vcard"><span typeof="foaf:Person"><a href="http://about.me/david_wood" content="David Wood" property="foaf:name" rel="foaf:homepage" class="u-url url p-name fn">David Wood</a>, <a href="http://3roundstones.com/" class="p-org org h-org h-card" rel="foaf:workplaceHomepage">3 Round Stones</a></span>
-</dd>
-<dd inlist="" rel="bibo:editor" class="p-author h-card vcard"><span typeof="foaf:Person"><a href="http://www.markus-lanthaler.com/" content="Markus Lanthaler" property="foaf:name" rel="foaf:homepage" class="u-url url p-name fn">Markus Lanthaler</a>, <a href="http://www.tugraz.at/" class="p-org org h-org h-card" rel="foaf:workplaceHomepage">Graz University of Technology</a></span>
-</dd>
-
-    
-    
-      
-        
-          <dt>Previous Editors:</dt>
-          
-             
-                
-                  <dd>
-                    
-                      Graham Klyne
-                    
-                  </dd>
-                
-             
-                
-                  <dd>
-                    
-                      Jeremy J. Carroll
-                    
-                  </dd>
-                
-             
-                
-                  <dd>
-                    
-                      Brian McBride
-                    
-                  </dd>
-                
-             
-          
-        
-      
-    
-  </dl>
-  
-    <p>
-      Please check the <a href="http://www.w3.org/2014/rdf1.1-errata"><strong>errata</strong></a> for any errors or issues
-      reported since publication.
-    </p>
-  
-  
-  
-    <p>
-      The English version of this specification is the only normative version. Non-normative
-      <a href="http://www.w3.org/Consortium/Translation/">translations</a> may also be available.
-    </p>
-  
-  
-    
-      <p class="copyright">
-        <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> ©
-        2004-2014
-        
-        <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>), 
-        
-        All Rights Reserved.
-        
-        <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 href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a>
-        
-        rules apply.
-      </p>
-    
-  
-  <hr />
-</div>
-
-
-  <section id="abstract" class="introductory" property="dcterms:abstract" datatype="" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h2 aria-level="1" role="heading" id="h2_abstract">Abstract</h2>
-
-      <p>The Resource Description Framework (RDF) is a framework for
-      representing information in the Web. This document defines an abstract syntax
-      (a data model) which serves to link all RDF-based languages and
-      specifications. The abstract syntax has two key data structures:
-      RDF graphs are sets of subject-predicate-object triples,
-      where the elements may be IRIs, blank nodes, or datatyped literals. They
-      are used to express descriptions of resources. RDF datasets are used
-      to organize collections of RDF graphs, and comprise a default graph
-      and zero or more named graphs. RDF 1.1 Concepts and Abstract Syntax
-      also introduces key concepts and terminology, and discusses
-      datatyping and the handling of fragment identifiers in IRIs within
-      RDF graphs.</p>
-  </section><section class="introductory" id="sotd" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h2 aria-level="1" role="heading" id="h2_sotd">Status of This Document</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>This document is part of the RDF 1.1 document suite. It is the
-    central RDF 1.1 document and defines the core RDF concepts. A new
-    concept in RDF 1.1 is the notion of an RDF dataset to represent
-    multiple graphs. </p>
-  
-        <p>
-          This document was published by the <a href="http://www.w3.org/2011/rdf-wg/">RDF Working Group</a> as a Recommendation.
-          
-          
-            If you wish to make comments regarding this document, please send them to 
-            <a href="mailto:[email protected]">[email protected]</a> 
-            (<a href="mailto:[email protected]?subject=subscribe">subscribe</a>,
-            <a href="http://lists.w3.org/Archives/Public/public-rdf-comments/">archives</a>).
-          
-          
-          
-          
-            All comments are welcome.
-          
-        </p>
-        
-          <p>
-            Please see the Working Group's  <a href="http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/">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 href="http://www.w3.org/Consortium/Patent-Policy-20040205/" rel="w3p:patentRules" about="" id="sotd_patent">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 rel="disclosure" href="http://www.w3.org/2004/01/pp-impl/46168/status">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>
-        
-      
-    
-  
-</section><section id="toc"><h2 class="introductory" aria-level="1" role="heading" id="h2_toc">Table of Contents</h2><ul class="toc" role="directory" id="respecContents"><li class="tocline"><a href="#section-Introduction" class="tocxref"><span class="secno">1. </span>Introduction</a><ul class="toc"><li class="tocline"><a href="#data-model" class="tocxref"><span class="secno">1.1 </span>Graph-based Data Model</a></li><li class="tocline"><a href="#resources-and-statements" class="tocxref"><span class="secno">1.2 </span>Resources and Statements</a></li><li class="tocline"><a href="#referents" class="tocxref"><span class="secno">1.3 </span>The Referent of an <abbr title="Internationalized Resource Identifier">IRI</abbr></a></li><li class="tocline"><a href="#vocabularies" class="tocxref"><span class="secno">1.4 </span>RDF Vocabularies and Namespace IRIs</a></li><li class="tocline"><a href="#change-over-time" class="tocxref"><span class="secno">1.5 </span>RDF and Change over Time</a></li><li class="tocline"><a href="#managing-graphs" class="tocxref"><span class="secno">1.6 </span>Working with Multiple RDF Graphs</a></li><li class="tocline"><a href="#entailment" class="tocxref"><span class="secno">1.7 </span>Equivalence, Entailment and Inconsistency</a></li><li class="tocline"><a href="#rdf-documents" class="tocxref"><span class="secno">1.8 </span>RDF Documents and Syntaxes</a></li></ul></li><li class="tocline"><a href="#conformance" class="tocxref"><span class="secno">2. </span>Conformance</a></li><li class="tocline"><a href="#section-rdf-graph" class="tocxref"><span class="secno">3. </span>RDF Graphs</a><ul class="toc"><li class="tocline"><a href="#section-triples" class="tocxref"><span class="secno">3.1 </span>Triples</a></li><li class="tocline"><a href="#section-IRIs" class="tocxref"><span class="secno">3.2 </span>IRIs</a></li><li class="tocline"><a href="#section-Graph-Literal" class="tocxref"><span class="secno">3.3 </span>Literals</a></li><li class="tocline"><a href="#section-blank-nodes" class="tocxref"><span class="secno">3.4 </span>Blank Nodes</a></li><li class="tocline"><a href="#section-skolemization" class="tocxref"><span class="secno">3.5 </span>Replacing Blank Nodes with IRIs</a></li><li class="tocline"><a href="#graph-isomorphism" class="tocxref"><span class="secno">3.6 </span>Graph Comparison</a></li></ul></li><li class="tocline"><a href="#section-dataset" class="tocxref"><span class="secno">4. </span>RDF Datasets</a><ul class="toc"><li class="tocline"><a href="#section-dataset-isomorphism" class="tocxref"><span class="secno">4.1 </span>RDF Dataset Comparison</a></li><li class="tocline"><a href="#section-dataset-conneg" class="tocxref"><span class="secno">4.2 </span>Content Negotiation of RDF Datasets</a></li></ul></li><li class="tocline"><a href="#section-Datatypes" class="tocxref"><span class="secno">5. </span>Datatypes</a><ul class="toc"><li class="tocline"><a href="#xsd-datatypes" class="tocxref"><span class="secno">5.1 </span>The XML Schema Built-in Datatypes</a></li><li class="tocline"><a href="#section-html" class="tocxref"><span class="secno">5.2 </span>The <code>rdf:HTML</code> Datatype</a></li><li class="tocline"><a href="#section-XMLLiteral" class="tocxref"><span class="secno">5.3 </span>The <code>rdf:XMLLiteral</code> Datatype</a></li><li class="tocline"><a href="#datatype-iris" class="tocxref"><span class="secno">5.4 </span>Datatype IRIs</a></li></ul></li><li class="tocline"><a href="#section-fragID" class="tocxref"><span class="secno">6. </span>Fragment Identifiers</a></li><li class="tocline"><a href="#section-generalized-rdf" class="tocxref"><span class="secno">7. </span>Generalized RDF Triples, Graphs, and Datasets</a></li><li class="tocline"><a href="#section-Acknowledgments" class="tocxref"><span class="secno">8. </span>Acknowledgments</a></li><li class="tocline"><a href="#changes" class="tocxref"><span class="secno">A. </span>Changes between RDF 1.0 and RDF 1.1</a></li><li class="tocline"><a href="#change-log" class="tocxref"><span class="secno">B. </span>Changes since Proposed Recommendation</a></li><li class="tocline"><a href="#references" class="tocxref"><span class="secno">C. </span>References</a><ul class="toc"><li class="tocline"><a href="#normative-references" class="tocxref"><span class="secno">C.1 </span>Normative references</a></li><li class="tocline"><a href="#informative-references" class="tocxref"><span class="secno">C.2 </span>Informative references</a></li></ul></li></ul></section>
-
-  
-
-<section class="informative" id="section-Introduction" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_section-Introduction"><span class="secno">1. </span>Introduction</h2><p><em>This section is non-normative.</em></p>
-
-    <p>The <em>Resource Description Framework</em> (RDF) is a framework
-    for representing information in the Web.</p>
-
-    <p>This document defines an abstract syntax (a data model)
-    which serves to link all RDF-based languages and specifications,
-    including:</p>
-
-    <ul>
-      <li>the <a href="http://www.w3.org/TR/rdf11-mt/">formal
-      model-theoretic semantics for RDF and RDFS</a> [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>].</li>
-
-      <li>serialization syntaxes for storing and exchanging RDF
-      (e.g., <a href="http://www.w3.org/TR/turtle/">Turtle</a> [<cite><a class="bibref" href="#bib-TURTLE">TURTLE</a></cite>]
-      and <a href="http://www.w3.org/TR/json-ld/">JSON-LD</a> [<cite><a class="bibref" href="#bib-JSON-LD">JSON-LD</a></cite>]),</li>
-
-      <li>the <a href="http://www.w3.org/TR/rdf-sparql-query/">SPARQL
-      Query Language</a> [<cite><a class="bibref" href="#bib-SPARQL11-OVERVIEW">SPARQL11-OVERVIEW</a></cite>],</li>
-
-      <li>the <a href="http://www.w3.org/TR/rdf-schema/">RDF Vocabulary
-      Description Language</a> (RDFS) [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>],</li>
-    </ul>
-
-<section id="data-model" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_data-model"><span class="secno">1.1 </span>Graph-based Data Model</h3>
-
-    <p>The core structure of the abstract syntax is a set of
-    <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">triples</a>, each consisting of a <a href="#dfn-subject" class="internalDFN">subject</a>,
-    a <a href="#dfn-predicate" class="internalDFN">predicate</a> and an <a href="#dfn-object" class="internalDFN">object</a>. A set of such triples is called
-    an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>. An RDF graph can be visualized as a node and
-    directed-arc diagram, in which each triple is represented as a
-    node-arc-node link.</p>
-
-    <figure id="fig-an-rdf-graph-with-two-nodes-subject-and-object-and-a-triple-connecting-them-predicate">
-      <a href="rdf-graph.svg"><img alt="An RDF graph with two nodes (Subject and Object) and a triple connecting them (Predicate)" src="rdf-graph.svg" /></a>
-      <figcaption>Fig. <span class="figno">1</span> <span class="fig-title">An RDF graph with two nodes (Subject and Object) and a triple connecting them (Predicate)</span></figcaption>
-    </figure>
-
-    <p>There can be three kinds of <a title="node" href="#dfn-node" class="internalDFN">nodes</a> in an
-    <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>: <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>, <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>,
-    and <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a>.</p>
-</section>
-
-
-<section id="resources-and-statements" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_resources-and-statements"><span class="secno">1.2 </span>Resources and Statements</h3>
-
-    <p>Any <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or <a href="#dfn-literal" class="internalDFN">literal</a> <dfn title="denote" id="dfn-denote">denotes</dfn>
-    something in the world (the &quot;universe of discourse&quot;).
-    These things are called
-    <dfn title="resource" id="dfn-resource">resources</dfn>. Anything can be a resource,
-    including physical things, documents, abstract concepts, numbers
-    and strings; the term is synonymous with &quot;entity&quot; as it is used in
-    the RDF Semantics specification [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>].
-    The resource denoted by an <abbr title="Internationalized Resource Identifier">IRI</abbr> is called its <a href="#dfn-referent" class="internalDFN">referent</a>, and the
-    resource denoted by a literal is called its
-    <a title="literal value" href="#dfn-literal-value" class="internalDFN">literal value</a>. Literals have
-    <a title="datatype" href="#dfn-datatype" class="internalDFN">datatypes</a> that define the range of possible
-    values, such as strings, numbers, and dates. Special kind of literals,
-    <a title="language-tagged string" href="#dfn-language-tagged-string" class="internalDFN">language-tagged strings</a>, denote
-    plain-text strings in a natural language.</p>
-
-    <p>Asserting an <a href="#dfn-rdf-triple" class="internalDFN">RDF triple</a> says that <em>some relationship,
-    indicated by the <a href="#dfn-predicate" class="internalDFN">predicate</a>, holds between the
-    <a title="resource" href="#dfn-resource" class="internalDFN">resources</a> <a title="denote" href="#dfn-denote" class="internalDFN">denoted</a> by
-    the <a href="#dfn-subject" class="internalDFN">subject</a> and <a href="#dfn-object" class="internalDFN">object</a></em>. This statement corresponding
-    to an RDF triple is known as an <dfn id="dfn-rdf-statement">RDF statement</dfn>.
-    The predicate itself is an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> and denotes a <dfn id="dfn-property">property</dfn>,
-    that is, a <a href="#dfn-resource" class="internalDFN">resource</a> that can be thought of as a binary relation.
-    (Relations that involve more than two entities can only be
-    <a href="http://www.w3.org/TR/swbp-n-aryRelations/">indirectly
-    expressed in RDF</a> [<cite><a class="bibref" href="#bib-SWBP-N-ARYRELATIONS">SWBP-N-ARYRELATIONS</a></cite>].)</p>
-
-    <p>Unlike <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> and <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>,
-      <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a> do not identify specific
-      <a title="resource" href="#dfn-resource" class="internalDFN">resources</a>. <a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">Statements</a>
-      involving blank nodes say that something with the given relationships
-      exists, without explicitly naming it.</p>
-</section>
-
-
-<section id="referents" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_referents"><span class="secno">1.3 </span>The Referent of an <abbr title="Internationalized Resource Identifier">IRI</abbr></h3>
-
-    <p>The <a href="#dfn-resource" class="internalDFN">resource</a> <a title="denote" href="#dfn-denote" class="internalDFN">denoted</a> by an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>
-      is also called its <dfn id="dfn-referent">referent</dfn>. For some IRIs with particular
-      meanings, such as those identifying XSD datatypes, the referent is
-      fixed by this specification. For all other IRIs, what exactly is
-      denoted by any given <abbr title="Internationalized Resource Identifier">IRI</abbr> is not defined by this specification. Other
-      specifications may fix <abbr title="Internationalized Resource Identifier">IRI</abbr> referents, or apply other constraints on
-      what may be the referent of any <abbr title="Internationalized Resource Identifier">IRI</abbr>.</p>
-
-    <p>Guidelines for determining the <a href="#dfn-referent" class="internalDFN">referent</a> of an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> are
-    provided in other documents, like
-    <em><a href="http://www.w3.org/TR/webarch/">Architecture of the World Wide Web, Volume One</a></em> [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>]
-    and <em><a href="http://www.w3.org/TR/cooluris/">Cool URIs for the Semantic Web</a></em> [<cite><a class="bibref" href="#bib-COOLURIS">COOLURIS</a></cite>].
-    A very brief, informal, and partial account follows:</p>
-
-    <ul>
-      <li>By design, IRIs have global scope. Thus, two different appearances of an <abbr title="Internationalized Resource Identifier">IRI</abbr>
-        <a href="#dfn-denote" class="internalDFN">denote</a> the same <a href="#dfn-resource" class="internalDFN">resource</a>. Violating this principle constitutes
-        an <a href="http://www.w3.org/TR/webarch/#URI-collision"><abbr title="Internationalized Resource Identifier">IRI</abbr> collision</a> [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>].</li>
-
-      <li>By social convention, the
-        <a href="http://www.w3.org/TR/webarch/#uri-ownership"><abbr title="Internationalized Resource Identifier">IRI</abbr> owner</a>
-        [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>] gets to say what the intended (or usual)
-        referent of an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> is.  Applications and users need not
-        abide by this intended denotation, but there may be a loss of
-        interoperability with other applications and users if they do
-        not do so.</li>
-
-      <li>The <abbr title="Internationalized Resource Identifier">IRI</abbr> owner can establish the intended <a href="#dfn-referent" class="internalDFN">referent</a>
-        by means of a specification or other document that explains
-        what is denoted. For example, the
-        <a href="http://www.w3.org/TR/vocab-org/">Organization Ontology document</a> [<cite><a class="bibref" href="#bib-VOCAB-ORG">VOCAB-ORG</a></cite>]
-        specifies the intended referents of various IRIs that start with
-        <code>http://www.w3.org/ns/org#</code>.</li>
-
-      <li>A good way of communicating the intended referent
-        is to set up the <abbr title="Internationalized Resource Identifier">IRI</abbr> so that it
-        <a href="http://www.w3.org/TR/webarch/#uri-dereference">dereferences</a> [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>]
-        to such a document.</li>
-
-      <li>Such a document can, in fact, be an <a href="#dfn-rdf-document" class="internalDFN">RDF document</a>
-        that describes the denoted resource by means of
-        <a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">RDF statements</a>.</li>
-    </ul>
-
-    <p>Perhaps the most important characteristic of <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>
-      in web architecture is that they can be
-      <a href="http://www.w3.org/TR/webarch/#uri-dereference">dereferenced</a>,
-      and hence serve as starting points for interactions with a remote server.
-      This specification is not concerned with such interactions.
-      It does not define an interaction model. It only treats IRIs as globally
-      unique identifiers in a graph data model that describes resources.
-      However, those interactions are critical to the concept of
-      <em><a href="http://www.w3.org/DesignIssues/LinkedData.html">Linked Data</a></em> [<cite><a class="bibref" href="#bib-LINKED-DATA">LINKED-DATA</a></cite>],
-      which makes use of the RDF data model and serialization formats.</p>
-</section>
-
-<section id="vocabularies" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_vocabularies"><span class="secno">1.4 </span>RDF Vocabularies and Namespace IRIs</h3>
-
-    <p>An <dfn id="dfn-rdf-vocabulary">RDF vocabulary</dfn> is a collection of <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>
-      intended for use in <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>. For example,
-      the IRIs documented in [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>] are the RDF Schema vocabulary.
-      RDF Schema can itself be used to define and document additional
-      RDF vocabularies. Some such vocabularies are mentioned in the
-      Primer [<cite><a class="bibref" href="#bib-RDF11-PRIMER">RDF11-PRIMER</a></cite>].</p>
-
-    <p>The <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> in an <a href="#dfn-rdf-vocabulary" class="internalDFN">RDF vocabulary</a> often begin with
-      a common substring known as a <dfn id="dfn-namespace-iri">namespace <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>.
-      Some namespace IRIs are associated by convention with a short name
-      known as a <dfn id="dfn-namespace-prefix">namespace prefix</dfn>. Some examples:
-
-    </p><table class="simple">
-      <caption>Some example namespace prefixes and IRIs</caption>
-      <tbody><tr>
-        <th>Namespace prefix</th>
-        <th>Namespace <abbr title="Internationalized Resource Identifier">IRI</abbr></th>
-        <th>RDF vocabulary</th>
-      </tr>
-      <tr>
-        <td>rdf</td>
-        <td><a href="http://www.w3.org/1999/02/22-rdf-syntax-ns#"><code>http://www.w3.org/1999/02/22-rdf-syntax-ns#</code></a></td>
-        <td>The RDF built-in vocabulary [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>]</td>
-      </tr>
-      <tr><td>rdfs</td>
-        <td><a href="http://www.w3.org/2000/01/rdf-schema#"><code>http://www.w3.org/2000/01/rdf-schema#</code></a></td>
-        <td>The RDF Schema vocabulary [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>]</td>
-      </tr>
-      <tr><td>xsd</td>
-        <td><a href="http://www.w3.org/2001/XMLSchema#"><code>http://www.w3.org/2001/XMLSchema#</code></a></td>
-        <td>The <a href="#dfn-rdf-compatible-xsd-types" class="internalDFN">RDF-compatible XSD types</a></td>
-      </tr>
-    </tbody></table>
-
-    <p>In some serialization formats it is common to abbreviate <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>
-      that start with <a title="namespace IRI" href="#dfn-namespace-iri" class="internalDFN">namespace IRIs</a> by using a
-      <a href="#dfn-namespace-prefix" class="internalDFN">namespace prefix</a> in order to assist readability. For example, the <abbr title="Internationalized Resource Identifier">IRI</abbr>
-      <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>
-      would be abbreviated as <code>rdf:XMLLiteral</code>.
-      Note however that these abbreviations are <em>not</em> valid IRIs,
-      and must not be used in contexts where IRIs are expected.
-      Namespace IRIs and namespace prefixes are <em>not</em> a formal part of the
-      RDF data model. They are merely a syntactic convenience for
-      abbreviating IRIs.</p>
-
-    <p>The term “<dfn id="dfn-namespace">namespace</dfn>” on its own does not have a
-      well-defined meaning in the context of RDF, but is sometimes informally
-      used to mean “<a href="#dfn-namespace-iri" class="internalDFN">namespace <abbr title="Internationalized Resource Identifier">IRI</abbr></a>” or “<a href="#dfn-rdf-vocabulary" class="internalDFN">RDF vocabulary</a>”.</p>
-</section>
-
-
-<section id="change-over-time" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_change-over-time"><span class="secno">1.5 </span>RDF and Change over Time</h3>
-
-    <p>The RDF data model is <em>atemporal</em>: <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>
-      are static snapshots of information.</p>
-
-    <p>However, <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a> can express information
-      about events and about temporal aspects of other entities,
-      given appropriate <a title="RDF vocabulary" href="#dfn-rdf-vocabulary" class="internalDFN">vocabulary</a> terms.</p>
-
-    <p>Since <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a> are defined as mathematical
-      sets, adding or removing <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">triples</a> from an
-      RDF graph yields a different RDF graph.</p>
-
-    <p>We informally use the term <dfn id="dfn-rdf-source">RDF source</dfn> to refer to a
-      persistent yet mutable source or container of
-      <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>. An RDF source is a <a href="#dfn-resource" class="internalDFN">resource</a>
-      that may be said to have a state that can change over time.
-      A snapshot of the state can be expressed as an RDF graph.
-      For example, any web document that has an RDF-bearing representation
-      may be considered an RDF source. Like all resources, RDF sources may
-      be named with <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> and therefore described in
-      other RDF graphs.</p>
-
-    <p>Intuitively speaking, changes in the universe of discourse
-      can be reflected in the following ways:</p>
-
-    <ul>
-      <li>An <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>, once minted, should never
-        change its intended <a href="#dfn-referent" class="internalDFN">referent</a>. (See
-        <a href="http://www.w3.org/TR/webarch/#URI-persistence"><abbr title="Uniform Resource Identifier">URI</abbr> persistence</a>
-        [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>].)</li>
-      <li><a title="literal" href="#dfn-literal" class="internalDFN">Literals</a>, by design, are constants and
-        never change their <a title="literal value" href="#dfn-literal-value" class="internalDFN">value</a>.</li>
-      <li>A relationship that holds between two <a title="resource" href="#dfn-resource" class="internalDFN">resources</a>
-        at one time may not hold at another time.</li>
-      <li><a title="RDF source" href="#dfn-rdf-source" class="internalDFN">RDF sources</a> may change their state over time.
-        That is, they may provide different <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>
-        at different times.</li>
-      <li>Some <a title="RDF source" href="#dfn-rdf-source" class="internalDFN">RDF sources</a> may, however, be immutable
-        snapshots of another RDF source, archiving its state at some
-        point in time.</li>
-    </ul>
-
-</section>
-
-
-<section id="managing-graphs" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_managing-graphs"><span class="secno">1.6 </span>Working with Multiple RDF Graphs</h3>
-
-    <p>As RDF graphs are sets of triples, they can be
-    combined easily, supporting the use of data from
-    multiple sources. Nevertheless, it is sometimes desirable to work
-    with multiple RDF graphs while keeping their contents separate.
-    <a title="RDF dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF datasets</a> support this requirement.</p>
-
-    <p>An <a href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a> is a collection of
-    <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>. All but one of these graphs have
-    an associated <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or blank node. They are called
-    <a title="named graph" href="#dfn-named-graph" class="internalDFN">named graphs</a>, and the <abbr title="Internationalized Resource Identifier">IRI</abbr> or blank node
-    is called the <a href="#dfn-graph-name" class="internalDFN">graph name</a>.
-    The remaining graph does not have an associated <abbr title="Internationalized Resource Identifier">IRI</abbr>, and is called
-    the <a href="#dfn-default-graph" class="internalDFN">default graph</a> of the RDF dataset.</p>
-
-    <p>There are many possible uses for <a title="RDF dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF datasets</a>.
-    One such use is to hold snapshots of multiple
-    <a title="RDF source" href="#dfn-rdf-source" class="internalDFN">RDF sources</a>.</p>
-</section>
-
-
-<section id="entailment" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_entailment"><span class="secno">1.7 </span>Equivalence, Entailment and Inconsistency</h3>
-
-    <p>An <a href="#dfn-rdf-triple" class="internalDFN">RDF triple</a> encodes a <a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">statement</a>—a
-    simple <dfn id="dfn-logical-expression">logical expression</dfn>, or claim about the world.
-    An <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> is the conjunction (logical <em>AND</em>) of
-    its triples.   The precise details of this meaning of RDF triples and graphs are
-    the subject of the RDF Semantics specification [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>], which yields the
-    following relationships between <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>s:</p>
-
-    <dl>
-    <dt><dfn id="dfn-entailment">Entailment</dfn></dt>
-    <dd>An <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> <em>A</em> entails another RDF graph <em>B</em>
-    if every possible arrangement of the world
-    that makes <em>A</em> true also makes <em>B</em> true. When <em>A</em>
-    entails <em>B</em>, if the truth of <em>A</em> is presumed or demonstrated
-    then the truth of <em>B</em> is established.</dd>
-
-    <dt><dfn id="dfn-equivalence">Equivalence</dfn></dt>
-    <dd>Two <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a> <em>A</em> and <em>B</em>
-    are equivalent if they make the same claim about the world.
-    <em>A</em> is equivalent to <em>B</em> if and only if
-    <em>A</em> <a title="entailment" href="#dfn-entailment" class="internalDFN">entails</a> <em>B</em> and
-    <em>B</em> entails <em>A</em>.</dd>
-
-    <dt><dfn id="dfn-inconsistency">Inconsistency</dfn></dt>
-    <dd>An <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> is inconsistent if it contains
-    an internal contradiction. There is no possible arrangement
-    of the world that would make the expression true.</dd>
-    </dl>
-
-    <p>An <dfn id="dfn-entailment-regime">entailment regime</dfn> [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>] is a specification that
-    defines precise conditions that make these relationships hold.
-    RDF itself recognizes only some basic cases of entailment, equivalence
-    and inconsistency. Other specifications, such as
-    <a href="http://www.w3.org/TR/rdf-schema/">RDF Schema</a> [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>]
-    and <a href="http://www.w3.org/TR/owl2-overview/">OWL 2</a>
-    [<cite><a class="bibref" href="#bib-OWL2-OVERVIEW">OWL2-OVERVIEW</a></cite>], add more powerful entailment regimes,
-    as do some domain-specific <a title="RDF vocabulary" href="#dfn-rdf-vocabulary" class="internalDFN">vocabularies</a>.
-    </p>
-
-    <p>This specification does not constrain how implementations
-    use the logical relationships defined by
-    <a title="entailment regime" href="#dfn-entailment-regime" class="internalDFN">entailment regimes</a>.
-    Implementations may or may not detect
-    <a title="inconsistency" href="#dfn-inconsistency" class="internalDFN">inconsistencies</a>, and may make all,
-    some or no <a title="entailment" href="#dfn-entailment" class="internalDFN">entailed</a> information
-    available to users.</p>
-</section>
-
-
-<section id="rdf-documents" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_rdf-documents"><span class="secno">1.8 </span>RDF Documents and Syntaxes</h3>
-
-    <p>An <dfn id="dfn-rdf-document">RDF document</dfn> is a document that encodes an
-    <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> or <a href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a> in a <dfn id="dfn-concrete-rdf-syntax">concrete RDF syntax</dfn>,
-    such as Turtle [<cite><a class="bibref" href="#bib-TURTLE">TURTLE</a></cite>], RDFa [<cite><a class="bibref" href="#bib-RDFA-PRIMER">RDFA-PRIMER</a></cite>], JSON-LD [<cite><a class="bibref" href="#bib-JSON-LD">JSON-LD</a></cite>], or
-    TriG [<cite><a class="bibref" href="#bib-TRIG">TRIG</a></cite>]. RDF documents enable the exchange of RDF graphs and RDF
-    datasets between systems.</p>
-
-    <p>A <a href="#dfn-concrete-rdf-syntax" class="internalDFN">concrete RDF syntax</a> may offer
-    many different ways to encode the same <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> or
-    <a href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a>, for example through the use of
-    <a title="namespace prefix" href="#dfn-namespace-prefix" class="internalDFN">namespace prefixes</a>,
-    relative IRIs, <a title="blank node identifier" href="#dfn-blank-node-identifier" class="internalDFN">blank node identifiers</a>,
-    and different ordering of statements. While these aspects can have great
-    effect on the convenience of working with the <a href="#dfn-rdf-document" class="internalDFN">RDF document</a>,
-    they are not significant for its meaning.</p>
-</section>
-
-
-</section>
-
-
-<section id="conformance" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_conformance"><span class="secno">2. </span>Conformance</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>
-  The key words <em class="rfc2119" title="MUST">MUST</em>, <em class="rfc2119" title="MUST NOT">MUST NOT</em>, <em class="rfc2119" title="REQUIRED">REQUIRED</em>, <em class="rfc2119" title="SHOULD">SHOULD</em>, <em class="rfc2119" title="SHOULD NOT">SHOULD NOT</em>, <em class="rfc2119" title="RECOMMENDED">RECOMMENDED</em>, <em class="rfc2119" title="MAY">MAY</em>,
-  and <em class="rfc2119" title="OPTIONAL">OPTIONAL</em> in this specification are to be interpreted as described in [<cite><a class="bibref" href="#bib-RFC2119">RFC2119</a></cite>].
-</p>
-
-    <p>This specification, <em>RDF 1.1 Concepts and Abstract Syntax</em>,
-    defines a data model and related terminology for use in
-    other specifications, such as
-    <a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">concrete RDF syntaxes</a>,
-    API specifications, and query languages.
-    Implementations cannot directly conform to
-    <em>RDF 1.1 Concepts and Abstract Syntax</em>,
-    but can conform to such other specifications that normatively
-    reference terms defined here.</p>
-</section>
-
-
-<section id="section-rdf-graph" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_section-rdf-graph"><span class="secno">3. </span>RDF Graphs</h2>
-
-    <p>An <dfn id="dfn-rdf-graph">RDF graph</dfn> is a set of
-    <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">RDF triples</a>.</p>
-
-
-<section id="section-triples" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-triples"><span class="secno">3.1 </span>Triples</h3>
-
-    <p>An <dfn id="dfn-rdf-triple">RDF triple</dfn> consists of three components:</p>
-
-    <ul>
-      <li>the <dfn id="dfn-subject">subject</dfn>, which is an
-      <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a <a href="#dfn-blank-node" class="internalDFN">blank node</a></li>
-
-      <li>the <dfn id="dfn-predicate">predicate</dfn>, which is an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a></li>
-
-      <li>the <dfn id="dfn-object">object</dfn>, which is an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>,
-      a <a href="#dfn-literal" class="internalDFN">literal</a> or a <a href="#dfn-blank-node" class="internalDFN">blank node</a></li>
-    </ul>
-
-    <p>An RDF triple is conventionally written in the order subject,
-    predicate, object.</p>
-
-    <p>The set of <dfn title="node" id="dfn-node">nodes</dfn> of an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>
-    is the set of subjects and objects of triples in the graph.
-    It is possible for a predicate <abbr title="Internationalized Resource Identifier">IRI</abbr> to also occur as a node in
-    the same graph.</p>
-
-    <p><a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>, <a title="literal" href="#dfn-literal" class="internalDFN">literals</a> and
-    <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a> are collectively known as
-    <dfn title="RDF term" id="dfn-rdf-term">RDF terms</dfn>.</p>
-
-    <p><a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>, <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>
-    and <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a> are distinct and distinguishable.
-    For example, <code>http://example.org/</code> as a string literal
-    is neither equal to <code>http://example.org/</code> as an <abbr title="Internationalized Resource Identifier">IRI</abbr>,
-    nor to a blank node with the <a href="#dfn-blank-node-identifier" class="internalDFN">blank node identifier</a>
-    <code>http://example.org/</code>.</p>
-</section>
-
-
-<section id="section-IRIs" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-IRIs"><span class="secno">3.2 </span>IRIs</h3>
-
-    <p>An <dfn title="IRI" id="dfn-iri"><abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>
-    (Internationalized Resource Identifier) within an RDF graph
-    is a Unicode string [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] that conforms to the syntax
-    defined in RFC 3987 [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>].</p>
-
-    <p>IRIs in the RDF abstract syntax <em class="rfc2119" title="MUST">MUST</em> be absolute, and <em class="rfc2119" title="MAY">MAY</em>
-    contain a fragment identifier.</p>
-
-    <p><dfn id="dfn-iri-equality"><abbr title="Internationalized Resource Identifier">IRI</abbr> equality</dfn>:
-    Two IRIs are equal if and only if they are equivalent
-    under Simple String Comparison according to
-    <a href="http://tools.ietf.org/html/rfc3987#section-5.1">section 5.1</a>
-    of [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>]. Further normalization <em class="rfc2119" title="MUST NOT">MUST NOT</em> be performed when
-    comparing IRIs for equality.</p>
-
-    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_1"><span>Note</span></div><div id="note-iris" class="">
-    <p><strong>URIs and IRIs:</strong>
-    IRIs are a generalization of
-    <dfn title="URI" id="dfn-uri"><abbr title="Uniform Resource Identifier">URI</abbr>s</dfn>
-    [<cite><a class="bibref" href="#bib-RFC3986">RFC3986</a></cite>] that permits a wider range of Unicode characters.
-    Every absolute <abbr title="Uniform Resource Identifier">URI</abbr> and URL is an <abbr title="Internationalized Resource Identifier">IRI</abbr>, but not every <abbr title="Internationalized Resource Identifier">IRI</abbr> is an <abbr title="Uniform Resource Identifier">URI</abbr>.
-    When IRIs are used in operations that are only
-    defined for URIs, they must first be converted according to
-    the mapping defined in
-    <a href="http://tools.ietf.org/html/rfc3987#section-3.1">section 3.1</a>
-    of [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>]. A notable example is retrieval over the HTTP
-    protocol. The mapping involves UTF-8 encoding of non-ASCII
-    characters, %-encoding of octets not allowed in URIs, and
-    Punycode-encoding of domain names.</p>
-
-    <p><strong>Relative IRIs:</strong>
-    Some <a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">concrete RDF syntaxes</a> permit
-    <dfn title="relative IRI" id="dfn-relative-iri">relative IRIs</dfn> as a convenient shorthand
-    that allows authoring of documents independently from their final
-    publishing location. Relative IRIs must be
-    <a href="http://tools.ietf.org/html/rfc3986#section-5.2">resolved
-    against</a> a <dfn id="dfn-base-iri">base <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn> to make them absolute.
-    Therefore, the RDF graph serialized in such syntaxes is well-defined only
-    if a <a href="http://tools.ietf.org/html/rfc3986#section-5.1">base <abbr title="Internationalized Resource Identifier">IRI</abbr>
-    can be established</a> [<cite><a class="bibref" href="#bib-RFC3986">RFC3986</a></cite>].</p>
-
-      <p><strong><abbr title="Internationalized Resource Identifier">IRI</abbr> normalization:</strong>
-      Interoperability problems can be avoided by minting
-      only IRIs that are normalized according to
-      <a href="http://tools.ietf.org/html/rfc3987#section-5">Section 5</a>
-      of [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>]. Non-normalized forms that are best avoided
-      include:</p>
-
-      <ul>
-        <li>Uppercase characters in scheme names and domain names</li>
-        <li>Percent-encoding of characters where it is not
-          required by <abbr title="Internationalized Resource Identifier">IRI</abbr> syntax</li>
-        <li>Explicitly stated HTTP default port
-          (<code>http://example.com:80/</code>);
-          <code>http://example.com/</code> is preferable</li>
-        <li>Completely empty path in HTTP IRIs
-          (<code>http://example.com</code>);
-          <code>http://example.com/</code> is preferable</li>
-        <li>“<code>/./</code>” or “<code>/../</code>” in the path
-          component of an <abbr title="Internationalized Resource Identifier">IRI</abbr></li>
-        <li>Lowercase hexadecimal letters within percent-encoding
-          triplets (“<code>%3F</code>” is preferable over
-          “<code>%3f</code>”)</li>
-        <li>Punycode-encoding of Internationalized Domain Names
-          in IRIs</li>
-        <li>IRIs that are not in Unicode Normalization
-          Form C [<cite><a class="bibref" href="#bib-NFC">NFC</a></cite>]</li>
-      </ul>
-    </div></div>
-</section>
-
-
-<section id="section-Graph-Literal" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-Graph-Literal"><span class="secno">3.3 </span>Literals</h3>
-
-    <p>Literals are used for values such as strings, numbers, and dates.</p>
-
-    <p>A <dfn id="dfn-literal">literal</dfn> in an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> consists of two or three
-      elements:</p>
-
-    <ul>
-      <li>a <dfn id="dfn-lexical-form">lexical form</dfn>, being a Unicode [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] string,
-        which <em class="rfc2119" title="SHOULD">SHOULD</em> be in Normal Form C [<cite><a class="bibref" href="#bib-NFC">NFC</a></cite>],</li>
-      <li>a <dfn id="dfn-datatype-iri">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>, being an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>
-        identifying a datatype that determines how the lexical form maps
-        to a <a href="#dfn-literal-value" class="internalDFN">literal value</a>, and</li>
-      <li>if and only if the <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> is
-        <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#langString</code>, a
-        non-empty <dfn id="dfn-language-tag">language tag</dfn> as defined by [<cite><a class="bibref" href="#bib-BCP47">BCP47</a></cite>]. The
-        language tag <em class="rfc2119" title="MUST">MUST</em> be well-formed according to
-        <a href="http://tools.ietf.org/html/bcp47#section-2.2.9">section 2.2.9</a>
-        of [<cite><a class="bibref" href="#bib-BCP47">BCP47</a></cite>].</li>
-    </ul>
-
-    <p>A literal is a <dfn id="dfn-language-tagged-string">language-tagged string</dfn> if the third element
-      is present. Lexical representations of language tags <em class="rfc2119" title="MAY">MAY</em> be converted
-      to lower case. The value space of language tags is always in lower
-      case.</p>
-
-    <p>Please note that concrete syntaxes <em class="rfc2119" title="MAY">MAY</em> support
-      <dfn title="simple literal" id="dfn-simple-literal">simple literals</dfn> consisting of only a
-      <a href="#dfn-lexical-form" class="internalDFN">lexical form</a> without any <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> or <a href="#dfn-language-tag" class="internalDFN">language tag</a>.
-      Simple literals are syntactic sugar for abstract syntax
-      <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>
-      with the <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
-      <code>http://www.w3.org/2001/XMLSchema#string</code>. Similarly, most
-      concrete syntaxes represent
-      <a title="language-tagged string" href="#dfn-language-tagged-string" class="internalDFN">language-tagged strings</a> without
-      the <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> because it always equals
-      <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#langString</code>.</p>
-
-    <p>The <dfn id="dfn-literal-value">literal value</dfn> associated with a <a href="#dfn-literal" class="internalDFN">literal</a> is:</p>
-
-    <ol>
-      <li>If the literal is a <a href="#dfn-language-tagged-string" class="internalDFN">language-tagged string</a>,
-        then the literal value is a pair consisting of its <a href="#dfn-lexical-form" class="internalDFN">lexical form</a>
-        and its <a href="#dfn-language-tag" class="internalDFN">language tag</a>, in that order.</li>
-
-      <li>If the literal's <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> is in the set of
-        <a href="#dfn-recognized-datatype-iris" class="internalDFN">recognized datatype IRIs</a>, let <var>d</var> be the
-        <a href="#dfn-referent" class="internalDFN">referent</a> of the datatype <abbr title="Internationalized Resource Identifier">IRI</abbr>.
-        <ol>
-          <li>If the literal's <a href="#dfn-lexical-form" class="internalDFN">lexical form</a> is in the <a href="#dfn-lexical-space" class="internalDFN">lexical space</a>
-            of <var>d</var>, then the literal value is the result of applying
-            the <a href="#dfn-lexical-to-value-mapping" class="internalDFN">lexical-to-value mapping</a> of <var>d</var> to the
-            <a href="#dfn-lexical-form" class="internalDFN">lexical form</a>.</li>
-          <li>Otherwise, the literal is ill-typed and no literal value can be
-             associated with the literal. Such a case produces a semantic
-             inconsistency but is not <em>syntactically</em> ill-formed.
-             Implementations <em class="rfc2119" title="MUST">MUST</em> accept ill-typed literals and produce RDF
-             graphs from them. Implementations <em class="rfc2119" title="MAY">MAY</em> produce warnings when
-             encountering ill-typed literals.</li>
-        </ol>
-      </li>
-      <li>If the literal's <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> is <em>not</em> in the set of
-        <a href="#dfn-recognized-datatype-iris" class="internalDFN">recognized datatype IRIs</a>, then the literal value is
-        not defined by this specification.</li>
-    </ol>
-
-    <p><dfn id="dfn-literal-term-equality">Literal term equality</dfn>: Two literals are term-equal (the same
-      RDF literal) if and only if the two <a title="lexical form" href="#dfn-lexical-form" class="internalDFN">lexical forms</a>,
-      the two <a title="datatype IRI" href="#dfn-datatype-iri" class="internalDFN">datatype IRIs</a>, and the two
-      <a title="language tag" href="#dfn-language-tag" class="internalDFN">language tags</a> (if any) compare equal,
-      character by character. Thus, two literals can have the same value
-      without being the same RDF term. For example:</p>
-
-    <pre>      &quot;1&quot;^^xs:integer
-      &quot;01&quot;^^xs:integer
-    </pre>
-
-    <p>denote the same <a title="literal value" href="#dfn-literal-value" class="internalDFN">value</a>, but are not the
-      same literal <a title="RDF Term" href="#dfn-rdf-term" class="internalDFN">RDF terms</a> and are not
-      <a title="literal term equality" href="#dfn-literal-term-equality" class="internalDFN">term-equal</a> because their
-      <a href="#dfn-lexical-form" class="internalDFN">lexical form</a> differs.</p>
-</section>
-
-
-<section id="section-blank-nodes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-blank-nodes"><span class="secno">3.4 </span>Blank Nodes</h3>
-
-    <p><dfn title="blank node" id="dfn-blank-node">Blank nodes</dfn> are disjoint from
-    <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> and <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>.  Otherwise,
-    the set of possible blank nodes is arbitrary.  RDF makes no reference to
-    any internal structure of blank nodes.</p>
-
-    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_2"><span>Note</span></div><p id="note-bnode-id" class="">
-    <dfn title="blank node identifier" id="dfn-blank-node-identifier">Blank node identifiers</dfn>
-    are local identifiers that are used in some
-    <a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">concrete RDF syntaxes</a>
-    or RDF store implementations.
-    They are always locally scoped to the file or RDF store,
-    and are <em>not</em> persistent or portable identifiers
-    for blank nodes. Blank node identifiers are <em>not</em>
-    part of the RDF abstract syntax, but are entirely dependent
-    on the concrete syntax or implementation. The syntactic restrictions
-    on blank node identifiers, if any, therefore also depend on
-    the concrete RDF syntax or implementation.  Implementations that handle blank node
-    identifiers in concrete syntaxes need to be careful not to create the
-    same blank node from multiple occurrences of the same blank node identifier
-    except in situations where this is supported by the syntax.</p></div>
-</section>
-
-
-<section id="section-skolemization" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-skolemization"><span class="secno">3.5 </span>Replacing Blank Nodes with IRIs</h3>
-
-    <p>Blank nodes do not have identifiers in the RDF abstract syntax. The
-    <a title="blank node identifier" href="#dfn-blank-node-identifier" class="internalDFN">blank node identifiers</a> introduced
-    by some concrete syntaxes have only
-    local scope and are purely an artifact of the serialization.</p>
-
-    <p>In situations where stronger identification is needed, systems <em class="rfc2119" title="MAY">MAY</em>
-    systematically replace some or all of the blank nodes in an RDF graph
-    with <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>.  Systems wishing to do this <em class="rfc2119" title="SHOULD">SHOULD</em>
-    mint a new, globally
-    unique <abbr title="Internationalized Resource Identifier">IRI</abbr> (a <dfn id="dfn-skolem-iri">Skolem <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>) for each blank node so replaced.</p>
-
-    <p>This transformation does not appreciably change the meaning of an
-    RDF graph, provided that the Skolem IRIs do not occur anywhere else.
-    It does however permit the possibility of other graphs
-    subsequently using the Skolem IRIs, which is not possible
-    for blank nodes.</p>
-
-    <p>Systems may wish to mint Skolem IRIs in such a way that they can
-    recognize the IRIs as having been introduced solely to replace blank
-    nodes. This allows a system to map IRIs back to blank nodes
-    if needed.</p>
-
-    <p>Systems that want Skolem IRIs to be recognizable outside of the system
-    boundaries <em class="rfc2119" title="SHOULD">SHOULD</em> use a well-known <abbr title="Internationalized Resource Identifier">IRI</abbr> [<cite><a class="bibref" href="#bib-RFC5785">RFC5785</a></cite>] with the registered
-    name <code>genid</code>. This is an <abbr title="Internationalized Resource Identifier">IRI</abbr> that uses the HTTP or HTTPS scheme,
-    or another scheme that has been specified to use well-known IRIs; and whose
-    path component starts with <code>/.well-known/genid/</code>.
-
-    </p><p>For example, the authority responsible for the domain
-    <code>example.com</code> could mint the following recognizable Skolem <abbr title="Internationalized Resource Identifier">IRI</abbr>:</p>
-
-    <pre>http://example.com/.well-known/genid/d26a2d0e98334696f4ad70a677abc1f6</pre>
-
-    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_3"><span>Note</span></div><p class="">RFC 5785 [<cite><a class="bibref" href="#bib-RFC5785">RFC5785</a></cite>] only specifies well-known URIs,
-    not IRIs. For the purpose of this document, a well-known <abbr title="Internationalized Resource Identifier">IRI</abbr> is any
-    <abbr title="Internationalized Resource Identifier">IRI</abbr> that results in a well-known <abbr title="Uniform Resource Identifier">URI</abbr> after <abbr title="Internationalized Resource Identifier">IRI</abbr>-to-<abbr title="Uniform Resource Identifier">URI</abbr> mapping [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>].</p></div>
-</section>
-
-
-<section id="graph-isomorphism" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_graph-isomorphism"><span class="secno">3.6 </span>Graph Comparison</h3>
-
-    <p id="section-graph-equality">Two
-    <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a> <var>G</var> and <var>G'</var> are
-    <dfn title="graph isomorphism" id="dfn-graph-isomorphism">isomorphic</dfn> (that is, they have an identical
-    form) if there is a bijection <var>M</var> between the sets of nodes of the two
-    graphs, such that:</p>
-
-    <ol>
-      <li><var>M</var> maps blank nodes to blank nodes.</li>
-      <li><var>M(lit)=lit</var> for all <a title="literal" href="#dfn-literal" class="internalDFN">RDF literals</a> <var>lit</var> which
-      are nodes of <var>G</var>.</li>
-
-      <li><var>M(iri)=iri</var> for all <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> <var>iri</var>
-      which are nodes of <var>G</var>.</li>
-
-      <li>The triple <var>( s, p, o )</var> is in <var>G</var> if and
-      only if the triple <var>( M(s), p, M(o) )</var> is in
-      <var>G'</var></li>
-    </ol>
-
-    <p>See also: <a href="#dfn-iri-equality" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr> equality</a>, <a href="#dfn-literal-term-equality" class="internalDFN">literal term equality</a>.</p>
-
-    <p>With this definition, <var>M</var> shows how each blank node
-    in <var>G</var> can be replaced with
-    a new blank node to give <var>G'</var>. Graph isomorphism
-    is needed to support the RDF Test Cases [<cite><a class="bibref" href="#bib-RDF11-TESTCASES">RDF11-TESTCASES</a></cite>] specification.</p>
-</section>
-
-</section>
-
-
-<section id="section-dataset" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_section-dataset"><span class="secno">4. </span>RDF Datasets</h2>
-
-    <p>An <dfn id="dfn-rdf-dataset">RDF dataset</dfn> is a collection of
-      <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>, and comprises:</p>
-
-    <ul>
-      <li>Exactly one <dfn id="dfn-default-graph">default graph</dfn>, being an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>.
-        The default graph does not have a name and <em class="rfc2119" title="MAY">MAY</em> be empty.</li>
-      <li>Zero or more <dfn title="named graph" id="dfn-named-graph">named graphs</dfn>.
-        Each named graph is a pair consisting of an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a blank node
-        (the <dfn id="dfn-graph-name">graph name</dfn>), and an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>.
-        Graph names are unique within an RDF dataset.</li>
-    </ul>
-
-    <p><a title="blank node" href="#dfn-blank-node" class="internalDFN">Blank nodes</a> can be shared between graphs
-      in an <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a>.</p>
-
-    <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_4"><span>Note</span></div><div id="note-datasets" class="">
-      <p>Despite the use of the word “name” in “<a href="#dfn-named-graph" class="internalDFN">named graph</a>”, the
-        <a href="#dfn-graph-name" class="internalDFN">graph name</a> is not required to <a href="#dfn-denote" class="internalDFN">denote</a> the graph. It is
-        merely syntactically paired with the graph. RDF does not place any
-        formal restrictions on what <a href="#dfn-resource" class="internalDFN">resource</a> the graph name may denote,
-        nor on the relationship between that resource and the graph.
-        A discussion of different RDF dataset semantics can be found in
-        [<cite><a class="bibref" href="#bib-RDF11-DATASETS">RDF11-DATASETS</a></cite>].</p>
-
-      <p>Some <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a> implementations do not
-        track empty <a title="named graph" href="#dfn-named-graph" class="internalDFN">named graphs</a>. Applications
-        can avoid interoperability issues by not ascribing importance to
-        the presence or absence of empty named graphs.</p>
-
-      <p>SPARQL 1.1 [<cite><a class="bibref" href="#bib-SPARQL11-OVERVIEW">SPARQL11-OVERVIEW</a></cite>] also defines the concept of an RDF
-				Dataset.  The definition of an RDF Dataset in SPARQL 1.1 and this
-				specification differ slightly in that this specification allows RDF
-				Graphs to be identified using either an <abbr title="Internationalized Resource Identifier">IRI</abbr> or a blank node.  SPARQL 1.1
-				Query Language only allows RDF Graphs to be identified using an <abbr title="Internationalized Resource Identifier">IRI</abbr>.
-				Existing SPARQL implementations might not allow blank nodes to be used
-				to identify RDF Graphs for some time, so their use can cause
-				interoperability problems.
-        <a href="#section-skolemization">Skolemizing</a> blank nodes used as
-        graph names can be used to overcome these interoperability problems.</p>
-    </div></div>
-
-<section id="section-dataset-isomorphism" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-dataset-isomorphism"><span class="secno">4.1 </span>RDF Dataset Comparison</h3>
-
-    <p id="section-dataset-equality">Two <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF datasets</a>
-      (the RDF dataset <var>D1</var> with default graph <var>DG1</var> and any named
-      graph <var>NG1</var> and the RDF dataset <var>D2</var> with default graph
-      <var>DG2</var> and any named graph <var>NG2</var>)
-      are <dfn title="dataset isomorphism" id="dfn-dataset-isomorphism">dataset-isomorphic</dfn> if and only if
-      there is a bijection <var>M</var> between the nodes, triples and graphs in
-      <var>D1</var> and those in <var>D2</var> such that:</p>
-
-    <ol>
-      <li><var>M</var> maps blank nodes to blank nodes;</li>
-      <li><var>M</var> is the identity map on literals and URIs;</li>
-      <li>For every triple &lt;s p o&gt;, <var>M</var>(&lt;s, p, o&gt;)=
-        &lt;<var>M(s)</var>, <var>M(p)</var>, <var>M(o)</var>&gt;;</li>
-      <li>For every graph <var>G</var>={t1, ..., tn},
-        <var>M(G)</var>={<var>M(t1)</var>, ..., <var>M(tn)</var>};</li>
-      <li><var>DG2</var> = <var>M(DG1)</var>; and</li>
-      <li>&lt;n, G&gt; is in <var>NG1</var> if and only if
-        &lt;<var>M(n)</var>, <var>M(G)</var>&gt; is in <var>NG2</var>.
-    </li></ol>
-
-</section>
-
-<section class="informative" id="section-dataset-conneg" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-dataset-conneg"><span class="secno">4.2 </span>Content Negotiation of RDF Datasets</h3><p><em>This section is non-normative.</em></p>
-
-    <p>Web resources may have multiple representations that are made available via
-    <a href="http://www.w3.org/TR/webarch/#frag-coneg">content negotiation</a>
-    [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>].  A representation may be returned in an RDF serialization
-    format that supports the expression of both <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF datasets</a> and
-    <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>.  If an <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a>
-    is returned and the consumer is expecting an <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>,
-    the consumer is expected to use the <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF dataset's</a> default graph.</p>
-
-</section>
-
-</section>
-
-
-<section id="section-Datatypes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_section-Datatypes"><span class="secno">5. </span>Datatypes</h2>
-
-    <p>Datatypes are used with RDF <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>
-    to represent values such as strings, numbers and dates.
-    The datatype abstraction used in RDF is compatible with XML Schema
-    [<cite><a class="bibref" href="#bib-XMLSCHEMA11-2">XMLSCHEMA11-2</a></cite>]. Any datatype definition that conforms
-    to this abstraction <em class="rfc2119" title="MAY">MAY</em> be used in RDF, even if not defined
-    in terms of XML Schema. RDF re-uses many of the XML Schema
-    built-in datatypes, and defines two additional non-normative datatypes,
-    <code><a href="#dfn-rdf-html" class="internalDFN">rdf:HTML</a></code> and <code><a href="#dfn-rdf-xmlliteral" class="internalDFN">rdf:XMLLiteral</a></code>.
-    The list of datatypes supported by an implementation is determined
-    by its <a href="#dfn-recognized-datatype-iris" class="internalDFN">recognized datatype IRIs</a>.</p>
-
-    <p>A <dfn id="dfn-datatype">datatype</dfn> consists of a <a href="#dfn-lexical-space" class="internalDFN">lexical space</a>,
-    a <a href="#dfn-value-space" class="internalDFN">value space</a> and a <a href="#dfn-lexical-to-value-mapping" class="internalDFN">lexical-to-value mapping</a>, and
-    is denoted by one or more <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>.</p>
-
-<p>The <dfn id="dfn-lexical-space">lexical space</dfn> of a datatype is a set of Unicode [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] strings.</p>
-
-    <p>The <dfn id="dfn-lexical-to-value-mapping">lexical-to-value mapping</dfn> of a datatype is a set of
-    pairs whose first element belongs to the <a href="#dfn-lexical-space" class="internalDFN">lexical space</a>,
-    and the second element belongs to the <dfn id="dfn-value-space">value space</dfn>
-    of the datatype. Each member of the lexical space is paired with exactly
-    one value, and is a <em>lexical representation</em>
-    of that value. The mapping can be seen as a function
-    from the lexical space to the value space.</p>
-
-    <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_5"><span>Note</span></div><p class=""><a title="language-tagged string" href="#dfn-language-tagged-string" class="internalDFN">Language-tagged
-    strings</a> have the <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
-    <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#langString</code>.
-    No datatype is formally defined for this <abbr title="Internationalized Resource Identifier">IRI</abbr> because the definition
-    of <a title="datatype" href="#dfn-datatype" class="internalDFN">datatypes</a> does not accommodate
-    <a title="language tag" href="#dfn-language-tag" class="internalDFN">language tags</a> in the <a href="#dfn-lexical-space" class="internalDFN">lexical space</a>.
-    The <a href="#dfn-value-space" class="internalDFN">value space</a> associated with this datatype <abbr title="Internationalized Resource Identifier">IRI</abbr> is the set
-    of all pairs of strings and language tags.</p></div>
-
-    <p>For example, the XML Schema datatype <code>xsd:boolean</code>,
-    where each member of the <a href="#dfn-value-space" class="internalDFN">value space</a> has two lexical
-    representations, is defined as follows:</p>
-
-    <dl>
-    <dt>Lexical space:</dt>
-    <dd>{“<code>true</code>”, “<code>false</code>”, “<code>1</code>”, “<code>0</code>”}</dd>
-    <dt>Value space:</dt>
-    <dd>{<em><strong>true</strong></em>, <em><strong>false</strong></em>}</dd>
-    <dt>Lexical-to-value mapping</dt>
-    <dd>{
-        &lt;“<code>true</code>”, <em><strong>true</strong></em>&gt;,
-        &lt;“<code>false</code>”, <em><strong>false</strong></em>&gt;,
-        &lt;“<code>1</code>”, <em><strong>true</strong></em>&gt;,
-        &lt;“<code>0</code>”, <em><strong>false</strong></em>&gt;,
-        }</dd>
-    </dl>
-
-    <p>The <a title="literal" href="#dfn-literal" class="internalDFN">literals</a> that can be defined using this
-    datatype are:</p>
-
-    <table class="simple">
-      <caption>This table lists the literals of type xsd:boolean.</caption>
-      <tbody><tr>
-        <th>Literal</th>
-        <th>Value</th>
-      </tr>
-      <tr>
-        <td>&lt;“<code>true</code>”, <code>xsd:boolean</code>&gt;</td>
-        <td><em><strong>true</strong></em></td>
-      </tr>
-      <tr>
-        <td>&lt;“<code>false</code>”, <code>xsd:boolean</code>&gt;</td>
-        <td><em><strong>false</strong></em></td>
-      </tr>
-      <tr>
-        <td>&lt;“<code>1</code>”, <code>xsd:boolean</code>&gt;</td>
-        <td><em><strong>true</strong></em></td>
-      </tr>
-      <tr>
-        <td>&lt;“<code>0</code>”, <code>xsd:boolean</code>&gt;</td>
-        <td><em><strong>false</strong></em></td>
-      </tr>
-    </tbody></table>
-
-
-<section id="xsd-datatypes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_xsd-datatypes"><span class="secno">5.1 </span>The XML Schema Built-in Datatypes</h3>
-
-    <p><a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> of the form
-    <code>http://www.w3.org/2001/XMLSchema#<em>xxx</em></code>,
-    where <code><em>xxx</em></code>
-    is the name of a datatype, denote the built-in datatypes defined in
-    <em><a href="http://www.w3.org/TR/xmlschema11-2/">XML Schema 1.1 Part 2:
-    Datatypes</a></em> [<cite><a class="bibref" href="#bib-XMLSCHEMA11-2">XMLSCHEMA11-2</a></cite>]. The XML Schema built-in types
-    listed in the following table are the
-    <dfn id="dfn-rdf-compatible-xsd-types">RDF-compatible XSD types</dfn>. Their use is <em class="rfc2119" title="RECOMMENDED">RECOMMENDED</em>.</p>
-
-    <p>Readers might note that the xsd:hexBinary and xsd:base64Binary
-    datatypes are the only safe datatypes for transferring binary
-    information.</p>
-
-    <table class="simple">
-      <caption>A list of the RDF-compatible XSD types, with short descriptions&quot;</caption>
-    <tbody><tr><th></th><th>Datatype</th><th>Value space (informative)</th></tr>
-
-    <tr><th rowspan="4">Core types</th><td><a href="http://www.w3.org/TR/xmlschema11-2/#string"><code>xsd:string</code></a></td><td>Character strings (but not all Unicode character strings)</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#boolean"><code>xsd:boolean</code></a></td><td>true, false</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#decimal"><code>xsd:decimal</code></a></td><td>Arbitrary-precision decimal numbers</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#integer"><code>xsd:integer</code></a></td><td>Arbitrary-size integer numbers</td></tr>
-
-    <tr><th rowspan="2">IEEE floating-point<br />numbers</th>
-        <td><a href="http://www.w3.org/TR/xmlschema11-2/#double"><code>xsd:double</code></a></td><td>64-bit floating point numbers incl. ±Inf, ±0, NaN</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#float"><code>xsd:float</code></a></td><td>32-bit floating point numbers incl. ±Inf, ±0, NaN</td></tr>
-
-    <tr><th rowspan="4">Time and date</th>
-        <td><a href="http://www.w3.org/TR/xmlschema11-2/#date"><code>xsd:date</code></a></td><td>Dates (yyyy-mm-dd) with or without timezone</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#time"><code>xsd:time</code></a></td><td>Times (hh:mm:ss.sss…) with or without timezone</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#dateTime"><code>xsd:dateTime</code></a></td><td>Date and time with or without timezone</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#dateTimeStamp"><code>xsd:dateTimeStamp</code></a></td><td>Date and time with required timezone</td></tr>
-
-    <tr><th rowspan="8">Recurring and<br />partial dates</th>
-        <td><a href="http://www.w3.org/TR/xmlschema11-2/#gYear"><code>xsd:gYear</code></a></td><td>Gregorian calendar year</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#gMonth"><code>xsd:gMonth</code></a></td><td>Gregorian calendar month</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#gDay"><code>xsd:gDay</code></a></td><td>Gregorian calendar day of the month</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#gYearMonth"><code>xsd:gYearMonth</code></a></td><td>Gregorian calendar year and month</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#gMonthDay"><code>xsd:gMonthDay</code></a></td><td>Gregorian calendar month and day</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#duration"><code>xsd:duration</code></a></td><td>Duration of time</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#yearMonthDuration"><code>xsd:yearMonthDuration</code></a></td><td>Duration of time (months and years only)</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#dayTimeDuration"><code>xsd:dayTimeDuration</code></a></td><td>Duration of time (days, hours, minutes, seconds only)</td></tr>
-
-    <tr><th rowspan="12">Limited-range<br />integer numbers</th>
-        <td><a href="http://www.w3.org/TR/xmlschema11-2/#byte"><code>xsd:byte</code></a></td><td>-128…+127 (8 bit)</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#short"><code>xsd:short</code></a></td><td>-32768…+32767 (16 bit)</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#int"><code>xsd:int</code></a></td><td>-2147483648…+2147483647 (32 bit)</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#long"><code>xsd:long</code></a></td><td>-9223372036854775808…+9223372036854775807 (64 bit)</td></tr>
-
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#unsignedByte"><code>xsd:unsignedByte</code></a></td><td>0…255 (8 bit)</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#unsignedShort"><code>xsd:unsignedShort</code></a></td><td>0…65535 (16 bit)</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#unsignedInt"><code>xsd:unsignedInt</code></a></td><td>0…4294967295 (32 bit)</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#unsignedLong"><code>xsd:unsignedLong</code></a></td><td>0…18446744073709551615 (64 bit)</td></tr>
-
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#positiveInteger"><code>xsd:positiveInteger</code></a></td><td>Integer numbers &gt;0</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#nonNegativeInteger"><code>xsd:nonNegativeInteger</code></a></td><td>Integer numbers ≥0</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#negativeInteger"><code>xsd:negativeInteger</code></a></td><td>Integer numbers &lt;0</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#nonPositiveInteger"><code>xsd:nonPositiveInteger</code></a></td><td>Integer numbers ≤0</td></tr>
-
-    <tr><th rowspan="2">Encoded binary data</th>
-        <td><a href="http://www.w3.org/TR/xmlschema11-2/#hexBinary"><code>xsd:hexBinary</code></a></td><td>Hex-encoded binary data</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#base64Binary"><code>xsd:base64Binary</code></a></td><td>Base64-encoded binary data</td></tr>
-
-    <tr><th rowspan="7">Miscellaneous<br />XSD types</th>
-        <td><a href="http://www.w3.org/TR/xmlschema11-2/#anyURI"><code>xsd:anyURI</code></a></td><td>Absolute or relative URIs and IRIs</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#language"><code>xsd:language</code></a></td><td>Language tags per [<cite><a class="bibref" href="#bib-BCP47">BCP47</a></cite>]</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#normalizedString"><code>xsd:normalizedString</code></a></td><td>Whitespace-normalized strings</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#token"><code>xsd:token</code></a></td><td>Tokenized strings</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#NMTOKEN"><code>xsd:NMTOKEN</code></a></td><td>XML NMTOKENs</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#Name"><code>xsd:Name</code></a></td><td>XML Names</td></tr>
-    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#NCName"><code>xsd:NCName</code></a></td><td>XML NCNames</td></tr>
-    </tbody></table>
-
-    <p>The other built-in XML Schema datatypes are unsuitable
-      for various reasons and <em class="rfc2119" title="SHOULD NOT">SHOULD NOT</em> be used:</p>
-
-    <ul>
-      <li><a href="http://www.w3.org/TR/xmlschema11-2/#QName"><code>xsd:QName</code></a>
-        and <a href="http://www.w3.org/TR/xmlschema11-2/#ENTITY"><code>xsd:ENTITY</code></a>
-        require an enclosing XML document context.</li>
-      <li><a href="http://www.w3.org/TR/xmlschema11-2/#ID"><code>xsd:ID</code></a>
-        and <a href="http://www.w3.org/TR/xmlschema11-2/#IDREF"><code>xsd:IDREF</code></a>
-        are for cross references within an XML document.</li>
-      <li><a href="http://www.w3.org/TR/xmlschema11-2/#NOTATION"><code>xsd:NOTATION</code></a>
-        is not intended for direct use.</li>
-      <li><a href="http://www.w3.org/TR/xmlschema11-2/#IDREFS"><code>xsd:IDREFS</code></a>,
-        <a href="http://www.w3.org/TR/xmlschema11-2/#ENTITIES"><code>xsd:ENTITIES</code></a>
-        and <a href="http://www.w3.org/TR/xmlschema11-2/#NMTOKENS"><code>xsd:NMTOKENS</code></a>
-        are sequence-valued datatypes which do not fit the RDF <a href="#dfn-datatype" class="internalDFN">datatype</a>
-        model.</li>
-    </ul>
-
-</section>
-
-
-<section class="informative" id="section-html" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-html"><span class="secno">5.2 </span>The <code>rdf:HTML</code> Datatype</h3><p><em>This section is non-normative.</em></p>
-
-    <p>RDF provides for HTML content as a possible <a href="#dfn-literal-value" class="internalDFN">literal value</a>.
-      This allows markup in literal values. Such content is indicated
-      in an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> using a <a href="#dfn-literal" class="internalDFN">literal</a> whose <a href="#dfn-datatype" class="internalDFN">datatype</a>
-      is set to <code><dfn id="dfn-rdf-html">rdf:HTML</dfn></code>. This datatype is defined
-      as non-normative because it depends on [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>], a specification that
-      has not yet reached <abbr title="World Wide Web Consortium">W3C</abbr> Recommendation status.</p>
-
-    <p>The <code>rdf:HTML</code> datatype is defined as follows:</p>
-
-    <dl>
-      <dt>The <abbr title="Internationalized Resource Identifier">IRI</abbr> denoting this datatype</dt>
-      <dd>is <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#HTML</code>.</dd>
-
-      <dt>The lexical space</dt>
-      <dd>is the set of Unicode [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] strings.</dd>
-
-      <dt>The value space</dt>
-      <dd>is a set of DOM
-        <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
-        nodes [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>]. Two
-        <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
-        nodes <em>A</em> and <em>B</em> are considered equal if and only if
-        the DOM method
-        <code><em>A</em>.<a href="http://www.w3.org/TR/dom/#dom-node-isequalnode">isEqualNode</a>(<em>B</em>)</code>
-        [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>] returns <code>true</code>.</dd>
-
-      <dt>The lexical-to-value mapping</dt>
-      <dd>
-        <p>Each member of the lexical space is associated with the result
-          of applying the following algorithm:</p>
-        <ul>
-          <li>Let <code>domnodes</code> be the list of <a href="http://www.w3.org/TR/dom/#node">DOM nodes</a> [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>]
-            that result from applying the
-            <a href="http://www.w3.org/TR/html5/syntax.html#parsing-html-fragments">HTML fragment parsing algorithm</a> [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>]
-            to the input string, without a context element.</li>
-          <li>Let <code>domfrag</code> be a DOM
-            <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a> [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>]
-            whose <code>childNodes</code> attribute is equal to <code>domnodes</code></li>
-            <li>Return <code>domfrag.<a href="http://www.w3.org/TR/dom/#dom-node-normalize">normalize</a>()</code></li>
-        </ul>
-      </dd>
-    </dl>
-
-    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_6"><span>Note</span></div><p id="note-html" class="">
-      Any language annotation (<code>lang=&quot;…&quot;</code>) or
-      XML namespaces (<code>xmlns</code>) desired in the HTML content
-      must be included explicitly in the HTML literal. Relative URLs
-      in attributes such as <code>href</code> do not have a well-defined
-      base URL and are best avoided.
-      RDF applications may use additional equivalence relations,
-      such as that which relates an <code>xsd:string</code> with an
-      <code>rdf:HTML</code> literal corresponding to a single text node
-      of the same string.</p></div>
-</section>
-
-<section class="informative" id="section-XMLLiteral" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    <h3 aria-level="2" role="heading" id="h3_section-XMLLiteral"><span class="secno">5.3 </span>The <code>rdf:XMLLiteral</code> Datatype</h3><p><em>This section is non-normative.</em></p>
-
-    <p>RDF provides for XML content as a possible <a href="#dfn-literal-value" class="internalDFN">literal value</a>.
-      Such content is indicated in an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> using a <a href="#dfn-literal" class="internalDFN">literal</a>
-      whose <a href="#dfn-datatype" class="internalDFN">datatype</a> is set to <code><dfn id="dfn-rdf-xmlliteral">rdf:XMLLiteral</dfn></code>.
-      This datatype is defined as non-normative because it depends on [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>],
-      a specification that has not yet reached <abbr title="World Wide Web Consortium">W3C</abbr> Recommendation status.</p>
-
-    <p>The <code>rdf:XMLLiteral</code> datatype is defined as follows:</p>
-
-    <dl>
-      <dt id="XMLLiteral-uri">The <abbr title="Internationalized Resource Identifier">IRI</abbr> denoting this <a href="#dfn-datatype" class="internalDFN">datatype</a></dt>
-      <dd>is <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>.</dd>
-
-      <dt id="XMLLiteral-lexical-space">The <a href="#dfn-lexical-space" class="internalDFN">lexical space</a></dt>
-      <dd>is the set of all strings which are well-balanced, self-contained
-        <a href="http://www.w3.org/TR/2000/REC-xml-20001006#NT-content">XML content</a>
-        [<cite><a class="bibref" href="#bib-XML10">XML10</a></cite>]; and for which embedding between an arbitrary
-        XML start tag and an end tag yields a document conforming to
-        <a href="http://www.w3.org/TR/1999/REC-xml-names-19990114/">XML Namespaces</a>
-        [<cite><a class="bibref" href="#bib-XML-NAMES">XML-NAMES</a></cite>].</dd>
-
-      <dt id="XMLLiteral-value-space">The <a href="#dfn-value-space" class="internalDFN">value space</a></dt>
-        <dd>is a set of DOM
-        <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
-        nodes [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>]. Two
-        <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
-        nodes <em>A</em> and <em>B</em> are considered equal if and only if the DOM method
-        <code><em>A</em>.<a href="http://www.w3.org/TR/dom/#dom-node-isequalnode">isEqualNode</a>(<em>B</em>)</code>
-        returns <code>true</code>.</dd>
-
-      <dt id="XMLLiteral-mapping">The <a href="#dfn-lexical-to-value-mapping" class="internalDFN">lexical-to-value mapping</a></dt>
-      <dd>
-        <p>Each member of the lexical space is associated with the result of applying the following algorithm:</p>
-        <ul>
-          <li>Let <code>domfrag</code> be a DOM
-            <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
-            node [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>] corresponding to the input string</li>
-          <li>Return <code>domfrag.<a href="http://www.w3.org/TR/dom/#dom-node-normalize">normalize</a>()</code></li>
-        </ul>
-      </dd>
-
-      <dt id="XMLLiteral-canonical">The canonical mapping</dt>
-      <dd>defines a
-        <a href="http://www.w3.org/TR/xmlschema11-2/#dt-canonical-mapping">canonical lexical form</a> [<cite><a class="bibref" href="#bib-XMLSCHEMA11-2">XMLSCHEMA11-2</a></cite>]
-        for each member of the value space. The <code>rdf:XMLLiteral</code> canonical mapping is the
-        <a href="http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718/#def-exclusive-XML-canonicalization-method">exclusive XML canonicalization method</a>
-        (<em>with comments, with empty
-        <a href="http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718/#def-InclusiveNamespaces-PrefixList">InclusiveNamespaces PrefixList</a></em>)
-        [<cite><a class="bibref" href="#bib-XML-EXC-C14N">XML-EXC-C14N</a></cite>].</dd>
-    </dl>
-
-    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_7"><span>Note</span></div><p class="">Any XML namespace declarations (<code>xmlns</code>),
-      language annotation (<code>xml:lang</code>) or base <abbr title="Uniform Resource Identifier">URI</abbr> declarations
-      (<code>xml:base</code>) desired in the XML content must be included
-      explicitly in the XML literal. Note that some concrete RDF syntaxes
-      may define mechanisms for inheriting them from the context (e.g.,
-      <a href="http://www.w3.org/TR/rdf-syntax-grammar/#parseTypeLiteralPropertyElt"><code>@parseType=&quot;literal&quot;</code></a>
-      in RDF/XML [<cite><a class="bibref" href="#bib-RDF11-XML">RDF11-XML</a></cite>]).</p></div>
-</section>
-
-<section id="datatype-iris">
-    <h3 aria-level="2" role="heading" id="h3_datatype-iris"><span class="secno">5.4 </span>Datatype IRIs</h3>
-
-    <p>Datatypes are identified by <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>. If
-      <var>D</var> is a set of IRIs which are used to refer to
-      datatypes, then the elements of <var>D</var> are called <dfn id="dfn-recognized-datatype-iris">recognized
-      datatype IRIs</dfn>. Recognized IRIs have fixed
-      <a href="#referents">referents</a>. If any <abbr title="Internationalized Resource Identifier">IRI</abbr> of the form
-      <code>http://www.w3.org/2001/XMLSchema#xxx</code> is recognized, it
-      <em class="rfc2119" title="MUST">MUST</em> refer to the RDF-compatible XSD type named <code>xsd:xxx</code> for
-      every XSD type listed in <a href="#xsd-datatypes">section 5.1</a>.
-      Furthermore, the following IRIs are allocated for non-normative
-      datatypes:
-
-    </p><ul>
-      <li>The <abbr title="Internationalized Resource Identifier">IRI</abbr> <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>
-        refers to the datatype <code><a href="#dfn-rdf-xmlliteral" class="internalDFN">rdf:XMLLiteral</a></code></li>
-      <li>The <abbr title="Internationalized Resource Identifier">IRI</abbr> <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#HTML</code>
-        refers to the datatype <code><a href="#dfn-rdf-html" class="internalDFN">rdf:HTML</a></code></li>
-    </ul>
-
-    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_8"><span>Note</span></div><p class="">Semantic extensions of RDF might choose to
-      recognize other datatype IRIs
-      and require them to refer to a fixed datatype.  See the RDF
-      Semantics specification [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>] for more information on
-      semantic extensions.</p></div>
-
-    <p>RDF processors are not required to recognize datatype IRIs.
-      Any literal typed with an unrecognized <abbr title="Internationalized Resource Identifier">IRI</abbr> is treated just like
-      an unknown <abbr title="Internationalized Resource Identifier">IRI</abbr>, i.e. as referring to an unknown thing. Applications
-      <em class="rfc2119" title="MAY">MAY</em> give a warning message if they are unable to determine the
-      referent of an <abbr title="Internationalized Resource Identifier">IRI</abbr> used in a typed literal, but they <em class="rfc2119" title="SHOULD NOT">SHOULD NOT</em>
-      reject such RDF as either a syntactic or semantic error.</p><p>
-
-    </p><p>Other specifications <em class="rfc2119" title="MAY">MAY</em> impose additional constraints on
-      <a title="datatype IRI" href="#dfn-datatype-iri" class="internalDFN">datatype IRIs</a>, for example, require support
-      for certain datatypes.</p>
-
-    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_9"><span>Note</span></div><p id="note-custom-datatypes" class="">The Web Ontology Language
-      [<cite><a class="bibref" href="#bib-OWL2-OVERVIEW">OWL2-OVERVIEW</a></cite>] offers facilities for formally defining
-      <a href="http://www.w3.org/TR/owl2-syntax/#Datatype_Definitions">custom
-      datatypes</a> that can be used with RDF. Furthermore, a practice for
-      identifying
-      <a href="http://www.w3.org/TR/swbp-xsch-datatypes/#sec-userDefined">
-      user-defined simple XML Schema datatypes</a>
-      is suggested in [<cite><a class="bibref" href="#bib-SWBP-XSCH-DATATYPES">SWBP-XSCH-DATATYPES</a></cite>]. RDF implementations
-      are not required to support either of these facilities.</p></div>
-</section>
-
-</section>
-
-
-<section class="informative" id="section-fragID" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-  
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_section-fragID"><span class="secno">6. </span>Fragment Identifiers</h2><p><em>This section is non-normative.</em></p>
-
-  <p>RDF uses <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>, which may include
-    <dfn id="dfn-fragment-identifiers">fragment identifiers</dfn>, as resource identifiers.
-    The semantics of fragment identifiers is
-    <a href="http://tools.ietf.org/html/rfc3986#section-3.5">defined in
-    RFC 3986</a> [<cite><a class="bibref" href="#bib-RFC3986">RFC3986</a></cite>]: They identify a secondary resource
-    that is usually a part of, view of, defined in, or described in
-    the primary resource, and the precise semantics depend on the set
-    of representations that might result from a retrieval action
-    on the primary resource.</p>
-
-  <p>This section discusses the handling of fragment identifiers
-    in representations that encode <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>.</p>
-
-  <p>In RDF-bearing representations of a primary resource
-    <code>&lt;foo&gt;</code>,
-    the secondary resource identified by a fragment <code>bar</code>
-    is the <a href="#dfn-resource" class="internalDFN">resource</a> <a title="denote" href="#dfn-denote" class="internalDFN">denoted</a> by the
-    full <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> <code>&lt;foo#bar&gt;</code> in the <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>.
-    Since IRIs in RDF graphs can denote anything, this can be
-    something external to the representation, or even external
-    to the web.</p>
-
-  <p>In this way, the RDF-bearing representation acts as an intermediary
-    between the web-accessible primary resource, and some set of possibly
-    non-web or abstract entities that the <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> may describe.</p>
-
-  <p>In cases where other specifications constrain the semantics of
-    fragment identifiers in RDF-bearing representations, the encoded
-    <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> should use fragment identifiers in a way that is consistent
-    with these constraints. For example, in an HTML+RDFa document [<cite><a class="bibref" href="#bib-HTML-RDFA">HTML-RDFA</a></cite>],
-    the fragment <code>chapter1</code> may identify a document section
-    via the semantics of HTML's <code>@name</code> or <code>@id</code>
-    attributes. The <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> <code>&lt;#chapter1&gt;</code> should
-    then be taken to <a href="#dfn-denote" class="internalDFN">denote</a> that same section in any RDFa-encoded
-    <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">triples</a> within the same document.
-    Similarly, fragment identifiers should be used consistently in resources
-    with multiple representations that are made available via
-    <a href="http://www.w3.org/TR/webarch/#frag-coneg">content negotiation</a>
-    [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>]. For example, if the fragment <code>chapter1</code> identifies a
-    document section in an HTML representation of the primary resource, then the
-    <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> <code>&lt;#chapter1&gt;</code> should be taken to
-    <a href="#dfn-denote" class="internalDFN">denote</a> that same section in all RDF-bearing representations of the
-    same primary resource.</p>
-</section>
-
-<section class="informative" id="section-generalized-rdf" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_section-generalized-rdf"><span class="secno">7. </span>Generalized RDF Triples, Graphs, and Datasets</h2><p><em>This section is non-normative.</em></p>
-
-    <p>It is sometimes convenient to loosen the requirements
-    on <a href="#dfn-rdf-triple" class="internalDFN">RDF triple</a>s.  For example, the completeness
-    of the RDFS entailment rules is easier to show with a
-    generalization of RDF triples.</p>
-
-    <p>A <dfn title="generalized RDF triple" id="dfn-generalized-rdf-triple">generalized RDF
-      triple</dfn> is a triple having a subject, a predicate,
-      and object, where each can be an <a title="iri" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a
-      <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank node</a> or a
-      <a href="#dfn-literal" class="internalDFN">literal</a>. A
-      <dfn title="generalized RDF graph" id="dfn-generalized-rdf-graph">generalized RDF graph</dfn>
-      is a set of generalized RDF triples. A
-      <dfn title="generalized RDF dataset" id="dfn-generalized-rdf-dataset">generalized RDF dataset</dfn>
-      comprises a distinguished generalized RDF graph, and zero
-      or more pairs each associating an <abbr title="Internationalized Resource Identifier">IRI</abbr>, a blank node or a literal
-      to a generalized RDF graph.</p>
-
-
-    <p>Generalized RDF triples, graphs, and datasets differ
-      from normative RDF <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">triples</a>,
-      <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">graphs</a>, and
-      <a title="RDF dataset" href="#dfn-rdf-dataset" class="internalDFN">datasets</a> only
-      by allowing <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>,
-      <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a> and
-      <a title="literal" href="#dfn-literal" class="internalDFN">literals</a> to appear
-      in any position, i.e., as subject, predicate, object or graph names.</p>
-
-    <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_10"><span>Note</span></div><p id="note-generalized-rdf" class=""> Any users of
-    generalized RDF triples, graphs or datasets need to be
-    aware that these notions are non-standard extensions of
-    RDF and their use may cause interoperability problems.
-    There is no requirement on the part of any RDF tool to
-    accept, process, or produce anything beyond standard RDF
-    triples, graphs, and datasets. </p></div>
-
-</section>
-
-<section class="informative" id="section-Acknowledgments" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-  
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_section-Acknowledgments"><span class="secno">8. </span>Acknowledgments</h2><p><em>This section is non-normative.</em></p>
-
-  <p>The editors acknowledge valuable contributions from Thomas Baker,
-    Tim Berners-Lee, David Booth, Dan Brickley, Gavin Carothers, Jeremy Carroll,
-    Pierre-Antoine Champin, Dan Connolly, John Cowan, Martin J. Dürst,
-    Alex Hall, Steve Harris, Sandro Hawke, Pat Hayes, Ivan Herman, Peter F. Patel-Schneider,
-    Addison Phillips, Eric Prud'hommeaux, Nathan Rixham, Andy Seaborne, Leif Halvard Silli,
-    Guus Schreiber, Dominik Tomaszuk, and Antoine Zimmermann.</p>
-
-  <p>The membership of the RDF Working Group included Thomas Baker,
-    Scott Bauer, Dan Brickley, Gavin Carothers, Pierre-Antoine Champin,
-    Olivier Corby, Richard Cyganiak, Souripriya Das, Ian Davis, Lee Feigenbaum,
-    Fabien Gandon, Charles Greer, Alex Hall, Steve Harris, Sandro Hawke,
-    Pat Hayes, Ivan Herman, Nicholas Humfrey, Kingsley Idehen, Gregg Kellogg,
-    Markus Lanthaler, Arnaud Le Hors, Peter F. Patel-Schneider,
-    Eric Prud'hommeaux, Yves Raimond, Nathan Rixham, Guus Schreiber,
-    Andy Seaborne, Manu Sporny, Thomas Steiner, Ted Thibodeau, Mischa Tuffield,
-    William Waites, Jan Wielemaker, David Wood, Zhe Wu, and Antoine Zimmermann.</p>
-</section>
-
-
-<section id="changes" class="appendix informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-    
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_changes"><span class="secno">A. </span>Changes between RDF 1.0 and RDF 1.1</h2><p><em>This section is non-normative.</em></p>
-
-    <p>A detailed overview of the differences between RDF versions 1.0
-      and 1.1 can be found in
-      <a href="http://www.w3.org/TR/rdf11-new/">What’s New in RDF 1.1</a> [<cite><a class="bibref" href="#bib-RDF11-NEW">RDF11-NEW</a></cite>].</p>
-</section>
-
-
-<section id="change-log" class="appendix informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-  
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_change-log"><span class="secno">B. </span>Changes since Proposed Recommendation</h2><p><em>This section is non-normative.</em></p>
-  <p>No changes.</p>
-</section>
-
-  
-
-
-<section class="appendix" id="references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
-<!--OddPage-->
-<h2 aria-level="1" role="heading" id="h2_references"><span class="secno">C. </span>References</h2><section id="normative-references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h3 aria-level="2" role="heading" id="h3_normative-references"><span class="secno">C.1 </span>Normative references</h3><dl class="bibliography" about=""><dt id="bib-BCP47">[BCP47]</dt><dd rel="dcterms:requires">A. Phillips; M. Davis. <a href="http://tools.ietf.org/html/bcp47"><cite>Tags for Identifying Languages</cite></a>. September 2009. IETF Best Current Practice. URL: <a href="http://tools.ietf.org/html/bcp47">http://tools.ietf.org/html/bcp47</a>
-</dd><dt id="bib-NFC">[NFC]</dt><dd rel="dcterms:requires">M. Davis, Ken Whistler. <a href="http://www.unicode.org/reports/tr15/"><cite>TR15, Unicode Normalization Forms.</cite></a>. 17 September 2010, URL: <a href="http://www.unicode.org/reports/tr15/">http://www.unicode.org/reports/tr15/</a>
-</dd><dt id="bib-RFC2119">[RFC2119]</dt><dd rel="dcterms:requires">S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key words for use in RFCs to Indicate Requirement Levels.</cite></a> March 1997. Internet RFC 2119.  URL: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a> 
-</dd><dt id="bib-RFC3987">[RFC3987]</dt><dd rel="dcterms:requires">M. Dürst; M. Suignard. <a href="http://www.ietf.org/rfc/rfc3987.txt"><cite>Internationalized Resource Identifiers (IRIs)</cite></a>. January 2005. RFC. URL: <a href="http://www.ietf.org/rfc/rfc3987.txt">http://www.ietf.org/rfc/rfc3987.txt</a>
-</dd><dt id="bib-UNICODE">[UNICODE]</dt><dd rel="dcterms:requires"><a href="http://www.unicode.org/versions/latest/"><cite>The Unicode Standard</cite></a>. URL: <a href="http://www.unicode.org/versions/latest/">http://www.unicode.org/versions/latest/</a>
-</dd><dt id="bib-XMLSCHEMA11-2">[XMLSCHEMA11-2]</dt><dd rel="dcterms:requires">David Peterson; Sandy Gao; Ashok Malhotra; Michael Sperberg-McQueen; Henry Thompson; Paul V. Biron et al. <a href="http://www.w3.org/TR/xmlschema11-2/"><cite>W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes</cite></a>. 5 April 2012. W3C Recommendation. URL: <a href="http://www.w3.org/TR/xmlschema11-2/">http://www.w3.org/TR/xmlschema11-2/</a>
-</dd></dl></section><section id="informative-references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h3 aria-level="2" role="heading" id="h3_informative-references"><span class="secno">C.2 </span>Informative references</h3><dl class="bibliography" about=""><dt id="bib-COOLURIS">[COOLURIS]</dt><dd rel="dcterms:references">Leo Sauermann; Richard Cyganiak. <a href="http://www.w3.org/TR/cooluris"><cite>Cool URIs for the Semantic Web</cite></a>. 3 December 2008. W3C Note. URL: <a href="http://www.w3.org/TR/cooluris">http://www.w3.org/TR/cooluris</a>
-</dd><dt id="bib-DOM4">[DOM4]</dt><dd rel="dcterms:references">Anne van Kesteren; Aryeh Gregor; Ms2ger; Alex Russell; Robin Berjon. <a href="http://www.w3.org/TR/dom/"><cite>W3C DOM4</cite></a>. 7 November 2013. W3C Working Draft. URL: <a href="http://www.w3.org/TR/dom/">http://www.w3.org/TR/dom/</a>
-</dd><dt id="bib-HTML-RDFA">[HTML-RDFA]</dt><dd rel="dcterms:references">Manu Sporny. <a href="http://www.w3.org/TR/html-rdfa/"><cite>HTML+RDFa 1.1</cite></a>. 22 August 2013. W3C Recommendation. URL: <a href="http://www.w3.org/TR/html-rdfa/">http://www.w3.org/TR/html-rdfa/</a>
-</dd><dt id="bib-HTML5">[HTML5]</dt><dd rel="dcterms:references">Robin Berjon; Steve Faulkner; Travis Leithead; Erika Doyle Navara; Edward O'Connor; Silvia Pfeiffer. <a href="http://www.w3.org/TR/html5/"><cite>HTML5</cite></a>. 6 August 2013. W3C Candidate Recommendation. URL: <a href="http://www.w3.org/TR/html5/">http://www.w3.org/TR/html5/</a>
-</dd><dt id="bib-JSON-LD">[JSON-LD]</dt><dd rel="dcterms:references">Manu Sporny, Gregg Kellogg, Markus Lanthaler, Editors. <cite><a href="http://www.w3.org/TR/json-ld/">JSON-LD 1.0</a></cite>. 16 January 2014. W3C Recommendation. URL: <a href="http://www.w3.org/TR/json-ld/">http://www.w3.org/TR/json-ld/</a>
-</dd><dt id="bib-LINKED-DATA">[LINKED-DATA]</dt><dd rel="dcterms:references">Tim Berners-Lee. <cite><a href="http://www.w3.org/DesignIssues/LinkedData.html">Linked Data</a></cite>. Personal View, imperfect but published. URL: <a href="http://www.w3.org/DesignIssues/LinkedData.html">http://www.w3.org/DesignIssues/LinkedData.html</a>
-</dd><dt id="bib-OWL2-OVERVIEW">[OWL2-OVERVIEW]</dt><dd rel="dcterms:references">W3C OWL Working Group. <a href="http://www.w3.org/TR/owl2-overview/"><cite>OWL 2 Web Ontology Language Document Overview (Second Edition)</cite></a>. 11 December 2012. W3C Recommendation. URL: <a href="http://www.w3.org/TR/owl2-overview/">http://www.w3.org/TR/owl2-overview/</a>
-</dd><dt id="bib-RDF11-DATASETS">[RDF11-DATASETS]</dt><dd rel="dcterms:references">Antoine Zimmermann. <cite><a href="http://www.w3.org/TR/2014/NOTE-rdf11-datasets-20140225/">RDF 1.1: On Semantics of Datasets</a></cite>. W3C Working Group Note, 25 February 2014. The latest version is available at <a href="http://www.w3.org/TR/rdf11-datasets/">http://www.w3.org/TR/rdf11-datasets/</a>.
-</dd><dt id="bib-RDF11-MT">[RDF11-MT]</dt><dd rel="dcterms:references">Patrick J. Hayes, Peter F. Patel-Schneider. <cite><a href="http://www.w3.org/TR/2014/REC-rdf11-mt-20140225/">RDF 1.1 Semantics.</a></cite> W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-rdf11-mt-20140225/">http://www.w3.org/TR/2014/REC-rdf11-mt-20140225/</a>. The latest edition is available at <a href="http://www.w3.org/TR/rdf11-mt/">http://www.w3.org/TR/rdf11-mt/</a>
-</dd><dt id="bib-RDF11-NEW">[RDF11-NEW]</dt><dd rel="dcterms:references">David Wood. <cite><a href="http://www.w3.org/TR/2014/NOTE-rdf11-new-20140225/">What’s New in RDF 1.1</a></cite>. W3C Working Group Note, 25 February 2014. The latest version is available at <a href="http://www.w3.org/TR/rdf11-new/">http://www.w3.org/TR/rdf11-new/</a>.
-</dd><dt id="bib-RDF11-PRIMER">[RDF11-PRIMER]</dt><dd rel="dcterms:references">Guus Schreiber, Yves Raimond. <cite><a href="http://www.w3.org/TR/2014/NOTE-rdf11-primer-20140225/">RDF 1.1 Primer</a></cite>. W3C Working Group Note, 25 February 2014. The latest version is available at <a href="http://www.w3.org/TR/rdf11-primer/">http://www.w3.org/TR/rdf11-primer/</a>.
-</dd><dt id="bib-RDF11-SCHEMA">[RDF11-SCHEMA]</dt><dd rel="dcterms:references">Dan Brickley, R. V. Guha. <cite><a href="http://www.w3.org/TR/2014/REC-rdf-schema-20140225/">RDF Schema 1.1</a></cite>. W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-rdf-schema-20140225/">http://www.w3.org/TR/2014/REC-rdf-schema-20140225/</a>. The latest published version is available at <a href="http://www.w3.org/TR/rdf-schema/">http://www.w3.org/TR/rdf-schema/</a>.
-</dd><dt id="bib-RDF11-TESTCASES">[RDF11-TESTCASES]</dt><dd rel="dcterms:references">Gregg Kellogg, Markus Lanthaler. <cite><a href="http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/">RDF 1.1 Test Cases</a></cite>. W3C Working Group Note, 25 February 2014. The latest published version is available at <a href="http://www.w3.org/TR/rdf11-testcases/">http://www.w3.org/TR/rdf11-testcases/</a>.
-</dd><dt id="bib-RDF11-XML">[RDF11-XML]</dt><dd rel="dcterms:references">Fabien Gandon, Guus Schreiber. <cite><a href="http://www.w3.org/TR/2014/REC-rdf-syntax-grammar-20140225/">RDF 1.1 XML Syntax</a></cite>. W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-rdf-syntax-grammar-20140225/">http://www.w3.org/TR/2014/REC-rdf-syntax-grammar-20140225/</a>. The latest published version is available at <a href="http://www.w3.org/TR/rdf-syntax-grammar/">http://www.w3.org/TR/rdf-syntax-grammar/</a>.
-</dd><dt id="bib-RDFA-PRIMER">[RDFA-PRIMER]</dt><dd rel="dcterms:references">Ivan Herman; Ben Adida; Manu Sporny; Mark Birbeck. <a href="http://www.w3.org/TR/rdfa-primer/"><cite>RDFa 1.1 Primer - Second Edition</cite></a>. 22 August 2013. W3C Note. URL: <a href="http://www.w3.org/TR/rdfa-primer/">http://www.w3.org/TR/rdfa-primer/</a>
-</dd><dt id="bib-RFC3986">[RFC3986]</dt><dd rel="dcterms:references">T. Berners-Lee; R. Fielding; L. Masinter. <a href="http://www.ietf.org/rfc/rfc3986.txt"><cite>Uniform Resource Identifier (URI): Generic Syntax (RFC 3986)</cite></a>. January 2005. RFC. URL: <a href="http://www.ietf.org/rfc/rfc3986.txt">http://www.ietf.org/rfc/rfc3986.txt</a>
-</dd><dt id="bib-RFC5785">[RFC5785]</dt><dd rel="dcterms:references">Mark Nottingham; Eran Hammer-Lahav. <a href="http://www.rfc-editor.org/rfc/rfc5785.txt"><cite>Defining Well-Known Uniform Resource Identifiers (URIs) (RFC 5785)</cite></a>. April 2010. RFC. URL: <a href="http://www.rfc-editor.org/rfc/rfc5785.txt">http://www.rfc-editor.org/rfc/rfc5785.txt</a>
-</dd><dt id="bib-SPARQL11-OVERVIEW">[SPARQL11-OVERVIEW]</dt><dd rel="dcterms:references">The W3C SPARQL Working Group. <a href="http://www.w3.org/TR/sparql11-overview/"><cite>SPARQL 1.1 Overview</cite></a>. 21 March 2013. W3C Recommendation. URL: <a href="http://www.w3.org/TR/sparql11-overview/">http://www.w3.org/TR/sparql11-overview/</a>
-</dd><dt id="bib-SWBP-N-ARYRELATIONS">[SWBP-N-ARYRELATIONS]</dt><dd rel="dcterms:references">Natasha Noy; Alan Rector. <a href="http://www.w3.org/TR/swbp-n-aryRelations"><cite>Defining N-ary Relations on the Semantic Web</cite></a>. 12 April 2006. W3C Note. URL: <a href="http://www.w3.org/TR/swbp-n-aryRelations">http://www.w3.org/TR/swbp-n-aryRelations</a>
-</dd><dt id="bib-SWBP-XSCH-DATATYPES">[SWBP-XSCH-DATATYPES]</dt><dd rel="dcterms:references">Jeremy Carroll; Jeff Pan. <a href="http://www.w3.org/TR/swbp-xsch-datatypes"><cite>XML Schema Datatypes in RDF and OWL</cite></a>. 14 March 2006. W3C Note. URL: <a href="http://www.w3.org/TR/swbp-xsch-datatypes">http://www.w3.org/TR/swbp-xsch-datatypes</a>
-</dd><dt id="bib-TRIG">[TRIG]</dt><dd rel="dcterms:references">Gavin Carothers, Andy Seaborne. <cite><a href="http://www.w3.org/TR/2014/REC-trig-20140225/">TriG: RDF Dataset Language</a></cite>. W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-trig-20140225/">http://www.w3.org/TR/2014/REC-trig-20140225/</a>. The latest edition is available at <a href="http://www.w3.org/TR/trig/">http://www.w3.org/TR/trig/</a>
-</dd><dt id="bib-TURTLE">[TURTLE]</dt><dd rel="dcterms:references">Eric Prud'hommeaux, Gavin Carothers. <cite><a href="http://www.w3.org/TR/2014/REC-turtle-20140225/">RDF 1.1 Turtle: Terse RDF Triple Language.</a></cite> W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-turtle-20140225/">http://www.w3.org/TR/2014/REC-turtle-20140225/</a>. The latest edition is available at <a href="http://www.w3.org/TR/turtle/">http://www.w3.org/TR/turtle/</a>
-</dd><dt id="bib-VOCAB-ORG">[VOCAB-ORG]</dt><dd rel="dcterms:references">Dave Reynolds. <a href="http://www.w3.org/TR/vocab-org/"><cite>The Organization Ontology</cite></a>. 16 January 2014. W3C Recommendation. URL: <a href="http://www.w3.org/TR/vocab-org/">http://www.w3.org/TR/vocab-org/</a>
-</dd><dt id="bib-WEBARCH">[WEBARCH]</dt><dd rel="dcterms:references">Ian Jacobs; Norman Walsh. <a href="http://www.w3.org/TR/webarch/"><cite>Architecture of the World Wide Web, Volume One</cite></a>. 15 December 2004. W3C Recommendation. URL: <a href="http://www.w3.org/TR/webarch/">http://www.w3.org/TR/webarch/</a>
-</dd><dt id="bib-XML-EXC-C14N">[XML-EXC-C14N]</dt><dd rel="dcterms:references">John Boyer; Donald Eastlake; Joseph Reagle. <a href="http://www.w3.org/TR/xml-exc-c14n"><cite>Exclusive XML Canonicalization Version 1.0</cite></a>. 18 July 2002. W3C Recommendation. URL: <a href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a>
-</dd><dt id="bib-XML-NAMES">[XML-NAMES]</dt><dd rel="dcterms:references">Tim Bray; Dave Hollander; Andrew Layman; Richard Tobin; Henry Thompson et al. <a href="http://www.w3.org/TR/xml-names"><cite>Namespaces in XML 1.0 (Third Edition)</cite></a>. 8 December 2009. W3C Recommendation. URL: <a href="http://www.w3.org/TR/xml-names">http://www.w3.org/TR/xml-names</a>
-</dd><dt id="bib-XML10">[XML10]</dt><dd rel="dcterms:references">Tim Bray; Jean Paoli; Michael Sperberg-McQueen; Eve Maler; François Yergeau et al. <a href="http://www.w3.org/TR/xml"><cite>Extensible Markup Language (XML) 1.0 (Fifth Edition)</cite></a>. 26 November 2008. W3C Recommendation. URL: <a href="http://www.w3.org/TR/xml">http://www.w3.org/TR/xml</a>
-</dd></dl></section></section></body></html>
\ No newline at end of file
+<!DOCTYPE html>
+<html lang="en" typeof="bibo:Document w3p:REC" about="" property="dcterms:language" content="en" prefix="bibo: http://purl.org/ontology/bibo/ w3p: http://www.w3.org/2001/02pd/rec54#" xmlns="http://www.w3.org/1999/xhtml">
+<head>
+  <meta charset="utf-8">
+  <title>RDF 1.1 Concepts and Abstract Syntax</title>
+  <style type="text/css">
+    figure { text-align: center; }
+    table td, table th { border: 1px solid #ddd; padding: 0.2em 0.5em; }
+    ol ol { list-style-type: lower-latin; }
+  </style>
+  <style>
+    /* --- 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:  #ff4500;
+    }
+    /* --- 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>/* --- ISSUES/NOTES --- */
+    div.issue-title, div.note-title {
+        padding-right:  1em;
+        min-width: 7.5em;
+        color: #b9ab2d;
+    }
+    div.issue-title { color: #e05252; }
+    div.note-title { color: #2b2; }
+    div.issue-title span, div.note-title span {
+        text-transform: uppercase;
+    }
+    div.note, div.issue {
+        margin-top: 1em;
+        margin-bottom: 1em;
+    }
+    .note > p:first-child, .issue > p:first-child { margin-top: 0 }
+    .issue, .note {
+        padding: .5em;
+        border-left-width: .5em;
+        border-left-style: solid;
+    }
+    div.issue, div.note {
+        padding: 1em 1.2em 0.5em;
+        margin: 1em 0;
+        position: relative;
+        clear: both;
+    }
+    span.note, span.issue { padding: .1em .5em .15em; }
+    .issue {
+        border-color: #e05252;
+        background: #fbe9e9;
+    }
+    .note {
+        border-color: #52e052;
+        background: #e9fbe9;
+    }
+  </style>
+  <link rel="stylesheet" href="https://www.w3.org/StyleSheets/TR/W3C-REC">
+  <!--[if lt IE 9]><script src='https://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]-->
+</head>
+<body class="h-entry" style="" role="document" id="respecDocument"><div class="head" role="contentinfo" id="respecHeader">
+  <p><a 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">RDF 1.1 Concepts and Abstract Syntax</h1>
+  <h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-02-24T23:00:00.000Z" id="w3c-recommendation-25-february-2014"><abbr title="World Wide Web Consortium">W3C</abbr> Recommendation <time class="dt-published" datetime="2014-02-25">25 February 2014</time></h2>
+  <dl>
+      <dt>This version:</dt>
+      <dd><a class="u-url" href="http://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/">http://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/</a></dd>
+      <dt>Latest published version:</dt>
+      <dd><a href="http://www.w3.org/TR/rdf11-concepts/">http://www.w3.org/TR/rdf11-concepts/</a></dd>
+      <dt>Implementation report:</dt>
+      <dd><a href="http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/">http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/</a></dd>
+      <dt>Previous version:</dt>
+      <dd><a rel="dcterms:replaces" href="http://www.w3.org/TR/2014/PR-rdf11-concepts-20140109/">http://www.w3.org/TR/2014/PR-rdf11-concepts-20140109/</a></dd>
+          <dt>Previous Recommendation:</dt>
+          <dd><a rel="dcterms:replaces" href="http://www.w3.org/TR/rdf-concepts">http://www.w3.org/TR/rdf-concepts</a></dd>
+    <dt>Editors:</dt>
+    <dd class="p-author h-card vcard" rel="bibo:editor" inlist=""><span typeof="foaf:Person"><a class="u-url url p-name fn" rel="foaf:homepage" property="foaf:name" content="Richard Cyganiak" href="http://richard.cyganiak.de/">Richard Cyganiak</a>, <a rel="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.deri.ie/">DERI, NUI Galway</a></span>
+</dd>
+<dd class="p-author h-card vcard" rel="bibo:editor" inlist=""><span typeof="foaf:Person"><a class="u-url url p-name fn" rel="foaf:homepage" property="foaf:name" content="David Wood" href="http://about.me/david_wood">David Wood</a>, <a rel="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://3roundstones.com/">3 Round Stones</a></span>
+</dd>
+<dd class="p-author h-card vcard" rel="bibo:editor" inlist=""><span typeof="foaf:Person"><a class="u-url url p-name fn" rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">Markus Lanthaler</a>, <a rel="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.tugraz.at/">Graz University of Technology</a></span>
+</dd>
+          <dt>Previous Editors:</dt>
+                  <dd>
+                      Graham Klyne
+                  </dd>
+                  <dd>
+                      Jeremy J. Carroll
+                  </dd>
+                  <dd>
+                      Brian McBride
+                  </dd>
+  </dl>
+    <p>
+      Please check the <a href="http://www.w3.org/2014/rdf1.1-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-20140109.html">diff to previous version</a>
+    </p>
+    <p>
+      The English version of this specification is the only normative version. Non-normative
+      <a href="http://www.w3.org/Consortium/Translation/">translations</a> may also be available.
+    </p>
+      <p class="copyright">
+        <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> ©
+        2004-2014
+        <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>),
+        All Rights Reserved.
+        <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 href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a>
+        rules apply.
+      </p>
+  <hr>
+</div>
+  <section id="abstract" class="introductory" property="dcterms:abstract" datatype="" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h2 aria-level="1" role="heading" id="h2_abstract">Abstract</h2>
+      <p>The Resource Description Framework (RDF) is a framework for
+      representing information in the Web. This document defines an abstract syntax
+      (a data model) which serves to link all RDF-based languages and
+      specifications. The abstract syntax has two key data structures:
+      RDF graphs are sets of subject-predicate-object triples,
+      where the elements may be IRIs, blank nodes, or datatyped literals. They
+      are used to express descriptions of resources. RDF datasets are used
+      to organize collections of RDF graphs, and comprise a default graph
+      and zero or more named graphs. RDF&nbsp;1.1 Concepts and Abstract Syntax
+      also introduces key concepts and terminology, and discusses
+      datatyping and the handling of fragment identifiers in IRIs within
+      RDF graphs.</p>
+  </section><section id="sotd" class="introductory" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h2 aria-level="1" role="heading" id="h2_sotd">Status of This Document</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>This document is part of the RDF 1.1 document suite. It is the central
+    RDF 1.1 specification and defines the core RDF concepts. A new concept in
+    RDF 1.1 is the notion of an RDF dataset to represent multiple graphs.
+    There have been no changes to this document since its publication as
+    Proposed Recommendation.</p>
+        <p>
+          This document was published by the <a href="http://www.w3.org/2011/rdf-wg/">RDF Working Group</a> as a Recommendation.
+            If you wish to make comments regarding this document, please send them to
+            <a href="mailto:[email protected]">[email protected]</a>
+            (<a href="mailto:[email protected]?subject=subscribe">subscribe</a>,
+            <a href="http://lists.w3.org/Archives/Public/public-rdf-comments/">archives</a>).
+            All comments are welcome.
+        </p>
+          <p>
+            Please see the Working Group's  <a href="http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/">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" about="" rel="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/46168/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>
+</section><section id="toc"><h2 class="introductory" aria-level="1" role="heading" id="h2_toc">Table of Contents</h2><ul class="toc" role="directory" id="respecContents"><li class="tocline"><a href="#section-Introduction" class="tocxref"><span class="secno">1. </span>Introduction</a><ul class="toc"><li class="tocline"><a href="#data-model" class="tocxref"><span class="secno">1.1 </span>Graph-based Data Model</a></li><li class="tocline"><a href="#resources-and-statements" class="tocxref"><span class="secno">1.2 </span>Resources and Statements</a></li><li class="tocline"><a href="#referents" class="tocxref"><span class="secno">1.3 </span>The Referent of an <abbr title="Internationalized Resource Identifier">IRI</abbr></a></li><li class="tocline"><a href="#vocabularies" class="tocxref"><span class="secno">1.4 </span>RDF Vocabularies and Namespace IRIs</a></li><li class="tocline"><a href="#change-over-time" class="tocxref"><span class="secno">1.5 </span>RDF and Change over Time</a></li><li class="tocline"><a href="#managing-graphs" class="tocxref"><span class="secno">1.6 </span>Working with Multiple RDF Graphs</a></li><li class="tocline"><a href="#entailment" class="tocxref"><span class="secno">1.7 </span>Equivalence, Entailment and Inconsistency</a></li><li class="tocline"><a href="#rdf-documents" class="tocxref"><span class="secno">1.8 </span>RDF Documents and Syntaxes</a></li></ul></li><li class="tocline"><a href="#conformance" class="tocxref"><span class="secno">2. </span>Conformance</a></li><li class="tocline"><a href="#section-rdf-graph" class="tocxref"><span class="secno">3. </span>RDF Graphs</a><ul class="toc"><li class="tocline"><a href="#section-triples" class="tocxref"><span class="secno">3.1 </span>Triples</a></li><li class="tocline"><a href="#section-IRIs" class="tocxref"><span class="secno">3.2 </span>IRIs</a></li><li class="tocline"><a href="#section-Graph-Literal" class="tocxref"><span class="secno">3.3 </span>Literals</a></li><li class="tocline"><a href="#section-blank-nodes" class="tocxref"><span class="secno">3.4 </span>Blank Nodes</a></li><li class="tocline"><a href="#section-skolemization" class="tocxref"><span class="secno">3.5 </span>Replacing Blank Nodes with IRIs</a></li><li class="tocline"><a href="#graph-isomorphism" class="tocxref"><span class="secno">3.6 </span>Graph Comparison</a></li></ul></li><li class="tocline"><a href="#section-dataset" class="tocxref"><span class="secno">4. </span>RDF Datasets</a><ul class="toc"><li class="tocline"><a href="#section-dataset-isomorphism" class="tocxref"><span class="secno">4.1 </span>RDF Dataset Comparison</a></li><li class="tocline"><a href="#section-dataset-conneg" class="tocxref"><span class="secno">4.2 </span>Content Negotiation of RDF Datasets</a></li></ul></li><li class="tocline"><a href="#section-Datatypes" class="tocxref"><span class="secno">5. </span>Datatypes</a><ul class="toc"><li class="tocline"><a href="#xsd-datatypes" class="tocxref"><span class="secno">5.1 </span>The XML Schema Built-in Datatypes</a></li><li class="tocline"><a href="#section-html" class="tocxref"><span class="secno">5.2 </span>The <code>rdf:HTML</code> Datatype</a></li><li class="tocline"><a href="#section-XMLLiteral" class="tocxref"><span class="secno">5.3 </span>The <code>rdf:XMLLiteral</code> Datatype</a></li><li class="tocline"><a href="#datatype-iris" class="tocxref"><span class="secno">5.4 </span>Datatype IRIs</a></li></ul></li><li class="tocline"><a href="#section-fragID" class="tocxref"><span class="secno">6. </span>Fragment Identifiers</a></li><li class="tocline"><a href="#section-generalized-rdf" class="tocxref"><span class="secno">7. </span>Generalized RDF Triples, Graphs, and Datasets</a></li><li class="tocline"><a href="#section-Acknowledgments" class="tocxref"><span class="secno">8. </span>Acknowledgments</a></li><li class="tocline"><a href="#changes" class="tocxref"><span class="secno">A. </span>Changes between RDF 1.0 and RDF 1.1</a></li><li class="tocline"><a href="#references" class="tocxref"><span class="secno">B. </span>References</a><ul class="toc"><li class="tocline"><a href="#normative-references" class="tocxref"><span class="secno">B.1 </span>Normative references</a></li><li class="tocline"><a href="#informative-references" class="tocxref"><span class="secno">B.2 </span>Informative references</a></li></ul></li></ul></section>
+
+<section id="section-Introduction" class="informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <!--OddPage--><h2 aria-level="1" role="heading" id="h2_section-Introduction"><span class="secno">1. </span>Introduction</h2><p><em>This section is non-normative.</em></p>
+
+    <p>The <em>Resource Description Framework</em> (RDF) is a framework
+    for representing information in the Web.</p>
+
+    <p>This document defines an abstract syntax (a data model)
+    which serves to link all RDF-based languages and specifications,
+    including:</p>
+
+    <ul>
+      <li>the <a href="http://www.w3.org/TR/rdf11-mt/">formal
+        model-theoretic semantics for RDF and RDFS</a> [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>]</li>
+
+      <li>serialization syntaxes for storing and exchanging RDF such as
+        <a href="http://www.w3.org/TR/turtle/">Turtle</a> [<cite><a class="bibref" href="#bib-TURTLE">TURTLE</a></cite>]
+        and <a href="http://www.w3.org/TR/json-ld/">JSON-LD</a> [<cite><a class="bibref" href="#bib-JSON-LD">JSON-LD</a></cite>]</li>
+
+      <li>the <a href="http://www.w3.org/TR/rdf-sparql-query/">SPARQL
+        Query Language</a> [<cite><a class="bibref" href="#bib-SPARQL11-OVERVIEW">SPARQL11-OVERVIEW</a></cite>]</li>
+
+      <li>the <a href="http://www.w3.org/TR/rdf-schema/">RDF Vocabulary
+        Description Language</a> (RDFS) [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>]</li>
+    </ul>
+
+<section id="data-model" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_data-model"><span class="secno">1.1 </span>Graph-based Data Model</h3>
+
+    <p>The core structure of the abstract syntax is a set of
+    <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">triples</a>, each consisting of a <a href="#dfn-subject" class="internalDFN">subject</a>,
+    a <a href="#dfn-predicate" class="internalDFN">predicate</a> and an <a href="#dfn-object" class="internalDFN">object</a>. A set of such triples is called
+    an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>. An RDF graph can be visualized as a node and
+    directed-arc diagram, in which each triple is represented as a
+    node-arc-node link.</p>
+
+    <figure id="fig-an-rdf-graph-with-two-nodes-subject-and-object-and-a-triple-connecting-them-predicate">
+      <a href="rdf-graph.svg"><img src="rdf-graph.svg" alt="An RDF graph with two nodes (Subject and Object) and a triple connecting them (Predicate)"></a>
+      <figcaption>Fig. <span class="figno">1</span> <span class="fig-title">An RDF graph with two nodes (Subject and Object) and a triple connecting them (Predicate)</span></figcaption>
+    </figure>
+
+    <p>There can be three kinds of <a title="node" href="#dfn-node" class="internalDFN">nodes</a> in an
+    <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>: <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>, <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>,
+    and <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a>.</p>
+</section>
+
+
+<section id="resources-and-statements" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_resources-and-statements"><span class="secno">1.2 </span>Resources and Statements</h3>
+
+    <p>Any <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or <a href="#dfn-literal" class="internalDFN">literal</a> <dfn title="denote" id="dfn-denote">denotes</dfn>
+    something in the world (the "universe of discourse").
+    These things are called
+    <dfn title="resource" id="dfn-resource">resources</dfn>. Anything can be a resource,
+    including physical things, documents, abstract concepts, numbers
+    and strings; the term is synonymous with "entity" as it is used in
+    the RDF Semantics specification [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>].
+    The resource denoted by an <abbr title="Internationalized Resource Identifier">IRI</abbr> is called its <a href="#dfn-referent" class="internalDFN">referent</a>, and the
+    resource denoted by a literal is called its
+    <a title="literal value" href="#dfn-literal-value" class="internalDFN">literal value</a>. Literals have
+    <a title="datatype" href="#dfn-datatype" class="internalDFN">datatypes</a> that define the range of possible
+    values, such as strings, numbers, and dates. Special kind of literals,
+    <a title="language-tagged string" href="#dfn-language-tagged-string" class="internalDFN">language-tagged strings</a>, denote
+    plain-text strings in a natural language.</p>
+
+    <p>Asserting an <a href="#dfn-rdf-triple" class="internalDFN">RDF triple</a> says that <em>some relationship,
+    indicated by the <a href="#dfn-predicate" class="internalDFN">predicate</a>, holds between the
+    <a title="resource" href="#dfn-resource" class="internalDFN">resources</a> <a title="denote" href="#dfn-denote" class="internalDFN">denoted</a> by
+    the <a href="#dfn-subject" class="internalDFN">subject</a> and <a href="#dfn-object" class="internalDFN">object</a></em>. This statement corresponding
+    to an RDF triple is known as an <dfn id="dfn-rdf-statement">RDF statement</dfn>.
+    The predicate itself is an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> and denotes a <dfn id="dfn-property">property</dfn>,
+    that is, a <a href="#dfn-resource" class="internalDFN">resource</a> that can be thought of as a binary relation.
+    (Relations that involve more than two entities can only be
+    <a href="http://www.w3.org/TR/swbp-n-aryRelations/">indirectly
+    expressed in RDF</a> [<cite><a class="bibref" href="#bib-SWBP-N-ARYRELATIONS">SWBP-N-ARYRELATIONS</a></cite>].)</p>
+
+    <p>Unlike <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> and <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>,
+      <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a> do not identify specific
+      <a title="resource" href="#dfn-resource" class="internalDFN">resources</a>. <a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">Statements</a>
+      involving blank nodes say that something with the given relationships
+      exists, without explicitly naming it.</p>
+</section>
+
+
+<section id="referents" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_referents"><span class="secno">1.3 </span>The Referent of an <abbr title="Internationalized Resource Identifier">IRI</abbr></h3>
+
+    <p>The <a href="#dfn-resource" class="internalDFN">resource</a> <a title="denote" href="#dfn-denote" class="internalDFN">denoted</a> by an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+      is also called its <dfn id="dfn-referent">referent</dfn>. For some IRIs with particular
+      meanings, such as those identifying XSD datatypes, the referent is
+      fixed by this specification. For all other IRIs, what exactly is
+      denoted by any given <abbr title="Internationalized Resource Identifier">IRI</abbr> is not defined by this specification. Other
+      specifications may fix <abbr title="Internationalized Resource Identifier">IRI</abbr> referents, or apply other constraints on
+      what may be the referent of any <abbr title="Internationalized Resource Identifier">IRI</abbr>.</p>
+
+    <p>Guidelines for determining the <a href="#dfn-referent" class="internalDFN">referent</a> of an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> are
+    provided in other documents, like
+    <em><a href="http://www.w3.org/TR/webarch/">Architecture of the World Wide Web, Volume One</a></em> [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>]
+    and <em><a href="http://www.w3.org/TR/cooluris/">Cool URIs for the Semantic Web</a></em> [<cite><a class="bibref" href="#bib-COOLURIS">COOLURIS</a></cite>].
+    A very brief, informal, and partial account follows:</p>
+
+    <ul>
+      <li>By design, IRIs have global scope. Thus, two different appearances of an <abbr title="Internationalized Resource Identifier">IRI</abbr>
+        <a href="#dfn-denote" class="internalDFN">denote</a> the same <a href="#dfn-resource" class="internalDFN">resource</a>. Violating this principle constitutes
+        an <a href="http://www.w3.org/TR/webarch/#URI-collision"><abbr title="Internationalized Resource Identifier">IRI</abbr> collision</a> [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>].</li>
+
+      <li>By social convention, the
+        <a href="http://www.w3.org/TR/webarch/#uri-ownership"><abbr title="Internationalized Resource Identifier">IRI</abbr> owner</a>
+        [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>] gets to say what the intended (or usual)
+        referent of an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> is.  Applications and users need not
+        abide by this intended denotation, but there may be a loss of
+        interoperability with other applications and users if they do
+        not do so.</li>
+
+      <li>The <abbr title="Internationalized Resource Identifier">IRI</abbr> owner can establish the intended <a href="#dfn-referent" class="internalDFN">referent</a>
+        by means of a specification or other document that explains
+        what is denoted. For example, the
+        <a href="http://www.w3.org/TR/vocab-org/">Organization Ontology document</a> [<cite><a class="bibref" href="#bib-VOCAB-ORG">VOCAB-ORG</a></cite>]
+        specifies the intended referents of various IRIs that start with
+        <code>http://www.w3.org/ns/org#</code>.</li>
+
+      <li>A good way of communicating the intended referent
+        is to set up the <abbr title="Internationalized Resource Identifier">IRI</abbr> so that it
+        <a href="http://www.w3.org/TR/webarch/#uri-dereference">dereferences</a> [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>]
+        to such a document.</li>
+
+      <li>Such a document can, in fact, be an <a href="#dfn-rdf-document" class="internalDFN">RDF document</a>
+        that describes the denoted resource by means of
+        <a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">RDF statements</a>.</li>
+    </ul>
+
+    <p>Perhaps the most important characteristic of <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>
+      in web architecture is that they can be
+      <a href="http://www.w3.org/TR/webarch/#uri-dereference">dereferenced</a>,
+      and hence serve as starting points for interactions with a remote server.
+      This specification is not concerned with such interactions.
+      It does not define an interaction model. It only treats IRIs as globally
+      unique identifiers in a graph data model that describes resources.
+      However, those interactions are critical to the concept of
+      <em><a href="http://www.w3.org/DesignIssues/LinkedData.html">Linked Data</a></em> [<cite><a class="bibref" href="#bib-LINKED-DATA">LINKED-DATA</a></cite>],
+      which makes use of the RDF data model and serialization formats.</p>
+</section>
+
+<section id="vocabularies" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_vocabularies"><span class="secno">1.4 </span>RDF Vocabularies and Namespace IRIs</h3>
+
+    <p>An <dfn id="dfn-rdf-vocabulary">RDF vocabulary</dfn> is a collection of <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>
+      intended for use in <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>. For example,
+      the IRIs documented in [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>] are the RDF Schema vocabulary.
+      RDF Schema can itself be used to define and document additional
+      RDF vocabularies. Some such vocabularies are mentioned in the
+      Primer [<cite><a class="bibref" href="#bib-RDF11-PRIMER">RDF11-PRIMER</a></cite>].</p>
+
+    <p>The <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> in an <a href="#dfn-rdf-vocabulary" class="internalDFN">RDF vocabulary</a> often begin with
+      a common substring known as a <dfn id="dfn-namespace-iri">namespace <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>.
+      Some namespace IRIs are associated by convention with a short name
+      known as a <dfn id="dfn-namespace-prefix">namespace prefix</dfn>. Some examples:
+
+    </p><table class="simple">
+      <caption>Some example namespace prefixes and IRIs</caption>
+      <tbody><tr>
+        <th>Namespace prefix</th>
+        <th>Namespace <abbr title="Internationalized Resource Identifier">IRI</abbr></th>
+        <th>RDF vocabulary</th>
+      </tr>
+      <tr>
+        <td>rdf</td>
+        <td><a href="http://www.w3.org/1999/02/22-rdf-syntax-ns#"><code>http://www.w3.org/1999/02/22-rdf-syntax-ns#</code></a></td>
+        <td>The RDF built-in vocabulary [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>]</td>
+      </tr>
+      <tr><td>rdfs</td>
+        <td><a href="http://www.w3.org/2000/01/rdf-schema#"><code>http://www.w3.org/2000/01/rdf-schema#</code></a></td>
+        <td>The RDF Schema vocabulary [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>]</td>
+      </tr>
+      <tr><td>xsd</td>
+        <td><a href="http://www.w3.org/2001/XMLSchema#"><code>http://www.w3.org/2001/XMLSchema#</code></a></td>
+        <td>The <a href="#dfn-rdf-compatible-xsd-types" class="internalDFN">RDF-compatible XSD types</a></td>
+      </tr>
+    </tbody></table>
+
+    <p>In some serialization formats it is common to abbreviate <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>
+      that start with <a title="namespace IRI" href="#dfn-namespace-iri" class="internalDFN">namespace IRIs</a> by using a
+      <a href="#dfn-namespace-prefix" class="internalDFN">namespace prefix</a> in order to assist readability. For example, the <abbr title="Internationalized Resource Identifier">IRI</abbr>
+      <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>
+      would be abbreviated as <code>rdf:XMLLiteral</code>.
+      Note however that these abbreviations are <em>not</em> valid IRIs,
+      and must not be used in contexts where IRIs are expected.
+      Namespace IRIs and namespace prefixes are <em>not</em> a formal part of the
+      RDF data model. They are merely a syntactic convenience for
+      abbreviating IRIs.</p>
+
+    <p>The term “<dfn id="dfn-namespace">namespace</dfn>” on its own does not have a
+      well-defined meaning in the context of RDF, but is sometimes informally
+      used to mean “<a href="#dfn-namespace-iri" class="internalDFN">namespace <abbr title="Internationalized Resource Identifier">IRI</abbr></a>” or “<a href="#dfn-rdf-vocabulary" class="internalDFN">RDF vocabulary</a>”.</p>
+</section>
+
+
+<section id="change-over-time" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_change-over-time"><span class="secno">1.5 </span>RDF and Change over Time</h3>
+
+    <p>The RDF data model is <em>atemporal</em>: <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>
+      are static snapshots of information.</p>
+
+    <p>However, <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a> can express information
+      about events and about temporal aspects of other entities,
+      given appropriate <a title="RDF vocabulary" href="#dfn-rdf-vocabulary" class="internalDFN">vocabulary</a> terms.</p>
+
+    <p>Since <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a> are defined as mathematical
+      sets, adding or removing <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">triples</a> from an
+      RDF graph yields a different RDF graph.</p>
+
+    <p>We informally use the term <dfn id="dfn-rdf-source">RDF source</dfn> to refer to a
+      persistent yet mutable source or container of
+      <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>. An RDF source is a <a href="#dfn-resource" class="internalDFN">resource</a>
+      that may be said to have a state that can change over time.
+      A snapshot of the state can be expressed as an RDF graph.
+      For example, any web document that has an RDF-bearing representation
+      may be considered an RDF source. Like all resources, RDF sources may
+      be named with <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> and therefore described in
+      other RDF graphs.</p>
+
+    <p>Intuitively speaking, changes in the universe of discourse
+      can be reflected in the following ways:</p>
+
+    <ul>
+      <li>An <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>, once minted, should never
+        change its intended <a href="#dfn-referent" class="internalDFN">referent</a>. (See
+        <a href="http://www.w3.org/TR/webarch/#URI-persistence"><abbr title="Uniform Resource Identifier">URI</abbr> persistence</a>
+        [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>].)</li>
+      <li><a title="literal" href="#dfn-literal" class="internalDFN">Literals</a>, by design, are constants and
+        never change their <a title="literal value" href="#dfn-literal-value" class="internalDFN">value</a>.</li>
+      <li>A relationship that holds between two <a title="resource" href="#dfn-resource" class="internalDFN">resources</a>
+        at one time may not hold at another time.</li>
+      <li><a title="RDF source" href="#dfn-rdf-source" class="internalDFN">RDF sources</a> may change their state over time.
+        That is, they may provide different <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>
+        at different times.</li>
+      <li>Some <a title="RDF source" href="#dfn-rdf-source" class="internalDFN">RDF sources</a> may, however, be immutable
+        snapshots of another RDF source, archiving its state at some
+        point in time.</li>
+    </ul>
+
+</section>
+
+
+<section id="managing-graphs" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_managing-graphs"><span class="secno">1.6 </span>Working with Multiple RDF Graphs</h3>
+
+    <p>As RDF graphs are sets of triples, they can be
+    combined easily, supporting the use of data from
+    multiple sources. Nevertheless, it is sometimes desirable to work
+    with multiple RDF graphs while keeping their contents separate.
+    <a title="RDF dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF datasets</a> support this requirement.</p>
+
+    <p>An <a href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a> is a collection of
+    <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>. All but one of these graphs have
+    an associated <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or blank node. They are called
+    <a title="named graph" href="#dfn-named-graph" class="internalDFN">named graphs</a>, and the <abbr title="Internationalized Resource Identifier">IRI</abbr> or blank node
+    is called the <a href="#dfn-graph-name" class="internalDFN">graph name</a>.
+    The remaining graph does not have an associated <abbr title="Internationalized Resource Identifier">IRI</abbr>, and is called
+    the <a href="#dfn-default-graph" class="internalDFN">default graph</a> of the RDF dataset.</p>
+
+    <p>There are many possible uses for <a title="RDF dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF datasets</a>.
+    One such use is to hold snapshots of multiple
+    <a title="RDF source" href="#dfn-rdf-source" class="internalDFN">RDF sources</a>.</p>
+</section>
+
+
+<section id="entailment" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_entailment"><span class="secno">1.7 </span>Equivalence, Entailment and Inconsistency</h3>
+
+    <p>An <a href="#dfn-rdf-triple" class="internalDFN">RDF triple</a> encodes a <a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">statement</a>—a
+    simple <dfn id="dfn-logical-expression">logical expression</dfn>, or claim about the world.
+    An <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> is the conjunction (logical <em>AND</em>) of
+    its triples.   The precise details of this meaning of RDF triples and graphs are
+    the subject of the RDF Semantics specification [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>], which yields the
+    following relationships between <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>s:</p>
+
+    <dl>
+    <dt><dfn id="dfn-entailment">Entailment</dfn></dt>
+    <dd>An <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> <em>A</em> entails another RDF graph <em>B</em>
+    if every possible arrangement of the world
+    that makes <em>A</em> true also makes <em>B</em> true. When <em>A</em>
+    entails <em>B</em>, if the truth of <em>A</em> is presumed or demonstrated
+    then the truth of <em>B</em> is established.</dd>
+
+    <dt><dfn id="dfn-equivalence">Equivalence</dfn></dt>
+    <dd>Two <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a> <em>A</em> and <em>B</em>
+    are equivalent if they make the same claim about the world.
+    <em>A</em> is equivalent to <em>B</em> if and only if
+    <em>A</em> <a title="entailment" href="#dfn-entailment" class="internalDFN">entails</a> <em>B</em> and
+    <em>B</em> entails <em>A</em>.</dd>
+
+    <dt><dfn id="dfn-inconsistency">Inconsistency</dfn></dt>
+    <dd>An <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> is inconsistent if it contains
+    an internal contradiction. There is no possible arrangement
+    of the world that would make the expression true.</dd>
+    </dl>
+
+    <p>An <dfn id="dfn-entailment-regime">entailment regime</dfn> [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>] is a specification that
+    defines precise conditions that make these relationships hold.
+    RDF itself recognizes only some basic cases of entailment, equivalence
+    and inconsistency. Other specifications, such as
+    <a href="http://www.w3.org/TR/rdf-schema/">RDF Schema</a> [<cite><a class="bibref" href="#bib-RDF11-SCHEMA">RDF11-SCHEMA</a></cite>]
+    and <a href="http://www.w3.org/TR/owl2-overview/">OWL 2</a>
+    [<cite><a class="bibref" href="#bib-OWL2-OVERVIEW">OWL2-OVERVIEW</a></cite>], add more powerful entailment regimes,
+    as do some domain-specific <a title="RDF vocabulary" href="#dfn-rdf-vocabulary" class="internalDFN">vocabularies</a>.
+    </p>
+
+    <p>This specification does not constrain how implementations
+    use the logical relationships defined by
+    <a title="entailment regime" href="#dfn-entailment-regime" class="internalDFN">entailment regimes</a>.
+    Implementations may or may not detect
+    <a title="inconsistency" href="#dfn-inconsistency" class="internalDFN">inconsistencies</a>, and may make all,
+    some or no <a title="entailment" href="#dfn-entailment" class="internalDFN">entailed</a> information
+    available to users.</p>
+</section>
+
+
+<section id="rdf-documents" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_rdf-documents"><span class="secno">1.8 </span>RDF Documents and Syntaxes</h3>
+
+    <p>An <dfn id="dfn-rdf-document">RDF document</dfn> is a document that encodes an
+    <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> or <a href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a> in a <dfn id="dfn-concrete-rdf-syntax">concrete RDF syntax</dfn>,
+    such as Turtle [<cite><a class="bibref" href="#bib-TURTLE">TURTLE</a></cite>], RDFa [<cite><a class="bibref" href="#bib-RDFA-PRIMER">RDFA-PRIMER</a></cite>], JSON-LD [<cite><a class="bibref" href="#bib-JSON-LD">JSON-LD</a></cite>], or
+    TriG [<cite><a class="bibref" href="#bib-TRIG">TRIG</a></cite>]. RDF documents enable the exchange of RDF graphs and RDF
+    datasets between systems.</p>
+
+    <p>A <a href="#dfn-concrete-rdf-syntax" class="internalDFN">concrete RDF syntax</a> may offer
+    many different ways to encode the same <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> or
+    <a href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a>, for example through the use of
+    <a title="namespace prefix" href="#dfn-namespace-prefix" class="internalDFN">namespace prefixes</a>,
+    relative IRIs, <a title="blank node identifier" href="#dfn-blank-node-identifier" class="internalDFN">blank node identifiers</a>,
+    and different ordering of statements. While these aspects can have great
+    effect on the convenience of working with the <a href="#dfn-rdf-document" class="internalDFN">RDF document</a>,
+    they are not significant for its meaning.</p>
+</section>
+
+
+</section>
+
+
+<section id="conformance" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><!--OddPage--><h2 aria-level="1" role="heading" id="h2_conformance"><span class="secno">2. </span>Conformance</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>
+  The key words <em class="rfc2119" title="MUST">MUST</em>, <em class="rfc2119" title="MUST NOT">MUST NOT</em>, <em class="rfc2119" title="REQUIRED">REQUIRED</em>, <em class="rfc2119" title="SHOULD">SHOULD</em>, <em class="rfc2119" title="SHOULD NOT">SHOULD NOT</em>, <em class="rfc2119" title="RECOMMENDED">RECOMMENDED</em>, <em class="rfc2119" title="MAY">MAY</em>,
+  and <em class="rfc2119" title="OPTIONAL">OPTIONAL</em> in this specification are to be interpreted as described in [<cite><a class="bibref" href="#bib-RFC2119">RFC2119</a></cite>].
+</p>
+
+    <p>This specification, <em>RDF 1.1 Concepts and Abstract Syntax</em>,
+    defines a data model and related terminology for use in
+    other specifications, such as
+    <a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">concrete RDF syntaxes</a>,
+    API specifications, and query languages.
+    Implementations cannot directly conform to
+    <em>RDF 1.1 Concepts and Abstract Syntax</em>,
+    but can conform to such other specifications that normatively
+    reference terms defined here.</p>
+</section>
+
+
+<section id="section-rdf-graph" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <!--OddPage--><h2 aria-level="1" role="heading" id="h2_section-rdf-graph"><span class="secno">3. </span>RDF Graphs</h2>
+
+    <p>An <dfn id="dfn-rdf-graph">RDF graph</dfn> is a set of
+    <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">RDF triples</a>.</p>
+
+
+<section id="section-triples" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-triples"><span class="secno">3.1 </span>Triples</h3>
+
+    <p>An <dfn id="dfn-rdf-triple">RDF triple</dfn> consists of three components:</p>
+
+    <ul>
+      <li>the <dfn id="dfn-subject">subject</dfn>, which is an
+      <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a <a href="#dfn-blank-node" class="internalDFN">blank node</a></li>
+
+      <li>the <dfn id="dfn-predicate">predicate</dfn>, which is an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a></li>
+
+      <li>the <dfn id="dfn-object">object</dfn>, which is an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>,
+      a <a href="#dfn-literal" class="internalDFN">literal</a> or a <a href="#dfn-blank-node" class="internalDFN">blank node</a></li>
+    </ul>
+
+    <p>An RDF triple is conventionally written in the order subject,
+    predicate, object.</p>
+
+    <p>The set of <dfn title="node" id="dfn-node">nodes</dfn> of an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>
+    is the set of subjects and objects of triples in the graph.
+    It is possible for a predicate <abbr title="Internationalized Resource Identifier">IRI</abbr> to also occur as a node in
+    the same graph.</p>
+
+    <p><a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>, <a title="literal" href="#dfn-literal" class="internalDFN">literals</a> and
+    <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a> are collectively known as
+    <dfn title="RDF term" id="dfn-rdf-term">RDF terms</dfn>.</p>
+
+    <p><a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>, <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>
+    and <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a> are distinct and distinguishable.
+    For example, <code>http://example.org/</code> as a string literal
+    is neither equal to <code>http://example.org/</code> as an <abbr title="Internationalized Resource Identifier">IRI</abbr>,
+    nor to a blank node with the <a href="#dfn-blank-node-identifier" class="internalDFN">blank node identifier</a>
+    <code>http://example.org/</code>.</p>
+</section>
+
+
+<section id="section-IRIs" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-IRIs"><span class="secno">3.2 </span>IRIs</h3>
+
+    <p>An <dfn title="IRI" id="dfn-iri"><abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>
+    (Internationalized Resource Identifier) within an RDF graph
+    is a Unicode string [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] that conforms to the syntax
+    defined in RFC 3987 [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>].</p>
+
+    <p>IRIs in the RDF abstract syntax <em class="rfc2119" title="MUST">MUST</em> be absolute, and <em class="rfc2119" title="MAY">MAY</em>
+    contain a fragment identifier.</p>
+
+    <p><dfn id="dfn-iri-equality"><abbr title="Internationalized Resource Identifier">IRI</abbr> equality</dfn>:
+    Two IRIs are equal if and only if they are equivalent
+    under Simple String Comparison according to
+    <a href="http://tools.ietf.org/html/rfc3987#section-5.1">section 5.1</a>
+    of [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>]. Further normalization <em class="rfc2119" title="MUST NOT">MUST NOT</em> be performed when
+    comparing IRIs for equality.</p>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_1"><span>Note</span></div><div class="" id="note-iris">
+    <p><strong>URIs and IRIs:</strong>
+    IRIs are a generalization of
+    <dfn title="URI" id="dfn-uri"><abbr title="Uniform Resource Identifier">URI</abbr>s</dfn>
+    [<cite><a class="bibref" href="#bib-RFC3986">RFC3986</a></cite>] that permits a wider range of Unicode characters.
+    Every absolute <abbr title="Uniform Resource Identifier">URI</abbr> and URL is an <abbr title="Internationalized Resource Identifier">IRI</abbr>, but not every <abbr title="Internationalized Resource Identifier">IRI</abbr> is an <abbr title="Uniform Resource Identifier">URI</abbr>.
+    When IRIs are used in operations that are only
+    defined for URIs, they must first be converted according to
+    the mapping defined in
+    <a href="http://tools.ietf.org/html/rfc3987#section-3.1">section 3.1</a>
+    of [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>]. A notable example is retrieval over the HTTP
+    protocol. The mapping involves UTF-8 encoding of non-ASCII
+    characters, %-encoding of octets not allowed in URIs, and
+    Punycode-encoding of domain names.</p>
+
+    <p><strong>Relative IRIs:</strong>
+    Some <a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">concrete RDF syntaxes</a> permit
+    <dfn title="relative IRI" id="dfn-relative-iri">relative IRIs</dfn> as a convenient shorthand
+    that allows authoring of documents independently from their final
+    publishing location. Relative IRIs must be
+    <a href="http://tools.ietf.org/html/rfc3986#section-5.2">resolved
+    against</a> a <dfn id="dfn-base-iri">base <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn> to make them absolute.
+    Therefore, the RDF graph serialized in such syntaxes is well-defined only
+    if a <a href="http://tools.ietf.org/html/rfc3986#section-5.1">base <abbr title="Internationalized Resource Identifier">IRI</abbr>
+    can be established</a> [<cite><a class="bibref" href="#bib-RFC3986">RFC3986</a></cite>].</p>
+
+      <p><strong><abbr title="Internationalized Resource Identifier">IRI</abbr> normalization:</strong>
+      Interoperability problems can be avoided by minting
+      only IRIs that are normalized according to
+      <a href="http://tools.ietf.org/html/rfc3987#section-5">Section 5</a>
+      of [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>]. Non-normalized forms that are best avoided
+      include:</p>
+
+      <ul>
+        <li>Uppercase characters in scheme names and domain names</li>
+        <li>Percent-encoding of characters where it is not
+          required by <abbr title="Internationalized Resource Identifier">IRI</abbr> syntax</li>
+        <li>Explicitly stated HTTP default port
+          (<code>http://example.com:80/</code>);
+          <code>http://example.com/</code> is preferable</li>
+        <li>Completely empty path in HTTP IRIs
+          (<code>http://example.com</code>);
+          <code>http://example.com/</code> is preferable</li>
+        <li>“<code>/./</code>” or “<code>/../</code>” in the path
+          component of an <abbr title="Internationalized Resource Identifier">IRI</abbr></li>
+        <li>Lowercase hexadecimal letters within percent-encoding
+          triplets (“<code>%3F</code>” is preferable over
+          “<code>%3f</code>”)</li>
+        <li>Punycode-encoding of Internationalized Domain Names
+          in IRIs</li>
+        <li>IRIs that are not in Unicode Normalization
+          Form C [<cite><a class="bibref" href="#bib-NFC">NFC</a></cite>]</li>
+      </ul>
+    </div></div>
+</section>
+
+
+<section id="section-Graph-Literal" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-Graph-Literal"><span class="secno">3.3 </span>Literals</h3>
+
+    <p>Literals are used for values such as strings, numbers, and dates.</p>
+
+    <p>A <dfn id="dfn-literal">literal</dfn> in an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> consists of two or three
+      elements:</p>
+
+    <ul>
+      <li>a <dfn id="dfn-lexical-form">lexical form</dfn>, being a Unicode [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] string,
+        which <em class="rfc2119" title="SHOULD">SHOULD</em> be in Normal Form&nbsp;C [<cite><a class="bibref" href="#bib-NFC">NFC</a></cite>],</li>
+      <li>a <dfn id="dfn-datatype-iri">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>, being an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+        identifying a datatype that determines how the lexical form maps
+        to a <a href="#dfn-literal-value" class="internalDFN">literal value</a>, and</li>
+      <li>if and only if the <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> is
+        <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#langString</code>, a
+        non-empty <dfn id="dfn-language-tag">language tag</dfn> as defined by [<cite><a class="bibref" href="#bib-BCP47">BCP47</a></cite>]. The
+        language tag <em class="rfc2119" title="MUST">MUST</em> be well-formed according to
+        <a href="http://tools.ietf.org/html/bcp47#section-2.2.9">section 2.2.9</a>
+        of [<cite><a class="bibref" href="#bib-BCP47">BCP47</a></cite>].</li>
+    </ul>
+
+    <p>A literal is a <dfn id="dfn-language-tagged-string">language-tagged string</dfn> if the third element
+      is present. Lexical representations of language tags <em class="rfc2119" title="MAY">MAY</em> be converted
+      to lower case. The value space of language tags is always in lower
+      case.</p>
+
+    <p>Please note that concrete syntaxes <em class="rfc2119" title="MAY">MAY</em> support
+      <dfn title="simple literal" id="dfn-simple-literal">simple literals</dfn> consisting of only a
+      <a href="#dfn-lexical-form" class="internalDFN">lexical form</a> without any <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> or <a href="#dfn-language-tag" class="internalDFN">language tag</a>.
+      Simple literals are syntactic sugar for abstract syntax
+      <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>
+      with the <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+      <code>http://www.w3.org/2001/XMLSchema#string</code>. Similarly, most
+      concrete syntaxes represent
+      <a title="language-tagged string" href="#dfn-language-tagged-string" class="internalDFN">language-tagged strings</a> without
+      the <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> because it always equals
+      <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#langString</code>.</p>
+
+    <p>The <dfn id="dfn-literal-value">literal value</dfn> associated with a <a href="#dfn-literal" class="internalDFN">literal</a> is:</p>
+
+    <ol>
+      <li>If the literal is a <a href="#dfn-language-tagged-string" class="internalDFN">language-tagged string</a>,
+        then the literal value is a pair consisting of its <a href="#dfn-lexical-form" class="internalDFN">lexical form</a>
+        and its <a href="#dfn-language-tag" class="internalDFN">language tag</a>, in that order.</li>
+
+      <li>If the literal's <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> is in the set of
+        <a href="#dfn-recognized-datatype-iris" class="internalDFN">recognized datatype IRIs</a>, let <var>d</var> be the
+        <a href="#dfn-referent" class="internalDFN">referent</a> of the datatype <abbr title="Internationalized Resource Identifier">IRI</abbr>.
+        <ol>
+          <li>If the literal's <a href="#dfn-lexical-form" class="internalDFN">lexical form</a> is in the <a href="#dfn-lexical-space" class="internalDFN">lexical space</a>
+            of <var>d</var>, then the literal value is the result of applying
+            the <a href="#dfn-lexical-to-value-mapping" class="internalDFN">lexical-to-value mapping</a> of <var>d</var> to the
+            <a href="#dfn-lexical-form" class="internalDFN">lexical form</a>.</li>
+          <li>Otherwise, the literal is ill-typed and no literal value can be
+             associated with the literal. Such a case produces a semantic
+             inconsistency but is not <em>syntactically</em> ill-formed.
+             Implementations <em class="rfc2119" title="MUST">MUST</em> accept ill-typed literals and produce RDF
+             graphs from them. Implementations <em class="rfc2119" title="MAY">MAY</em> produce warnings when
+             encountering ill-typed literals.</li>
+        </ol>
+      </li>
+      <li>If the literal's <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a> is <em>not</em> in the set of
+        <a href="#dfn-recognized-datatype-iris" class="internalDFN">recognized datatype IRIs</a>, then the literal value is
+        not defined by this specification.</li>
+    </ol>
+
+    <p><dfn id="dfn-literal-term-equality">Literal term equality</dfn>: Two literals are term-equal (the same
+      RDF literal) if and only if the two <a title="lexical form" href="#dfn-lexical-form" class="internalDFN">lexical forms</a>,
+      the two <a title="datatype IRI" href="#dfn-datatype-iri" class="internalDFN">datatype IRIs</a>, and the two
+      <a title="language tag" href="#dfn-language-tag" class="internalDFN">language tags</a> (if any) compare equal,
+      character by character. Thus, two literals can have the same value
+      without being the same RDF term. For example:</p>
+
+    <pre>      "1"^^xs:integer
+      "01"^^xs:integer
+    </pre>
+
+    <p>denote the same <a title="literal value" href="#dfn-literal-value" class="internalDFN">value</a>, but are not the
+      same literal <a title="RDF Term" href="#dfn-rdf-term" class="internalDFN">RDF terms</a> and are not
+      <a title="literal term equality" href="#dfn-literal-term-equality" class="internalDFN">term-equal</a> because their
+      <a href="#dfn-lexical-form" class="internalDFN">lexical form</a> differs.</p>
+</section>
+
+
+<section id="section-blank-nodes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-blank-nodes"><span class="secno">3.4 </span>Blank Nodes</h3>
+
+    <p><dfn title="blank node" id="dfn-blank-node">Blank nodes</dfn> are disjoint from
+    <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> and <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>.  Otherwise,
+    the set of possible blank nodes is arbitrary.  RDF makes no reference to
+    any internal structure of blank nodes.</p>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_2"><span>Note</span></div><p class="" id="note-bnode-id">
+    <dfn title="blank node identifier" id="dfn-blank-node-identifier">Blank node identifiers</dfn>
+    are local identifiers that are used in some
+    <a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">concrete RDF syntaxes</a>
+    or RDF store implementations.
+    They are always locally scoped to the file or RDF store,
+    and are <em>not</em> persistent or portable identifiers
+    for blank nodes. Blank node identifiers are <em>not</em>
+    part of the RDF abstract syntax, but are entirely dependent
+    on the concrete syntax or implementation. The syntactic restrictions
+    on blank node identifiers, if any, therefore also depend on
+    the concrete RDF syntax or implementation.  Implementations that handle blank node
+    identifiers in concrete syntaxes need to be careful not to create the
+    same blank node from multiple occurrences of the same blank node identifier
+    except in situations where this is supported by the syntax.</p></div>
+</section>
+
+
+<section id="section-skolemization" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-skolemization"><span class="secno">3.5 </span>Replacing Blank Nodes with IRIs</h3>
+
+    <p>Blank nodes do not have identifiers in the RDF abstract syntax. The
+    <a title="blank node identifier" href="#dfn-blank-node-identifier" class="internalDFN">blank node identifiers</a> introduced
+    by some concrete syntaxes have only
+    local scope and are purely an artifact of the serialization.</p>
+
+    <p>In situations where stronger identification is needed, systems <em class="rfc2119" title="MAY">MAY</em>
+    systematically replace some or all of the blank nodes in an RDF graph
+    with <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>.  Systems wishing to do this <em class="rfc2119" title="SHOULD">SHOULD</em>
+    mint a new, globally
+    unique <abbr title="Internationalized Resource Identifier">IRI</abbr> (a <dfn id="dfn-skolem-iri">Skolem <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>) for each blank node so replaced.</p>
+
+    <p>This transformation does not appreciably change the meaning of an
+    RDF graph, provided that the Skolem IRIs do not occur anywhere else.
+    It does however permit the possibility of other graphs
+    subsequently using the Skolem IRIs, which is not possible
+    for blank nodes.</p>
+
+    <p>Systems may wish to mint Skolem IRIs in such a way that they can
+    recognize the IRIs as having been introduced solely to replace blank
+    nodes. This allows a system to map IRIs back to blank nodes
+    if needed.</p>
+
+    <p>Systems that want Skolem IRIs to be recognizable outside of the system
+    boundaries <em class="rfc2119" title="SHOULD">SHOULD</em> use a well-known <abbr title="Internationalized Resource Identifier">IRI</abbr> [<cite><a class="bibref" href="#bib-RFC5785">RFC5785</a></cite>] with the registered
+    name <code>genid</code>. This is an <abbr title="Internationalized Resource Identifier">IRI</abbr> that uses the HTTP or HTTPS scheme,
+    or another scheme that has been specified to use well-known IRIs; and whose
+    path component starts with <code>/.well-known/genid/</code>.
+
+    </p><p>For example, the authority responsible for the domain
+    <code>example.com</code> could mint the following recognizable Skolem <abbr title="Internationalized Resource Identifier">IRI</abbr>:</p>
+
+    <pre>http://example.com/.well-known/genid/d26a2d0e98334696f4ad70a677abc1f6</pre>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_3"><span>Note</span></div><p class="">RFC 5785 [<cite><a class="bibref" href="#bib-RFC5785">RFC5785</a></cite>] only specifies well-known URIs,
+    not IRIs. For the purpose of this document, a well-known <abbr title="Internationalized Resource Identifier">IRI</abbr> is any
+    <abbr title="Internationalized Resource Identifier">IRI</abbr> that results in a well-known <abbr title="Uniform Resource Identifier">URI</abbr> after <abbr title="Internationalized Resource Identifier">IRI</abbr>-to-<abbr title="Uniform Resource Identifier">URI</abbr> mapping [<cite><a class="bibref" href="#bib-RFC3987">RFC3987</a></cite>].</p></div>
+</section>
+
+
+<section id="graph-isomorphism" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_graph-isomorphism"><span class="secno">3.6 </span>Graph Comparison</h3>
+
+    <p id="section-graph-equality">Two
+    <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a> <var>G</var> and <var>G'</var> are
+    <dfn title="graph isomorphism" id="dfn-graph-isomorphism">isomorphic</dfn> (that is, they have an identical
+    form) if there is a bijection <var>M</var> between the sets of nodes of the two
+    graphs, such that:</p>
+
+    <ol>
+      <li><var>M</var> maps blank nodes to blank nodes.</li>
+      <li><var>M(lit)=lit</var> for all <a title="literal" href="#dfn-literal" class="internalDFN">RDF literals</a> <var>lit</var> which
+      are nodes of <var>G</var>.</li>
+
+      <li><var>M(iri)=iri</var> for all <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> <var>iri</var>
+      which are nodes of <var>G</var>.</li>
+
+      <li>The triple <var>( s, p, o )</var> is in <var>G</var> if and
+      only if the triple <var>( M(s), p, M(o) )</var> is in
+      <var>G'</var></li>
+    </ol>
+
+    <p>See also: <a href="#dfn-iri-equality" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr> equality</a>, <a href="#dfn-literal-term-equality" class="internalDFN">literal term equality</a>.</p>
+
+    <p>With this definition, <var>M</var> shows how each blank node
+    in <var>G</var> can be replaced with
+    a new blank node to give <var>G'</var>. Graph isomorphism
+    is needed to support the RDF Test Cases [<cite><a class="bibref" href="#bib-RDF11-TESTCASES">RDF11-TESTCASES</a></cite>] specification.</p>
+</section>
+
+</section>
+
+
+<section id="section-dataset" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <!--OddPage--><h2 aria-level="1" role="heading" id="h2_section-dataset"><span class="secno">4. </span>RDF Datasets</h2>
+
+    <p>An <dfn id="dfn-rdf-dataset">RDF dataset</dfn> is a collection of
+      <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>, and comprises:</p>
+
+    <ul>
+      <li>Exactly one <dfn id="dfn-default-graph">default graph</dfn>, being an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>.
+        The default graph does not have a name and <em class="rfc2119" title="MAY">MAY</em> be empty.</li>
+      <li>Zero or more <dfn title="named graph" id="dfn-named-graph">named graphs</dfn>.
+        Each named graph is a pair consisting of an <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a blank node
+        (the <dfn id="dfn-graph-name">graph name</dfn>), and an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>.
+        Graph names are unique within an RDF dataset.</li>
+    </ul>
+
+    <p><a title="blank node" href="#dfn-blank-node" class="internalDFN">Blank nodes</a> can be shared between graphs
+      in an <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a>.</p>
+
+    <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_4"><span>Note</span></div><div class="" id="note-datasets">
+      <p>Despite the use of the word “name” in “<a href="#dfn-named-graph" class="internalDFN">named graph</a>”, the
+        <a href="#dfn-graph-name" class="internalDFN">graph name</a> is not required to <a href="#dfn-denote" class="internalDFN">denote</a> the graph. It is
+        merely syntactically paired with the graph. RDF does not place any
+        formal restrictions on what <a href="#dfn-resource" class="internalDFN">resource</a> the graph name may denote,
+        nor on the relationship between that resource and the graph.
+        A discussion of different RDF dataset semantics can be found in
+        [<cite><a class="bibref" href="#bib-RDF11-DATASETS">RDF11-DATASETS</a></cite>].</p>
+
+      <p>Some <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a> implementations do not
+        track empty <a title="named graph" href="#dfn-named-graph" class="internalDFN">named graphs</a>. Applications
+        can avoid interoperability issues by not ascribing importance to
+        the presence or absence of empty named graphs.</p>
+
+      <p>SPARQL 1.1 [<cite><a class="bibref" href="#bib-SPARQL11-OVERVIEW">SPARQL11-OVERVIEW</a></cite>] also defines the concept of an RDF
+				Dataset.  The definition of an RDF Dataset in SPARQL 1.1 and this
+				specification differ slightly in that this specification allows RDF
+				Graphs to be identified using either an <abbr title="Internationalized Resource Identifier">IRI</abbr> or a blank node.  SPARQL 1.1
+				Query Language only allows RDF Graphs to be identified using an <abbr title="Internationalized Resource Identifier">IRI</abbr>.
+				Existing SPARQL implementations might not allow blank nodes to be used
+				to identify RDF Graphs for some time, so their use can cause
+				interoperability problems.
+        <a href="#section-skolemization">Skolemizing</a> blank nodes used as
+        graph names can be used to overcome these interoperability problems.</p>
+    </div></div>
+
+<section id="section-dataset-isomorphism" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-dataset-isomorphism"><span class="secno">4.1 </span>RDF Dataset Comparison</h3>
+
+    <p id="section-dataset-equality">Two <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF datasets</a>
+      (the RDF dataset <var>D1</var> with default graph <var>DG1</var> and any named
+      graph <var>NG1</var> and the RDF dataset <var>D2</var> with default graph
+      <var>DG2</var> and any named graph <var>NG2</var>)
+      are <dfn title="dataset isomorphism" id="dfn-dataset-isomorphism">dataset-isomorphic</dfn> if and only if
+      there is a bijection <var>M</var> between the nodes, triples and graphs in
+      <var>D1</var> and those in <var>D2</var> such that:</p>
+
+    <ol>
+      <li><var>M</var> maps blank nodes to blank nodes;</li>
+      <li><var>M</var> is the identity map on literals and URIs;</li>
+      <li>For every triple &lt;s p o&gt;, <var>M</var>(&lt;s, p, o&gt;)=
+        &lt;<var>M(s)</var>, <var>M(p)</var>, <var>M(o)</var>&gt;;</li>
+      <li>For every graph <var>G</var>={t1, ..., tn},
+        <var>M(G)</var>={<var>M(t1)</var>, ..., <var>M(tn)</var>};</li>
+      <li><var>DG2</var> = <var>M(DG1)</var>; and</li>
+      <li>&lt;n, G&gt; is in <var>NG1</var> if and only if
+        &lt;<var>M(n)</var>, <var>M(G)</var>&gt; is in <var>NG2</var>.
+    </li></ol>
+
+</section>
+
+<section id="section-dataset-conneg" class="informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-dataset-conneg"><span class="secno">4.2 </span>Content Negotiation of RDF Datasets</h3><p><em>This section is non-normative.</em></p>
+
+    <p>Web resources may have multiple representations that are made available via
+    <a href="http://www.w3.org/TR/webarch/#frag-coneg">content negotiation</a>
+    [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>].  A representation may be returned in an RDF serialization
+    format that supports the expression of both <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF datasets</a> and
+    <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>.  If an <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF dataset</a>
+    is returned and the consumer is expecting an <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>,
+    the consumer is expected to use the <a title="RDF Dataset" href="#dfn-rdf-dataset" class="internalDFN">RDF dataset's</a> default graph.</p>
+
+</section>
+
+</section>
+
+
+<section id="section-Datatypes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <!--OddPage--><h2 aria-level="1" role="heading" id="h2_section-Datatypes"><span class="secno">5. </span>Datatypes</h2>
+
+    <p>Datatypes are used with RDF <a title="literal" href="#dfn-literal" class="internalDFN">literals</a>
+    to represent values such as strings, numbers and dates.
+    The datatype abstraction used in RDF is compatible with XML Schema
+    [<cite><a class="bibref" href="#bib-XMLSCHEMA11-2">XMLSCHEMA11-2</a></cite>]. Any datatype definition that conforms
+    to this abstraction <em class="rfc2119" title="MAY">MAY</em> be used in RDF, even if not defined
+    in terms of XML Schema. RDF re-uses many of the XML Schema
+    built-in datatypes, and defines two additional non-normative datatypes,
+    <code><a href="#dfn-rdf-html" class="internalDFN">rdf:HTML</a></code> and <code><a href="#dfn-rdf-xmlliteral" class="internalDFN">rdf:XMLLiteral</a></code>.
+    The list of datatypes supported by an implementation is determined
+    by its <a href="#dfn-recognized-datatype-iris" class="internalDFN">recognized datatype IRIs</a>.</p>
+
+    <p>A <dfn id="dfn-datatype">datatype</dfn> consists of a <a href="#dfn-lexical-space" class="internalDFN">lexical space</a>,
+    a <a href="#dfn-value-space" class="internalDFN">value space</a> and a <a href="#dfn-lexical-to-value-mapping" class="internalDFN">lexical-to-value mapping</a>, and
+    is denoted by one or more <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>.</p>
+
+<p>The <dfn id="dfn-lexical-space">lexical space</dfn> of a datatype is a set of Unicode [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] strings.</p>
+
+    <p>The <dfn id="dfn-lexical-to-value-mapping">lexical-to-value mapping</dfn> of a datatype is a set of
+    pairs whose first element belongs to the <a href="#dfn-lexical-space" class="internalDFN">lexical space</a>,
+    and the second element belongs to the <dfn id="dfn-value-space">value space</dfn>
+    of the datatype. Each member of the lexical space is paired with exactly
+    one value, and is a <em>lexical representation</em>
+    of that value. The mapping can be seen as a function
+    from the lexical space to the value space.</p>
+
+    <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_5"><span>Note</span></div><p class=""><a title="language-tagged string" href="#dfn-language-tagged-string" class="internalDFN">Language-tagged
+    strings</a> have the <a href="#dfn-datatype-iri" class="internalDFN">datatype <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+    <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#langString</code>.
+    No datatype is formally defined for this <abbr title="Internationalized Resource Identifier">IRI</abbr> because the definition
+    of <a title="datatype" href="#dfn-datatype" class="internalDFN">datatypes</a> does not accommodate
+    <a title="language tag" href="#dfn-language-tag" class="internalDFN">language tags</a> in the <a href="#dfn-lexical-space" class="internalDFN">lexical space</a>.
+    The <a href="#dfn-value-space" class="internalDFN">value space</a> associated with this datatype <abbr title="Internationalized Resource Identifier">IRI</abbr> is the set
+    of all pairs of strings and language tags.</p></div>
+
+    <p>For example, the XML Schema datatype <code>xsd:boolean</code>,
+    where each member of the <a href="#dfn-value-space" class="internalDFN">value space</a> has two lexical
+    representations, is defined as follows:</p>
+
+    <dl>
+    <dt>Lexical space:</dt>
+    <dd>{“<code>true</code>”, “<code>false</code>”, “<code>1</code>”, “<code>0</code>”}</dd>
+    <dt>Value space:</dt>
+    <dd>{<em><strong>true</strong></em>, <em><strong>false</strong></em>}</dd>
+    <dt>Lexical-to-value mapping</dt>
+    <dd>{
+        &lt;“<code>true</code>”, <em><strong>true</strong></em>&gt;,
+        &lt;“<code>false</code>”, <em><strong>false</strong></em>&gt;,
+        &lt;“<code>1</code>”, <em><strong>true</strong></em>&gt;,
+        &lt;“<code>0</code>”, <em><strong>false</strong></em>&gt;,
+        }</dd>
+    </dl>
+
+    <p>The <a title="literal" href="#dfn-literal" class="internalDFN">literals</a> that can be defined using this
+    datatype are:</p>
+
+    <table class="simple">
+      <caption>This table lists the literals of type xsd:boolean.</caption>
+      <tbody><tr>
+        <th>Literal</th>
+        <th>Value</th>
+      </tr>
+      <tr>
+        <td>&lt;“<code>true</code>”, <code>xsd:boolean</code>&gt;</td>
+        <td><em><strong>true</strong></em></td>
+      </tr>
+      <tr>
+        <td>&lt;“<code>false</code>”, <code>xsd:boolean</code>&gt;</td>
+        <td><em><strong>false</strong></em></td>
+      </tr>
+      <tr>
+        <td>&lt;“<code>1</code>”, <code>xsd:boolean</code>&gt;</td>
+        <td><em><strong>true</strong></em></td>
+      </tr>
+      <tr>
+        <td>&lt;“<code>0</code>”, <code>xsd:boolean</code>&gt;</td>
+        <td><em><strong>false</strong></em></td>
+      </tr>
+    </tbody></table>
+
+
+<section id="xsd-datatypes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_xsd-datatypes"><span class="secno">5.1 </span>The XML Schema Built-in Datatypes</h3>
+
+    <p><a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a> of the form
+    <code>http://www.w3.org/2001/XMLSchema#<em>xxx</em></code>,
+    where <code><em>xxx</em></code>
+    is the name of a datatype, denote the built-in datatypes defined in
+    <em><a href="http://www.w3.org/TR/xmlschema11-2/">XML Schema 1.1 Part 2:
+    Datatypes</a></em> [<cite><a class="bibref" href="#bib-XMLSCHEMA11-2">XMLSCHEMA11-2</a></cite>]. The XML Schema built-in types
+    listed in the following table are the
+    <dfn id="dfn-rdf-compatible-xsd-types">RDF-compatible XSD types</dfn>. Their use is <em class="rfc2119" title="RECOMMENDED">RECOMMENDED</em>.</p>
+
+    <p>Readers might note that the xsd:hexBinary and xsd:base64Binary
+    datatypes are the only safe datatypes for transferring binary
+    information.</p>
+
+    <table class="simple">
+      <caption>A list of the RDF-compatible XSD types, with short descriptions"</caption>
+    <tbody><tr><th></th><th>Datatype</th><th>Value space (informative)</th></tr>
+
+    <tr><th rowspan="4">Core types</th><td><a href="http://www.w3.org/TR/xmlschema11-2/#string"><code>xsd:string</code></a></td><td>Character strings (but not all Unicode character strings)</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#boolean"><code>xsd:boolean</code></a></td><td>true, false</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#decimal"><code>xsd:decimal</code></a></td><td>Arbitrary-precision decimal numbers</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#integer"><code>xsd:integer</code></a></td><td>Arbitrary-size integer numbers</td></tr>
+
+    <tr><th rowspan="2">IEEE floating-point<br>numbers</th>
+        <td><a href="http://www.w3.org/TR/xmlschema11-2/#double"><code>xsd:double</code></a></td><td>64-bit floating point numbers incl. ±Inf, ±0, NaN</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#float"><code>xsd:float</code></a></td><td>32-bit floating point numbers incl. ±Inf, ±0, NaN</td></tr>
+
+    <tr><th rowspan="4">Time and date</th>
+        <td><a href="http://www.w3.org/TR/xmlschema11-2/#date"><code>xsd:date</code></a></td><td>Dates (yyyy-mm-dd) with or without timezone</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#time"><code>xsd:time</code></a></td><td>Times (hh:mm:ss.sss…) with or without timezone</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#dateTime"><code>xsd:dateTime</code></a></td><td>Date and time with or without timezone</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#dateTimeStamp"><code>xsd:dateTimeStamp</code></a></td><td>Date and time with required timezone</td></tr>
+
+    <tr><th rowspan="8">Recurring and<br>partial dates</th>
+        <td><a href="http://www.w3.org/TR/xmlschema11-2/#gYear"><code>xsd:gYear</code></a></td><td>Gregorian calendar year</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#gMonth"><code>xsd:gMonth</code></a></td><td>Gregorian calendar month</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#gDay"><code>xsd:gDay</code></a></td><td>Gregorian calendar day of the month</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#gYearMonth"><code>xsd:gYearMonth</code></a></td><td>Gregorian calendar year and month</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#gMonthDay"><code>xsd:gMonthDay</code></a></td><td>Gregorian calendar month and day</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#duration"><code>xsd:duration</code></a></td><td>Duration of time</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#yearMonthDuration"><code>xsd:yearMonthDuration</code></a></td><td>Duration of time (months and years only)</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#dayTimeDuration"><code>xsd:dayTimeDuration</code></a></td><td>Duration of time (days, hours, minutes, seconds only)</td></tr>
+
+    <tr><th rowspan="12">Limited-range<br>integer numbers</th>
+        <td><a href="http://www.w3.org/TR/xmlschema11-2/#byte"><code>xsd:byte</code></a></td><td>-128…+127 (8 bit)</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#short"><code>xsd:short</code></a></td><td>-32768…+32767 (16 bit)</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#int"><code>xsd:int</code></a></td><td>-2147483648…+2147483647 (32 bit)</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#long"><code>xsd:long</code></a></td><td>-9223372036854775808…+9223372036854775807 (64 bit)</td></tr>
+
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#unsignedByte"><code>xsd:unsignedByte</code></a></td><td>0…255 (8 bit)</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#unsignedShort"><code>xsd:unsignedShort</code></a></td><td>0…65535 (16 bit)</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#unsignedInt"><code>xsd:unsignedInt</code></a></td><td>0…4294967295 (32 bit)</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#unsignedLong"><code>xsd:unsignedLong</code></a></td><td>0…18446744073709551615 (64 bit)</td></tr>
+
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#positiveInteger"><code>xsd:positiveInteger</code></a></td><td>Integer numbers &gt;0</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#nonNegativeInteger"><code>xsd:nonNegativeInteger</code></a></td><td>Integer numbers ≥0</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#negativeInteger"><code>xsd:negativeInteger</code></a></td><td>Integer numbers &lt;0</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#nonPositiveInteger"><code>xsd:nonPositiveInteger</code></a></td><td>Integer numbers ≤0</td></tr>
+
+    <tr><th rowspan="2">Encoded binary data</th>
+        <td><a href="http://www.w3.org/TR/xmlschema11-2/#hexBinary"><code>xsd:hexBinary</code></a></td><td>Hex-encoded binary data</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#base64Binary"><code>xsd:base64Binary</code></a></td><td>Base64-encoded binary data</td></tr>
+
+    <tr><th rowspan="7">Miscellaneous<br>XSD types</th>
+        <td><a href="http://www.w3.org/TR/xmlschema11-2/#anyURI"><code>xsd:anyURI</code></a></td><td>Absolute or relative URIs and IRIs</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#language"><code>xsd:language</code></a></td><td>Language tags per [<cite><a class="bibref" href="#bib-BCP47">BCP47</a></cite>]</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#normalizedString"><code>xsd:normalizedString</code></a></td><td>Whitespace-normalized strings</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#token"><code>xsd:token</code></a></td><td>Tokenized strings</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#NMTOKEN"><code>xsd:NMTOKEN</code></a></td><td>XML NMTOKENs</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#Name"><code>xsd:Name</code></a></td><td>XML Names</td></tr>
+    <tr><td><a href="http://www.w3.org/TR/xmlschema11-2/#NCName"><code>xsd:NCName</code></a></td><td>XML NCNames</td></tr>
+    </tbody></table>
+
+    <p>The other built-in XML Schema datatypes are unsuitable
+      for various reasons and <em class="rfc2119" title="SHOULD NOT">SHOULD NOT</em> be used:</p>
+
+    <ul>
+      <li><a href="http://www.w3.org/TR/xmlschema11-2/#QName"><code>xsd:QName</code></a>
+        and <a href="http://www.w3.org/TR/xmlschema11-2/#ENTITY"><code>xsd:ENTITY</code></a>
+        require an enclosing XML document context.</li>
+      <li><a href="http://www.w3.org/TR/xmlschema11-2/#ID"><code>xsd:ID</code></a>
+        and <a href="http://www.w3.org/TR/xmlschema11-2/#IDREF"><code>xsd:IDREF</code></a>
+        are for cross references within an XML document.</li>
+      <li><a href="http://www.w3.org/TR/xmlschema11-2/#NOTATION"><code>xsd:NOTATION</code></a>
+        is not intended for direct use.</li>
+      <li><a href="http://www.w3.org/TR/xmlschema11-2/#IDREFS"><code>xsd:IDREFS</code></a>,
+        <a href="http://www.w3.org/TR/xmlschema11-2/#ENTITIES"><code>xsd:ENTITIES</code></a>
+        and <a href="http://www.w3.org/TR/xmlschema11-2/#NMTOKENS"><code>xsd:NMTOKENS</code></a>
+        are sequence-valued datatypes which do not fit the RDF <a href="#dfn-datatype" class="internalDFN">datatype</a>
+        model.</li>
+    </ul>
+
+</section>
+
+
+<section id="section-html" class="informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-html"><span class="secno">5.2 </span>The <code>rdf:HTML</code> Datatype</h3><p><em>This section is non-normative.</em></p>
+
+    <p>RDF provides for HTML content as a possible <a href="#dfn-literal-value" class="internalDFN">literal value</a>.
+      This allows markup in literal values. Such content is indicated
+      in an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> using a <a href="#dfn-literal" class="internalDFN">literal</a> whose <a href="#dfn-datatype" class="internalDFN">datatype</a>
+      is set to <code><dfn id="dfn-rdf-html">rdf:HTML</dfn></code>. This datatype is defined
+      as non-normative because it depends on [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>], a specification that
+      has not yet reached <abbr title="World Wide Web Consortium">W3C</abbr> Recommendation status.</p>
+
+    <p>The <code>rdf:HTML</code> datatype is defined as follows:</p>
+
+    <dl>
+      <dt>The <abbr title="Internationalized Resource Identifier">IRI</abbr> denoting this datatype</dt>
+      <dd>is <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#HTML</code>.</dd>
+
+      <dt>The lexical space</dt>
+      <dd>is the set of Unicode [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] strings.</dd>
+
+      <dt>The value space</dt>
+      <dd>is a set of DOM
+        <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
+        nodes [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>]. Two
+        <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
+        nodes <em>A</em> and <em>B</em> are considered equal if and only if
+        the DOM method
+        <code><em>A</em>.<a href="http://www.w3.org/TR/dom/#dom-node-isequalnode">isEqualNode</a>(<em>B</em>)</code>
+        [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>] returns <code>true</code>.</dd>
+
+      <dt>The lexical-to-value mapping</dt>
+      <dd>
+        <p>Each member of the lexical space is associated with the result
+          of applying the following algorithm:</p>
+        <ul>
+          <li>Let <code>domnodes</code> be the list of <a href="http://www.w3.org/TR/dom/#node">DOM nodes</a> [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>]
+            that result from applying the
+            <a href="http://www.w3.org/TR/html5/syntax.html#parsing-html-fragments">HTML fragment parsing algorithm</a> [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>]
+            to the input string, without a context element.</li>
+          <li>Let <code>domfrag</code> be a DOM
+            <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a> [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>]
+            whose <code>childNodes</code> attribute is equal to <code>domnodes</code></li>
+            <li>Return <code>domfrag.<a href="http://www.w3.org/TR/dom/#dom-node-normalize">normalize</a>()</code></li>
+        </ul>
+      </dd>
+    </dl>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_6"><span>Note</span></div><p class="" id="note-html">
+      Any language annotation (<code>lang="…"</code>) or
+      XML namespaces (<code>xmlns</code>) desired in the HTML content
+      must be included explicitly in the HTML literal. Relative URLs
+      in attributes such as <code>href</code> do not have a well-defined
+      base URL and are best avoided.
+      RDF applications may use additional equivalence relations,
+      such as that which relates an <code>xsd:string</code> with an
+      <code>rdf:HTML</code> literal corresponding to a single text node
+      of the same string.</p></div>
+</section>
+
+<section id="section-XMLLiteral" class="informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <h3 aria-level="2" role="heading" id="h3_section-XMLLiteral"><span class="secno">5.3 </span>The <code>rdf:XMLLiteral</code> Datatype</h3><p><em>This section is non-normative.</em></p>
+
+    <p>RDF provides for XML content as a possible <a href="#dfn-literal-value" class="internalDFN">literal value</a>.
+      Such content is indicated in an <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> using a <a href="#dfn-literal" class="internalDFN">literal</a>
+      whose <a href="#dfn-datatype" class="internalDFN">datatype</a> is set to <code><dfn id="dfn-rdf-xmlliteral">rdf:XMLLiteral</dfn></code>.
+      This datatype is defined as non-normative because it depends on [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>],
+      a specification that has not yet reached <abbr title="World Wide Web Consortium">W3C</abbr> Recommendation status.</p>
+
+    <p>The <code>rdf:XMLLiteral</code> datatype is defined as follows:</p>
+
+    <dl>
+      <dt id="XMLLiteral-uri">The <abbr title="Internationalized Resource Identifier">IRI</abbr> denoting this <a href="#dfn-datatype" class="internalDFN">datatype</a></dt>
+      <dd>is <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>.</dd>
+
+      <dt id="XMLLiteral-lexical-space">The <a href="#dfn-lexical-space" class="internalDFN">lexical space</a></dt>
+      <dd>is the set of all strings which are well-balanced, self-contained
+        <a href="http://www.w3.org/TR/2000/REC-xml-20001006#NT-content">XML content</a>
+        [<cite><a class="bibref" href="#bib-XML10">XML10</a></cite>]; and for which embedding between an arbitrary
+        XML start tag and an end tag yields a document conforming to
+        <a href="http://www.w3.org/TR/1999/REC-xml-names-19990114/">XML Namespaces</a>
+        [<cite><a class="bibref" href="#bib-XML-NAMES">XML-NAMES</a></cite>].</dd>
+
+      <dt id="XMLLiteral-value-space">The <a href="#dfn-value-space" class="internalDFN">value space</a></dt>
+        <dd>is a set of DOM
+        <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
+        nodes [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>]. Two
+        <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
+        nodes <em>A</em> and <em>B</em> are considered equal if and only if the DOM method
+        <code><em>A</em>.<a href="http://www.w3.org/TR/dom/#dom-node-isequalnode">isEqualNode</a>(<em>B</em>)</code>
+        returns <code>true</code>.</dd>
+
+      <dt id="XMLLiteral-mapping">The <a href="#dfn-lexical-to-value-mapping" class="internalDFN">lexical-to-value mapping</a></dt>
+      <dd>
+        <p>Each member of the lexical space is associated with the result of applying the following algorithm:</p>
+        <ul>
+          <li>Let <code>domfrag</code> be a DOM
+            <a href="http://www.w3.org/TR/dom/#interface-documentfragment"><code>DocumentFragment</code></a>
+            node [<cite><a class="bibref" href="#bib-DOM4">DOM4</a></cite>] corresponding to the input string</li>
+          <li>Return <code>domfrag.<a href="http://www.w3.org/TR/dom/#dom-node-normalize">normalize</a>()</code></li>
+        </ul>
+      </dd>
+
+      <dt id="XMLLiteral-canonical">The canonical mapping</dt>
+      <dd>defines a
+        <a href="http://www.w3.org/TR/xmlschema11-2/#dt-canonical-mapping">canonical lexical form</a> [<cite><a class="bibref" href="#bib-XMLSCHEMA11-2">XMLSCHEMA11-2</a></cite>]
+        for each member of the value space. The <code>rdf:XMLLiteral</code> canonical mapping is the
+        <a href="http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718/#def-exclusive-XML-canonicalization-method">exclusive XML canonicalization method</a>
+        (<em>with comments, with empty
+        <a href="http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718/#def-InclusiveNamespaces-PrefixList">InclusiveNamespaces PrefixList</a></em>)
+        [<cite><a class="bibref" href="#bib-XML-EXC-C14N">XML-EXC-C14N</a></cite>].</dd>
+    </dl>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_7"><span>Note</span></div><p class="">Any XML namespace declarations (<code>xmlns</code>),
+      language annotation (<code>xml:lang</code>) or base <abbr title="Uniform Resource Identifier">URI</abbr> declarations
+      (<code>xml:base</code>) desired in the XML content must be included
+      explicitly in the XML literal. Note that some concrete RDF syntaxes
+      may define mechanisms for inheriting them from the context (e.g.,
+      <a href="http://www.w3.org/TR/rdf-syntax-grammar/#parseTypeLiteralPropertyElt"><code>@parseType="literal"</code></a>
+      in RDF/XML [<cite><a class="bibref" href="#bib-RDF11-XML">RDF11-XML</a></cite>]).</p></div>
+</section>
+
+<section id="datatype-iris">
+    <h3 aria-level="2" role="heading" id="h3_datatype-iris"><span class="secno">5.4 </span>Datatype IRIs</h3>
+
+    <p>Datatypes are identified by <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>. If
+      <var>D</var> is a set of IRIs which are used to refer to
+      datatypes, then the elements of <var>D</var> are called <dfn id="dfn-recognized-datatype-iris">recognized
+      datatype IRIs</dfn>. Recognized IRIs have fixed
+      <a href="#referents">referents</a>. If any <abbr title="Internationalized Resource Identifier">IRI</abbr> of the form
+      <code>http://www.w3.org/2001/XMLSchema#xxx</code> is recognized, it
+      <em class="rfc2119" title="MUST">MUST</em> refer to the RDF-compatible XSD type named <code>xsd:xxx</code> for
+      every XSD type listed in <a href="#xsd-datatypes">section 5.1</a>.
+      Furthermore, the following IRIs are allocated for non-normative
+      datatypes:
+
+    </p><ul>
+      <li>The <abbr title="Internationalized Resource Identifier">IRI</abbr> <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>
+        refers to the datatype <code><a href="#dfn-rdf-xmlliteral" class="internalDFN">rdf:XMLLiteral</a></code></li>
+      <li>The <abbr title="Internationalized Resource Identifier">IRI</abbr> <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#HTML</code>
+        refers to the datatype <code><a href="#dfn-rdf-html" class="internalDFN">rdf:HTML</a></code></li>
+    </ul>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_8"><span>Note</span></div><p class="">Semantic extensions of RDF might choose to
+      recognize other datatype IRIs
+      and require them to refer to a fixed datatype.  See the RDF
+      Semantics specification [<cite><a class="bibref" href="#bib-RDF11-MT">RDF11-MT</a></cite>] for more information on
+      semantic extensions.</p></div>
+
+    <p>RDF processors are not required to recognize datatype IRIs.
+      Any literal typed with an unrecognized <abbr title="Internationalized Resource Identifier">IRI</abbr> is treated just like
+      an unknown <abbr title="Internationalized Resource Identifier">IRI</abbr>, i.e. as referring to an unknown thing. Applications
+      <em class="rfc2119" title="MAY">MAY</em> give a warning message if they are unable to determine the
+      referent of an <abbr title="Internationalized Resource Identifier">IRI</abbr> used in a typed literal, but they <em class="rfc2119" title="SHOULD NOT">SHOULD NOT</em>
+      reject such RDF as either a syntactic or semantic error.</p><p>
+
+    </p><p>Other specifications <em class="rfc2119" title="MAY">MAY</em> impose additional constraints on
+      <a title="datatype IRI" href="#dfn-datatype-iri" class="internalDFN">datatype IRIs</a>, for example, require support
+      for certain datatypes.</p>
+
+    <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_9"><span>Note</span></div><p class="" id="note-custom-datatypes">The Web Ontology Language
+      [<cite><a class="bibref" href="#bib-OWL2-OVERVIEW">OWL2-OVERVIEW</a></cite>] offers facilities for formally defining
+      <a href="http://www.w3.org/TR/owl2-syntax/#Datatype_Definitions">custom
+      datatypes</a> that can be used with RDF. Furthermore, a practice for
+      identifying
+      <a href="http://www.w3.org/TR/swbp-xsch-datatypes/#sec-userDefined">
+      user-defined simple XML Schema datatypes</a>
+      is suggested in [<cite><a class="bibref" href="#bib-SWBP-XSCH-DATATYPES">SWBP-XSCH-DATATYPES</a></cite>]. RDF implementations
+      are not required to support either of these facilities.</p></div>
+</section>
+
+</section>
+
+
+<section id="section-fragID" class="informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+  <!--OddPage--><h2 aria-level="1" role="heading" id="h2_section-fragID"><span class="secno">6. </span>Fragment Identifiers</h2><p><em>This section is non-normative.</em></p>
+
+  <p>RDF uses <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>, which may include
+    <dfn id="dfn-fragment-identifiers">fragment identifiers</dfn>, as resource identifiers.
+    The semantics of fragment identifiers is
+    <a href="http://tools.ietf.org/html/rfc3986#section-3.5">defined in
+    RFC 3986</a> [<cite><a class="bibref" href="#bib-RFC3986">RFC3986</a></cite>]: They identify a secondary resource
+    that is usually a part of, view of, defined in, or described in
+    the primary resource, and the precise semantics depend on the set
+    of representations that might result from a retrieval action
+    on the primary resource.</p>
+
+  <p>This section discusses the handling of fragment identifiers
+    in representations that encode <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">RDF graphs</a>.</p>
+
+  <p>In RDF-bearing representations of a primary resource
+    <code>&lt;foo&gt;</code>,
+    the secondary resource identified by a fragment <code>bar</code>
+    is the <a href="#dfn-resource" class="internalDFN">resource</a> <a title="denote" href="#dfn-denote" class="internalDFN">denoted</a> by the
+    full <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> <code>&lt;foo#bar&gt;</code> in the <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a>.
+    Since IRIs in RDF graphs can denote anything, this can be
+    something external to the representation, or even external
+    to the web.</p>
+
+  <p>In this way, the RDF-bearing representation acts as an intermediary
+    between the web-accessible primary resource, and some set of possibly
+    non-web or abstract entities that the <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> may describe.</p>
+
+  <p>In cases where other specifications constrain the semantics of
+    fragment identifiers in RDF-bearing representations, the encoded
+    <a href="#dfn-rdf-graph" class="internalDFN">RDF graph</a> should use fragment identifiers in a way that is consistent
+    with these constraints. For example, in an HTML+RDFa document [<cite><a class="bibref" href="#bib-HTML-RDFA">HTML-RDFA</a></cite>],
+    the fragment <code>chapter1</code> may identify a document section
+    via the semantics of HTML's <code>@name</code> or <code>@id</code>
+    attributes. The <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> <code>&lt;#chapter1&gt;</code> should
+    then be taken to <a href="#dfn-denote" class="internalDFN">denote</a> that same section in any RDFa-encoded
+    <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">triples</a> within the same document.
+    Similarly, fragment identifiers should be used consistently in resources
+    with multiple representations that are made available via
+    <a href="http://www.w3.org/TR/webarch/#frag-coneg">content negotiation</a>
+    [<cite><a class="bibref" href="#bib-WEBARCH">WEBARCH</a></cite>]. For example, if the fragment <code>chapter1</code> identifies a
+    document section in an HTML representation of the primary resource, then the
+    <a title="IRI" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> <code>&lt;#chapter1&gt;</code> should be taken to
+    <a href="#dfn-denote" class="internalDFN">denote</a> that same section in all RDF-bearing representations of the
+    same primary resource.</p>
+</section>
+
+<section id="section-generalized-rdf" class="informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <!--OddPage--><h2 aria-level="1" role="heading" id="h2_section-generalized-rdf"><span class="secno">7. </span>Generalized RDF Triples, Graphs, and Datasets</h2><p><em>This section is non-normative.</em></p>
+
+    <p>It is sometimes convenient to loosen the requirements
+    on <a href="#dfn-rdf-triple" class="internalDFN">RDF triple</a>s.  For example, the completeness
+    of the RDFS entailment rules is easier to show with a
+    generalization of RDF triples.</p>
+
+    <p>A <dfn title="generalized RDF triple" id="dfn-generalized-rdf-triple">generalized RDF
+      triple</dfn> is a triple having a subject, a predicate,
+      and object, where each can be an <a title="iri" href="#dfn-iri" class="internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a
+      <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank node</a> or a
+      <a href="#dfn-literal" class="internalDFN">literal</a>. A
+      <dfn title="generalized RDF graph" id="dfn-generalized-rdf-graph">generalized RDF graph</dfn>
+      is a set of generalized RDF triples. A
+      <dfn title="generalized RDF dataset" id="dfn-generalized-rdf-dataset">generalized RDF dataset</dfn>
+      comprises a distinguished generalized RDF graph, and zero
+      or more pairs each associating an <abbr title="Internationalized Resource Identifier">IRI</abbr>, a blank node or a literal
+      to a generalized RDF graph.</p>
+
+
+    <p>Generalized RDF triples, graphs, and datasets differ
+      from normative RDF <a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">triples</a>,
+      <a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">graphs</a>, and
+      <a title="RDF dataset" href="#dfn-rdf-dataset" class="internalDFN">datasets</a> only
+      by allowing <a title="IRI" href="#dfn-iri" class="internalDFN">IRIs</a>,
+      <a title="blank node" href="#dfn-blank-node" class="internalDFN">blank nodes</a> and
+      <a title="literal" href="#dfn-literal" class="internalDFN">literals</a> to appear
+      in any position, i.e., as subject, predicate, object or graph names.</p>
+
+    <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_10"><span>Note</span></div><p class="" id="note-generalized-rdf"> Any users of
+    generalized RDF triples, graphs or datasets need to be
+    aware that these notions are non-standard extensions of
+    RDF and their use may cause interoperability problems.
+    There is no requirement on the part of any RDF tool to
+    accept, process, or produce anything beyond standard RDF
+    triples, graphs, and datasets. </p></div>
+
+</section>
+
+<section id="section-Acknowledgments" class="informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+  <!--OddPage--><h2 aria-level="1" role="heading" id="h2_section-Acknowledgments"><span class="secno">8. </span>Acknowledgments</h2><p><em>This section is non-normative.</em></p>
+
+  <p>The editors acknowledge valuable contributions from Thomas Baker,
+    Tim Berners-Lee, David Booth, Dan Brickley, Gavin Carothers, Jeremy Carroll,
+    Pierre-Antoine Champin, Dan Connolly, John Cowan, Martin J. Dürst,
+    Alex Hall, Steve Harris, Sandro Hawke, Pat Hayes, Ivan Herman, Peter F. Patel-Schneider,
+    Addison Phillips, Eric Prud'hommeaux, Nathan Rixham, Andy Seaborne, Leif Halvard Silli,
+    Guus Schreiber, Dominik Tomaszuk, and Antoine Zimmermann.</p>
+
+  <p>The membership of the RDF Working Group included Thomas Baker,
+    Scott Bauer, Dan Brickley, Gavin Carothers, Pierre-Antoine Champin,
+    Olivier Corby, Richard Cyganiak, Souripriya Das, Ian Davis, Lee Feigenbaum,
+    Fabien Gandon, Charles Greer, Alex Hall, Steve Harris, Sandro Hawke,
+    Pat Hayes, Ivan Herman, Nicholas Humfrey, Kingsley Idehen, Gregg Kellogg,
+    Markus Lanthaler, Arnaud Le Hors, Peter F. Patel-Schneider,
+    Eric Prud'hommeaux, Yves Raimond, Nathan Rixham, Guus Schreiber,
+    Andy Seaborne, Manu Sporny, Thomas Steiner, Ted Thibodeau, Mischa Tuffield,
+    William Waites, Jan Wielemaker, David Wood, Zhe Wu, and Antoine Zimmermann.</p>
+</section>
+
+
+<section class="appendix informative" id="changes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+    <!--OddPage--><h2 aria-level="1" role="heading" id="h2_changes"><span class="secno">A. </span>Changes between RDF 1.0 and RDF 1.1</h2><p><em>This section is non-normative.</em></p>
+
+    <p>A detailed overview of the differences between RDF versions&nbsp;1.0
+      and&nbsp;1.1 can be found in
+      <a href="http://www.w3.org/TR/rdf11-new/">What’s New in RDF&nbsp;1.1</a> [<cite><a class="bibref" href="#bib-RDF11-NEW">RDF11-NEW</a></cite>].</p>
+</section>
+
+
+
+
+<section id="references" class="appendix" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><!--OddPage--><h2 aria-level="1" role="heading" id="h2_references"><span class="secno">B. </span>References</h2><section id="normative-references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h3 aria-level="2" role="heading" id="h3_normative-references"><span class="secno">B.1 </span>Normative references</h3><dl class="bibliography" about=""><dt id="bib-BCP47">[BCP47]</dt><dd rel="dcterms:requires">A. Phillips; M. Davis. <a href="http://tools.ietf.org/html/bcp47"><cite>Tags for Identifying Languages</cite></a>. September 2009. IETF Best Current Practice. URL: <a href="http://tools.ietf.org/html/bcp47">http://tools.ietf.org/html/bcp47</a>
+</dd><dt id="bib-NFC">[NFC]</dt><dd rel="dcterms:requires">M. Davis, Ken Whistler. <a href="http://www.unicode.org/reports/tr15/"><cite>TR15, Unicode Normalization Forms.</cite></a>. 17 September 2010, URL: <a href="http://www.unicode.org/reports/tr15/">http://www.unicode.org/reports/tr15/</a>
+</dd><dt id="bib-RFC2119">[RFC2119]</dt><dd rel="dcterms:requires">S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key words for use in RFCs to Indicate Requirement Levels.</cite></a> March 1997. Internet RFC 2119.  URL: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a>
+</dd><dt id="bib-RFC3987">[RFC3987]</dt><dd rel="dcterms:requires">M. Dürst; M. Suignard. <a href="http://www.ietf.org/rfc/rfc3987.txt"><cite>Internationalized Resource Identifiers (IRIs)</cite></a>. January 2005. RFC. URL: <a href="http://www.ietf.org/rfc/rfc3987.txt">http://www.ietf.org/rfc/rfc3987.txt</a>
+</dd><dt id="bib-UNICODE">[UNICODE]</dt><dd rel="dcterms:requires"><a href="http://www.unicode.org/versions/latest/"><cite>The Unicode Standard</cite></a>. URL: <a href="http://www.unicode.org/versions/latest/">http://www.unicode.org/versions/latest/</a>
+</dd><dt id="bib-XMLSCHEMA11-2">[XMLSCHEMA11-2]</dt><dd rel="dcterms:requires">David Peterson; Sandy Gao; Ashok Malhotra; Michael Sperberg-McQueen; Henry Thompson; Paul V. Biron et al. <a href="http://www.w3.org/TR/xmlschema11-2/"><cite>W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes</cite></a>. 5 April 2012. W3C Recommendation. URL: <a href="http://www.w3.org/TR/xmlschema11-2/">http://www.w3.org/TR/xmlschema11-2/</a>
+</dd></dl></section><section id="informative-references" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter"><h3 aria-level="2" role="heading" id="h3_informative-references"><span class="secno">B.2 </span>Informative references</h3><dl class="bibliography" about=""><dt id="bib-COOLURIS">[COOLURIS]</dt><dd rel="dcterms:references">Leo Sauermann; Richard Cyganiak. <a href="http://www.w3.org/TR/cooluris"><cite>Cool URIs for the Semantic Web</cite></a>. 3 December 2008. W3C Note. URL: <a href="http://www.w3.org/TR/cooluris">http://www.w3.org/TR/cooluris</a>
+</dd><dt id="bib-DOM4">[DOM4]</dt><dd rel="dcterms:references">Anne van Kesteren; Aryeh Gregor; Ms2ger; Alex Russell; Robin Berjon. <a href="http://www.w3.org/TR/dom/"><cite>W3C DOM4</cite></a>. 7 November 2013. W3C Working Draft. URL: <a href="http://www.w3.org/TR/dom/">http://www.w3.org/TR/dom/</a>
+</dd><dt id="bib-HTML-RDFA">[HTML-RDFA]</dt><dd rel="dcterms:references">Manu Sporny. <a href="http://www.w3.org/TR/html-rdfa/"><cite>HTML+RDFa 1.1</cite></a>. 22 August 2013. W3C Recommendation. URL: <a href="http://www.w3.org/TR/html-rdfa/">http://www.w3.org/TR/html-rdfa/</a>
+</dd><dt id="bib-HTML5">[HTML5]</dt><dd rel="dcterms:references">Robin Berjon; Steve Faulkner; Travis Leithead; Erika Doyle Navara; Edward O'Connor; Silvia Pfeiffer. <a href="http://www.w3.org/TR/html5/"><cite>HTML5</cite></a>. 6 August 2013. W3C Candidate Recommendation. URL: <a href="http://www.w3.org/TR/html5/">http://www.w3.org/TR/html5/</a>
+</dd><dt id="bib-JSON-LD">[JSON-LD]</dt><dd rel="dcterms:references">Manu Sporny, Gregg Kellogg, Markus Lanthaler, Editors. <cite><a href="http://www.w3.org/TR/json-ld/">JSON-LD 1.0</a></cite>. 16 January 2014. W3C Recommendation. URL: <a href="http://www.w3.org/TR/json-ld/">http://www.w3.org/TR/json-ld/</a>
+</dd><dt id="bib-LINKED-DATA">[LINKED-DATA]</dt><dd rel="dcterms:references">Tim Berners-Lee. <cite><a href="http://www.w3.org/DesignIssues/LinkedData.html">Linked Data</a></cite>. Personal View, imperfect but published. URL: <a href="http://www.w3.org/DesignIssues/LinkedData.html">http://www.w3.org/DesignIssues/LinkedData.html</a>
+</dd><dt id="bib-OWL2-OVERVIEW">[OWL2-OVERVIEW]</dt><dd rel="dcterms:references">W3C OWL Working Group. <a href="http://www.w3.org/TR/owl2-overview/"><cite>OWL 2 Web Ontology Language Document Overview (Second Edition)</cite></a>. 11 December 2012. W3C Recommendation. URL: <a href="http://www.w3.org/TR/owl2-overview/">http://www.w3.org/TR/owl2-overview/</a>
+</dd><dt id="bib-RDF11-DATASETS">[RDF11-DATASETS]</dt><dd rel="dcterms:references">Antoine Zimmermann. <cite><a href="http://www.w3.org/TR/2014/NOTE-rdf11-datasets-20140225/">RDF 1.1: On Semantics of Datasets</a></cite>. W3C Working Group Note, 25 February 2014. The latest version is available at <a href="http://www.w3.org/TR/rdf11-datasets/">http://www.w3.org/TR/rdf11-datasets/</a>.
+</dd><dt id="bib-RDF11-MT">[RDF11-MT]</dt><dd rel="dcterms:references">Patrick J. Hayes, Peter F. Patel-Schneider. <cite><a href="http://www.w3.org/TR/2014/REC-rdf11-mt-20140225/">RDF 1.1 Semantics.</a></cite> W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-rdf11-mt-20140225/">http://www.w3.org/TR/2014/REC-rdf11-mt-20140225/</a>. The latest edition is available at <a href="http://www.w3.org/TR/rdf11-mt/">http://www.w3.org/TR/rdf11-mt/</a>
+</dd><dt id="bib-RDF11-NEW">[RDF11-NEW]</dt><dd rel="dcterms:references">David Wood. <cite><a href="http://www.w3.org/TR/2014/NOTE-rdf11-new-20140225/">What’s New in RDF 1.1</a></cite>. W3C Working Group Note, 25 February 2014. The latest version is available at <a href="http://www.w3.org/TR/rdf11-new/">http://www.w3.org/TR/rdf11-new/</a>.
+</dd><dt id="bib-RDF11-PRIMER">[RDF11-PRIMER]</dt><dd rel="dcterms:references">Guus Schreiber, Yves Raimond. <cite><a href="http://www.w3.org/TR/2014/NOTE-rdf11-primer-20140225/">RDF 1.1 Primer</a></cite>. W3C Working Group Note, 25 February 2014. The latest version is available at <a href="http://www.w3.org/TR/rdf11-primer/">http://www.w3.org/TR/rdf11-primer/</a>.
+</dd><dt id="bib-RDF11-SCHEMA">[RDF11-SCHEMA]</dt><dd rel="dcterms:references">Dan Brickley, R. V. Guha. <cite><a href="http://www.w3.org/TR/2014/REC-rdf-schema-20140225/">RDF Schema 1.1</a></cite>. W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-rdf-schema-20140225/">http://www.w3.org/TR/2014/REC-rdf-schema-20140225/</a>. The latest published version is available at <a href="http://www.w3.org/TR/rdf-schema/">http://www.w3.org/TR/rdf-schema/</a>.
+</dd><dt id="bib-RDF11-TESTCASES">[RDF11-TESTCASES]</dt><dd rel="dcterms:references">Gregg Kellogg, Markus Lanthaler. <cite><a href="http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/">RDF 1.1 Test Cases</a></cite>. W3C Working Group Note, 25 February 2014. The latest published version is available at <a href="http://www.w3.org/TR/rdf11-testcases/">http://www.w3.org/TR/rdf11-testcases/</a>.
+</dd><dt id="bib-RDF11-XML">[RDF11-XML]</dt><dd rel="dcterms:references">Fabien Gandon, Guus Schreiber. <cite><a href="http://www.w3.org/TR/2014/REC-rdf-syntax-grammar-20140225/">RDF 1.1 XML Syntax</a></cite>. W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-rdf-syntax-grammar-20140225/">http://www.w3.org/TR/2014/REC-rdf-syntax-grammar-20140225/</a>. The latest published version is available at <a href="http://www.w3.org/TR/rdf-syntax-grammar/">http://www.w3.org/TR/rdf-syntax-grammar/</a>.
+</dd><dt id="bib-RDFA-PRIMER">[RDFA-PRIMER]</dt><dd rel="dcterms:references">Ivan Herman; Ben Adida; Manu Sporny; Mark Birbeck. <a href="http://www.w3.org/TR/rdfa-primer/"><cite>RDFa 1.1 Primer - Second Edition</cite></a>. 22 August 2013. W3C Note. URL: <a href="http://www.w3.org/TR/rdfa-primer/">http://www.w3.org/TR/rdfa-primer/</a>
+</dd><dt id="bib-RFC3986">[RFC3986]</dt><dd rel="dcterms:references">T. Berners-Lee; R. Fielding; L. Masinter. <a href="http://www.ietf.org/rfc/rfc3986.txt"><cite>Uniform Resource Identifier (URI): Generic Syntax (RFC 3986)</cite></a>. January 2005. RFC. URL: <a href="http://www.ietf.org/rfc/rfc3986.txt">http://www.ietf.org/rfc/rfc3986.txt</a>
+</dd><dt id="bib-RFC5785">[RFC5785]</dt><dd rel="dcterms:references">Mark Nottingham; Eran Hammer-Lahav. <a href="http://www.rfc-editor.org/rfc/rfc5785.txt"><cite>Defining Well-Known Uniform Resource Identifiers (URIs) (RFC 5785)</cite></a>. April 2010. RFC. URL: <a href="http://www.rfc-editor.org/rfc/rfc5785.txt">http://www.rfc-editor.org/rfc/rfc5785.txt</a>
+</dd><dt id="bib-SPARQL11-OVERVIEW">[SPARQL11-OVERVIEW]</dt><dd rel="dcterms:references">The W3C SPARQL Working Group. <a href="http://www.w3.org/TR/sparql11-overview/"><cite>SPARQL 1.1 Overview</cite></a>. 21 March 2013. W3C Recommendation. URL: <a href="http://www.w3.org/TR/sparql11-overview/">http://www.w3.org/TR/sparql11-overview/</a>
+</dd><dt id="bib-SWBP-N-ARYRELATIONS">[SWBP-N-ARYRELATIONS]</dt><dd rel="dcterms:references">Natasha Noy; Alan Rector. <a href="http://www.w3.org/TR/swbp-n-aryRelations"><cite>Defining N-ary Relations on the Semantic Web</cite></a>. 12 April 2006. W3C Note. URL: <a href="http://www.w3.org/TR/swbp-n-aryRelations">http://www.w3.org/TR/swbp-n-aryRelations</a>
+</dd><dt id="bib-SWBP-XSCH-DATATYPES">[SWBP-XSCH-DATATYPES]</dt><dd rel="dcterms:references">Jeremy Carroll; Jeff Pan. <a href="http://www.w3.org/TR/swbp-xsch-datatypes"><cite>XML Schema Datatypes in RDF and OWL</cite></a>. 14 March 2006. W3C Note. URL: <a href="http://www.w3.org/TR/swbp-xsch-datatypes">http://www.w3.org/TR/swbp-xsch-datatypes</a>
+</dd><dt id="bib-TRIG">[TRIG]</dt><dd rel="dcterms:references">Gavin Carothers, Andy Seaborne. <cite><a href="http://www.w3.org/TR/2014/REC-trig-20140225/">TriG: RDF Dataset Language</a></cite>. W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-trig-20140225/">http://www.w3.org/TR/2014/REC-trig-20140225/</a>. The latest edition is available at <a href="http://www.w3.org/TR/trig/">http://www.w3.org/TR/trig/</a>
+</dd><dt id="bib-TURTLE">[TURTLE]</dt><dd rel="dcterms:references">Eric Prud'hommeaux, Gavin Carothers. <cite><a href="http://www.w3.org/TR/2014/REC-turtle-20140225/">RDF 1.1 Turtle: Terse RDF Triple Language.</a></cite> W3C Recommendation, 25 February 2014. URL: <a href="http://www.w3.org/TR/2014/REC-turtle-20140225/">http://www.w3.org/TR/2014/REC-turtle-20140225/</a>. The latest edition is available at <a href="http://www.w3.org/TR/turtle/">http://www.w3.org/TR/turtle/</a>
+</dd><dt id="bib-VOCAB-ORG">[VOCAB-ORG]</dt><dd rel="dcterms:references">Dave Reynolds. <a href="http://www.w3.org/TR/vocab-org/"><cite>The Organization Ontology</cite></a>. 16 January 2014. W3C Recommendation. URL: <a href="http://www.w3.org/TR/vocab-org/">http://www.w3.org/TR/vocab-org/</a>
+</dd><dt id="bib-WEBARCH">[WEBARCH]</dt><dd rel="dcterms:references">Ian Jacobs; Norman Walsh. <a href="http://www.w3.org/TR/webarch/"><cite>Architecture of the World Wide Web, Volume One</cite></a>. 15 December 2004. W3C Recommendation. URL: <a href="http://www.w3.org/TR/webarch/">http://www.w3.org/TR/webarch/</a>
+</dd><dt id="bib-XML-EXC-C14N">[XML-EXC-C14N]</dt><dd rel="dcterms:references">John Boyer; Donald Eastlake; Joseph Reagle. <a href="http://www.w3.org/TR/xml-exc-c14n"><cite>Exclusive XML Canonicalization Version 1.0</cite></a>. 18 July 2002. W3C Recommendation. URL: <a href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a>
+</dd><dt id="bib-XML-NAMES">[XML-NAMES]</dt><dd rel="dcterms:references">Tim Bray; Dave Hollander; Andrew Layman; Richard Tobin; Henry Thompson et al. <a href="http://www.w3.org/TR/xml-names"><cite>Namespaces in XML 1.0 (Third Edition)</cite></a>. 8 December 2009. W3C Recommendation. URL: <a href="http://www.w3.org/TR/xml-names">http://www.w3.org/TR/xml-names</a>
+</dd><dt id="bib-XML10">[XML10]</dt><dd rel="dcterms:references">Tim Bray; Jean Paoli; Michael Sperberg-McQueen; Eve Maler; François Yergeau et al. <a href="http://www.w3.org/TR/xml"><cite>Extensible Markup Language (XML) 1.0 (Fifth Edition)</cite></a>. 26 November 2008. W3C Recommendation. URL: <a href="http://www.w3.org/TR/xml">http://www.w3.org/TR/xml</a>
+</dd></dl></section></section></body></html>
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/REC-drafts/REC-rdf11-concepts-20140225/diff-20140109.html	Wed Feb 12 16:19:17 2014 +0100
@@ -0,0 +1,11616 @@
+<html lang="en" typeof="bibo:Document w3p:REC" about="" property="dcterms:language" content="en" prefix="bibo: http://purl.org/ontology/bibo/ w3p: http://www.w3.org/2001/02pd/rec54#" xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<meta charset="utf-8" />
+<title>RDF 1.1 Concepts and Abstract Syntax</title>
+
+<style type="text/css">
+/*<![CDATA[*/
+    figure { text-align: center; }
+    table td, table th { border: 1px solid #ddd; padding: 0.2em 0.5em; }
+    ol ol { list-style-type: lower-latin; }
+/*]]>*/
+</style>
+
+<style type="text/css">
+/*<![CDATA[*/
+    /* --- 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:  #ff4500;
+    }
+    /* --- 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 type="text/css">
+/*<![CDATA[*/
+/* --- ISSUES/NOTES --- */
+    div.issue-title, div.note-title {
+        padding-right:  1em;
+        min-width: 7.5em;
+        color: #b9ab2d;
+    }
+    div.issue-title { color: #e05252; }
+    div.note-title { color: #2b2; }
+    div.issue-title span, div.note-title span {
+        text-transform: uppercase;
+    }
+    div.note, div.issue {
+        margin-top: 1em;
+        margin-bottom: 1em;
+    }
+    .note > p:first-child, .issue > p:first-child { margin-top: 0 }
+    .issue, .note {
+        padding: .5em;
+        border-left-width: .5em;
+        border-left-style: solid;
+    }
+    div.issue, div.note {
+        padding: 1em 1.2em 0.5em;
+        margin: 1em 0;
+        position: relative;
+        clear: both;
+    }
+    span.note, span.issue { padding: .1em .5em .15em; }
+    .issue {
+        border-color: #e05252;
+        background: #fbe9e9;
+    }
+    .note {
+        border-color: #52e052;
+        background: #e9fbe9;
+    }
+/*]]>*/
+</style>
+<link rel="stylesheet" href="https://www.w3.org/StyleSheets/TR/W3C-REC" type="text/css" /><!--[if lt IE 9]><script src='https://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]-->
+<style type='text/css'>
+.diff-old-a {
+  font-size: smaller;
+  color: red;
+}
+
+.diff-new { background-color: yellow; }
+.diff-chg { background-color: lime; }
+.diff-new:before,
+.diff-new:after
+    { content: "\2191" }
+.diff-chg:before, .diff-chg:after
+    { content: "\2195" }
+.diff-old { text-decoration: line-through; background-color: #FBB; }
+.diff-old:before,
+.diff-old:after
+    { content: "\2193" }
+:focus { border: thin red solid}
+</style>
+</head>
+<body class="h-entry" style="" role="document" id="respecDocument">
+<div class="head" role="contentinfo" id="respecHeader">
+<p>
+<a 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">
+RDF
+1.1
+Concepts
+and
+Abstract
+Syntax
+</h1>
+<h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-02-24T23:00:00.000Z" id="w3c-recommendation-25-february-2014">
+<abbr title="World Wide Web Consortium">
+W3C
+</abbr>
+<del class="diff-old">Proposed
+</del>
+Recommendation
+<del class="diff-old">09
+January
+</del>
+<time class="dt-published" datetime="2014-02-25">
+<ins class="diff-chg">25
+February
+</ins>
+2014
+</time>
+</h2>
+<dl>
+<dt>
+This
+version:
+</dt>
+<dd>
+<del class="diff-old">http://www.w3.org/TR/2014/PR-rdf11-concepts-20140109/
+</del>
+<a class="u-url" href="http://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/">
+<ins class="diff-chg">http://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/
+</ins>
+</a>
+</dd>
+<dt>
+Latest
+published
+version:
+</dt>
+<dd>
+<a href="http://www.w3.org/TR/rdf11-concepts/">
+http://www.w3.org/TR/rdf11-concepts/
+</a>
+</dd>
+<dt>
+<del class="diff-old">Latest
+editor's
+draft:
+https://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html
+</del>
+Implementation
+report:
+</dt>
+<dd>
+<del class="diff-old">https://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/reports/index.html
+</del>
+<a href="http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/">
+<ins class="diff-chg">http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/
+</ins>
+</a>
+</dd>
+<dt>
+Previous
+version:
+</dt>
+<dd>
+<del class="diff-old">http://www.w3.org/TR/2013/CR-rdf11-concepts-20131105/
+</del>
+<a rel="dcterms:replaces" href="http://www.w3.org/TR/2014/PR-rdf11-concepts-20140109/">
+<ins class="diff-chg">http://www.w3.org/TR/2014/PR-rdf11-concepts-20140109/
+</ins>
+</a>
+</dd>
+<dt>
+<del class="diff-old">Latest
+</del>
+<ins class="diff-chg">Previous
+</ins>
+Recommendation:
+</dt>
+<dd>
+<a rel="dcterms:replaces" href="http://www.w3.org/TR/rdf-concepts">
+http://www.w3.org/TR/rdf-concepts
+</a>
+</dd>
+<dt>
+Editors:
+</dt>
+<dd class="p-author h-card vcard" rel="bibo:editor" inlist="">
+<span typeof="foaf:Person">
+<a class="u-url url p-name fn" rel="foaf:homepage" property="foaf:name" content="Richard Cyganiak" href="http://richard.cyganiak.de/">
+Richard
+Cyganiak
+</a>,
+<a rel="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.deri.ie/">
+DERI,
+NUI
+Galway
+</a>
+</span>
+</dd>
+<dd class="p-author h-card vcard" rel="bibo:editor" inlist="">
+<span typeof="foaf:Person">
+<a class="u-url url p-name fn" rel="foaf:homepage" property="foaf:name" content="David Wood" href="http://about.me/david_wood">
+David
+Wood
+</a>,
+<a rel="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://3roundstones.com/">
+3
+Round
+Stones
+</a>
+</span>
+</dd>
+<dd class="p-author h-card vcard" rel="bibo:editor" inlist="">
+<span typeof="foaf:Person">
+<a class="u-url url p-name fn" rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">
+Markus
+Lanthaler
+</a>,
+<a rel="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.tugraz.at/">
+Graz
+University
+of
+Technology
+</a>
+</span>
+</dd>
+<dt>
+Previous
+Editors:
+</dt>
+<dd>
+Graham
+Klyne
+</dd>
+<dd>
+Jeremy
+J.
+Carroll
+</dd>
+<dd>
+Brian
+McBride
+</dd>
+</dl>
+<p>
+<ins class="diff-new">Please
+check
+the
+</ins><a href="http://www.w3.org/2014/rdf1.1-errata"><strong><ins class="diff-new">
+errata
+</ins></strong></a><ins class="diff-new">
+for
+any
+errors
+or
+issues
+reported
+since
+publication.
+</ins></p><p>
+This
+document
+is
+also
+available
+in
+this
+non-normative
+format:
+<a rel="alternate" href="diff-20140109.html">
+diff
+to
+previous
+version
+</a>
+</p>
+<p>
+<ins class="diff-new">The
+English
+version
+of
+this
+specification
+is
+the
+only
+normative
+version.
+Non-normative
+</ins><a href="http://www.w3.org/Consortium/Translation/"><ins class="diff-new">
+translations
+</ins></a><ins class="diff-new">
+may
+also
+be
+available.
+</ins>
+</p>
+<p class="copyright">
+<a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">
+Copyright
+</a>

+2004-2014
+<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>
+),
+All
+Rights
+Reserved.
+<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 href="http://www.w3.org/Consortium/Legal/copyright-documents">
+document
+use
+</a>
+rules
+apply.
+</p>
+<hr />
+</div>
+<section id="abstract" class="introductory" property="dcterms:abstract" datatype="" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h2 aria-level="1" role="heading" id="h2_abstract">
+Abstract
+</h2>
+<p>
+The
+Resource
+Description
+Framework
+(RDF)
+is
+a
+framework
+for
+representing
+information
+in
+the
+Web.
+This
+document
+defines
+an
+abstract
+syntax
+(a
+data
+model)
+which
+serves
+to
+link
+all
+RDF-based
+languages
+and
+specifications.
+The
+abstract
+syntax
+has
+two
+key
+data
+structures:
+RDF
+graphs
+are
+sets
+of
+subject-predicate-object
+triples,
+where
+the
+elements
+may
+be
+IRIs,
+blank
+nodes,
+or
+datatyped
+literals.
+They
+are
+used
+to
+express
+descriptions
+of
+resources.
+RDF
+datasets
+are
+used
+to
+organize
+collections
+of
+RDF
+graphs,
+and
+comprise
+a
+default
+graph
+and
+zero
+or
+more
+named
+graphs.
+<del class="diff-old">RDF 1.1
+</del>
+<ins class="diff-chg">RDF&#160;1.1
+</ins>
+Concepts
+and
+Abstract
+Syntax
+also
+introduces
+key
+concepts
+and
+terminology,
+and
+discusses
+datatyping
+and
+the
+handling
+of
+fragment
+identifiers
+in
+IRIs
+within
+RDF
+graphs.
+</p>
+</section>
+<section id="sotd" class="introductory" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h2 aria-level="1" role="heading" id="h2_sotd">
+Status
+of
+This
+Document
+</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>
+This
+document
+is
+<del class="diff-old">a
+</del>
+part
+of
+the
+RDF
+1.1
+document
+suite.
+<del class="diff-old">The
+</del>
+<ins class="diff-chg">It
+is
+the
+central
+</ins>
+RDF
+<del class="diff-old">Working
+Group
+welcomes
+comments
+</del>
+<ins class="diff-chg">1.1
+specification
+</ins>
+and
+<del class="diff-old">reports
+of
+implementations
+</del>
+<ins class="diff-chg">defines
+the
+core
+RDF
+concepts.
+A
+new
+concept
+</ins>
+in
+<del class="diff-old">general,
+but
+given
+</del>
+<ins class="diff-chg">RDF
+1.1
+is
+</ins>
+the
+<del class="diff-old">nature
+</del>
+<ins class="diff-chg">notion
+</ins>
+of
+<del class="diff-old">this
+document
+(as
+a
+conceptual
+overview),
+the
+group
+is
+not
+expecting
+</del>
+<ins class="diff-chg">an
+RDF
+dataset
+to
+represent
+multiple
+graphs.
+There
+have
+been
+no
+changes
+</ins>
+to
+<del class="diff-old">track
+implementations
+of
+</del>
+this
+document
+<del class="diff-old">on
+</del>
+<ins class="diff-chg">since
+</ins>
+its
+<del class="diff-old">own.
+</del>
+<ins class="diff-chg">publication
+as
+Proposed
+Recommendation.
+</ins>
+</p>
+<p>
+This
+document
+was
+published
+by
+the
+<a href="http://www.w3.org/2011/rdf-wg/">
+RDF
+Working
+Group
+</a>
+as
+a
+<del class="diff-old">Proposed
+</del>
+Recommendation.
+<del class="diff-old">This
+document
+is
+intended
+to
+become
+a
+W3C
+Recommendation.
+The
+W3C
+Membership
+and
+other
+interested
+parties
+are
+invited
+</del>
+<ins class="diff-chg">If
+you
+wish
+</ins>
+to
+<del class="diff-old">review
+the
+document
+and
+send
+</del>
+<ins class="diff-chg">make
+</ins>
+comments
+<ins class="diff-new">regarding
+this
+document,
+please
+send
+them
+</ins>
+to
+<a href="mailto:[email protected]">
[email protected]
+</a>
+(
+<a href="mailto:[email protected]?subject=subscribe">
+subscribe
+</a>,
+<a href="http://lists.w3.org/Archives/Public/public-rdf-comments/">
+archives
+</a>
+<del class="diff-old">)
+through
+09
+February
+2014.
+Advisory
+Committee
+Representatives
+should
+consult
+their
+WBS
+questionnaires
+.
+Note
+that
+substantive
+technical
+</del>
+<ins class="diff-chg">).
+All
+</ins>
+comments
+<del class="diff-old">were
+expected
+during
+the
+Last
+Call
+review
+period
+that
+ended
+06
+September
+2013.
+</del>
+<ins class="diff-chg">are
+welcome.
+</ins>
+</p>
+<p>
+Please
+see
+the
+Working
+Group's
+<a href="http://www.w3.org/TR/2014/NOTE-rdf11-testcases-20140225/">
+implementation
+report
+</a>.
+</p>
+<p>
+<del class="diff-old">Publication
+as
+a
+Proposed
+Recommendation
+does
+not
+imply
+endorsement
+</del>
+<ins class="diff-chg">This
+document
+has
+been
+reviewed
+by
+</ins><abbr title="World Wide Web Consortium"><ins class="diff-chg">
+W3C
+</ins></abbr><ins class="diff-chg">
+Members,
+by
+software
+developers,
+and
+by
+other
+</ins><abbr title="World Wide Web Consortium"><ins class="diff-chg">
+W3C
+</ins></abbr><ins class="diff-chg">
+groups
+and
+interested
+parties,
+and
+is
+endorsed
+</ins>
+by
+the
+<ins class="diff-new">Director
+as
+a
+</ins>
+<abbr title="World Wide Web Consortium">
+W3C
+</abbr>
+<del class="diff-old">Membership.
+This
+</del>
+<ins class="diff-chg">Recommendation.
+It
+</ins>
+is
+a
+<del class="diff-old">draft
+</del>
+<ins class="diff-chg">stable
+</ins>
+document
+and
+may
+be
+<del class="diff-old">updated,
+replaced
+</del>
+<ins class="diff-chg">used
+as
+reference
+material
+</ins>
+or
+<del class="diff-old">obsoleted
+by
+other
+documents
+at
+any
+time.
+It
+</del>
+<ins class="diff-chg">cited
+from
+another
+document.
+</ins><abbr title="World Wide Web Consortium"><ins class="diff-chg">
+W3C
+</ins></abbr><ins class="diff-chg">
+'s
+role
+in
+making
+the
+Recommendation
+</ins>
+is
+<del class="diff-old">inappropriate
+</del>
+to
+<del class="diff-old">cite
+this
+document
+as
+other
+than
+work
+in
+progress.
+</del>
+<ins class="diff-chg">draw
+attention
+to
+the
+specification
+and
+to
+promote
+its
+widespread
+deployment.
+This
+enhances
+the
+functionality
+and
+interoperability
+of
+the
+Web.
+</ins>
+</p>
+<p>
+This
+document
+was
+produced
+by
+a
+group
+operating
+under
+the
+<a id="sotd_patent" about="" rel="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/46168/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>
+</section>
+<section id="toc">
+<h2 class="introductory" aria-level="1" role="heading" id="h2_toc">
+Table
+of
+Contents
+</h2>
+<ul class="toc" role="directory" id="respecContents">
+<li class="tocline">
+<a href="#section-Introduction" class="tocxref">
+<span class="secno">
+1.
+</span>
+Introduction
+</a>
+<ul class="toc">
+<li class="tocline">
+<a href="#data-model" class="tocxref">
+<span class="secno">
+1.1
+</span>
+Graph-based
+Data
+Model
+</a>
+</li>
+<li class="tocline">
+<a href="#resources-and-statements" class="tocxref">
+<span class="secno">
+1.2
+</span>
+Resources
+and
+Statements
+</a>
+</li>
+<li class="tocline">
+<a href="#referents" class="tocxref">
+<span class="secno">
+1.3
+</span>
+The
+Referent
+of
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+</li>
+<li class="tocline">
+<a href="#vocabularies" class="tocxref">
+<span class="secno">
+1.4
+</span>
+RDF
+Vocabularies
+and
+Namespace
+IRIs
+</a>
+</li>
+<li class="tocline">
+<a href="#change-over-time" class="tocxref">
+<span class="secno">
+1.5
+</span>
+RDF
+and
+Change
+over
+Time
+</a>
+</li>
+<li class="tocline">
+<a href="#managing-graphs" class="tocxref">
+<span class="secno">
+1.6
+</span>
+Working
+with
+Multiple
+RDF
+Graphs
+</a>
+</li>
+<li class="tocline">
+<a href="#entailment" class="tocxref">
+<span class="secno">
+1.7
+</span>
+Equivalence,
+Entailment
+and
+Inconsistency
+</a>
+</li>
+<li class="tocline">
+<a href="#rdf-documents" class="tocxref">
+<span class="secno">
+1.8
+</span>
+RDF
+Documents
+and
+Syntaxes
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a href="#conformance" class="tocxref">
+<span class="secno">
+2.
+</span>
+Conformance
+</a>
+</li>
+<li class="tocline">
+<a href="#section-rdf-graph" class="tocxref">
+<span class="secno">
+3.
+</span>
+RDF
+Graphs
+</a>
+<ul class="toc">
+<li class="tocline">
+<a href="#section-triples" class="tocxref">
+<span class="secno">
+3.1
+</span>
+Triples
+</a>
+</li>
+<li class="tocline">
+<a href="#section-IRIs" class="tocxref">
+<span class="secno">
+3.2
+</span>
+IRIs
+</a>
+</li>
+<li class="tocline">
+<a href="#section-Graph-Literal" class="tocxref">
+<span class="secno">
+3.3
+</span>
+Literals
+</a>
+</li>
+<li class="tocline">
+<a href="#section-blank-nodes" class="tocxref">
+<span class="secno">
+3.4
+</span>
+Blank
+Nodes
+</a>
+</li>
+<li class="tocline">
+<a href="#section-skolemization" class="tocxref">
+<span class="secno">
+3.5
+</span>
+Replacing
+Blank
+Nodes
+with
+IRIs
+</a>
+</li>
+<li class="tocline">
+<a href="#graph-isomorphism" class="tocxref">
+<span class="secno">
+3.6
+</span>
+Graph
+Comparison
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a href="#section-dataset" class="tocxref">
+<span class="secno">
+4.
+</span>
+RDF
+Datasets
+</a>
+<ul class="toc">
+<li class="tocline">
+<a href="#section-dataset-isomorphism" class="tocxref">
+<span class="secno">
+4.1
+</span>
+RDF
+Dataset
+Comparison
+</a>
+</li>
+<li class="tocline">
+<a href="#section-dataset-conneg" class="tocxref">
+<span class="secno">
+4.2
+</span>
+Content
+Negotiation
+of
+RDF
+Datasets
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a href="#section-Datatypes" class="tocxref">
+<span class="secno">
+5.
+</span>
+Datatypes
+</a>
+<ul class="toc">
+<li class="tocline">
+<a href="#xsd-datatypes" class="tocxref">
+<span class="secno">
+5.1
+</span>
+The
+XML
+Schema
+Built-in
+Datatypes
+</a>
+</li>
+<li class="tocline">
+<a href="#section-html" class="tocxref">
+<span class="secno">
+5.2
+</span>
+The
+<code>
+rdf:HTML
+</code>
+Datatype
+</a>
+</li>
+<li class="tocline">
+<a href="#section-XMLLiteral" class="tocxref">
+<span class="secno">
+5.3
+</span>
+The
+<code>
+rdf:XMLLiteral
+</code>
+Datatype
+</a>
+</li>
+<li class="tocline">
+<a href="#datatype-iris" class="tocxref">
+<span class="secno">
+5.4
+</span>
+Datatype
+IRIs
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a href="#section-fragID" class="tocxref">
+<span class="secno">
+6.
+</span>
+Fragment
+Identifiers
+</a>
+</li>
+<li class="tocline">
+<a href="#section-generalized-rdf" class="tocxref">
+<span class="secno">
+7.
+</span>
+Generalized
+RDF
+Triples,
+Graphs,
+and
+Datasets
+</a>
+</li>
+<li class="tocline">
+<a href="#section-Acknowledgments" class="tocxref">
+<span class="secno">
+8.
+</span>
+Acknowledgments
+</a>
+</li>
+<li class="tocline">
+<a href="#changes" class="tocxref">
+<span class="secno">
+A.
+</span>
+Changes
+between
+RDF
+1.0
+and
+RDF
+1.1
+</a>
+</li>
+<del class="diff-old">B.
+Changes
+since
+the
+5
+November
+2013
+Candidate
+Recommendation
+</del>
+<li class="tocline">
+<a href="#references" class="tocxref">
+<span class="secno">
+<del class="diff-old">C.
+</del>
+<ins class="diff-chg">B.
+</ins>
+</span>
+References
+</a>
+<ul class="toc">
+<li class="tocline">
+<a href="#normative-references" class="tocxref">
+<span class="secno">
+<del class="diff-old">C.1
+</del>
+<ins class="diff-chg">B.1
+</ins>
+</span>
+Normative
+references
+</a>
+</li>
+<li class="tocline">
+<a href="#informative-references" class="tocxref">
+<span class="secno">
+<del class="diff-old">C.2
+</del>
+<ins class="diff-chg">B.2
+</ins>
+</span>
+Informative
+references
+</a>
+</li>
+</ul>
+</li>
+</ul>
+</section>
+<section id="section-Introduction" class="informative" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h2 aria-level="1" role="heading" id="h2_section-Introduction">
+<span class="secno">
+1.
+</span>
+Introduction
+</h2>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+The
+<em>
+Resource
+Description
+Framework
+</em>
+(RDF)
+is
+a
+framework
+for
+representing
+information
+in
+the
+Web.
+</p>
+<p>
+This
+document
+defines
+an
+abstract
+syntax
+(a
+data
+model)
+which
+serves
+to
+link
+all
+RDF-based
+languages
+and
+specifications,
+including:
+</p>
+<ul>
+<li>
+the
+<a href="http://www.w3.org/TR/rdf11-mt/">
+formal
+model-theoretic
+semantics
+for
+RDF
+and
+RDFS
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-MT">
+RDF11-MT
+</a>
+</cite>
+<del class="diff-old">].
+</del>
+<ins class="diff-chg">]
+</ins>
+</li>
+<li>
+serialization
+syntaxes
+for
+storing
+and
+exchanging
+RDF
+<del class="diff-old">(e.g.,
+</del>
+<ins class="diff-chg">such
+as
+</ins>
+<a href="http://www.w3.org/TR/turtle/">
+Turtle
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-TURTLE">
+TURTLE
+</a>
+</cite>
+]
+and
+<a href="http://www.w3.org/TR/json-ld/">
+JSON-LD
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-JSON-LD">
+JSON-LD
+</a>
+</cite>
+<del class="diff-old">]),
+</del>
+<ins class="diff-chg">]
+</ins>
+</li>
+<li>
+the
+<a href="http://www.w3.org/TR/rdf-sparql-query/">
+SPARQL
+Query
+Language
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-SPARQL11-OVERVIEW">
+SPARQL11-OVERVIEW
+</a>
+</cite>
+<del class="diff-old">],
+</del>
+<ins class="diff-chg">]
+</ins>
+</li>
+<li>
+the
+<a href="http://www.w3.org/TR/rdf-schema/">
+RDF
+Vocabulary
+Description
+Language
+</a>
+(RDFS)
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-SCHEMA">
+RDF11-SCHEMA
+</a>
+</cite>
+<del class="diff-old">],
+</del>
+<ins class="diff-chg">]
+</ins>
+</li>
+</ul>
+<section id="data-model" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_data-model">
+<span class="secno">
+1.1
+</span>
+Graph-based
+Data
+Model
+</h3>
+<p>
+The
+core
+structure
+of
+the
+abstract
+syntax
+is
+a
+set
+of
+<a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">
+triples
+</a>,
+each
+consisting
+of
+a
+<a href="#dfn-subject" class="internalDFN">
+subject
+</a>,
+a
+<a href="#dfn-predicate" class="internalDFN">
+predicate
+</a>
+and
+an
+<a href="#dfn-object" class="internalDFN">
+object
+</a>.
+A
+set
+of
+such
+triples
+is
+called
+an
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>.
+An
+RDF
+graph
+can
+be
+visualized
+as
+a
+node
+and
+directed-arc
+diagram,
+in
+which
+each
+triple
+is
+represented
+as
+a
+node-arc-node
+link.
+</p>
+<figure id="fig-an-rdf-graph-with-two-nodes-subject-and-object-and-a-triple-connecting-them-predicate">
+<a href="rdf-graph.svg">
+<img src="rdf-graph.svg" alt="An RDF graph with two nodes (Subject and Object) and a triple connecting them (Predicate)" />
+</a>
+<figcaption>
+Fig.
+<span class="figno">
+1
+</span>
+<span class="fig-title">
+An
+RDF
+graph
+with
+two
+nodes
+(Subject
+and
+Object)
+and
+a
+triple
+connecting
+them
+(Predicate)
+</span>
+</figcaption>
+</figure>
+<p>
+There
+can
+be
+three
+kinds
+of
+<a title="node" href="#dfn-node" class="internalDFN">
+nodes
+</a>
+in
+an
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>:
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>,
+<a title="literal" href="#dfn-literal" class="internalDFN">
+literals
+</a>,
+and
+<a title="blank node" href="#dfn-blank-node" class="internalDFN">
+blank
+nodes
+</a>.
+</p>
+</section>
+<section id="resources-and-statements" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_resources-and-statements">
+<span class="secno">
+1.2
+</span>
+Resources
+and
+Statements
+</h3>
+<p>
+Any
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+<a href="#dfn-literal" class="internalDFN">
+literal
+</a>
+<dfn title="denote" id="dfn-denote">
+denotes
+</dfn>
+something
+in
+the
+world
+(the
+<del class="diff-old">&quot;universe
+</del>
+<ins class="diff-chg">"universe
+</ins>
+of
+<del class="diff-old">discourse&quot;).
+</del>
+<ins class="diff-chg">discourse").
+</ins>
+These
+things
+are
+called
+<dfn title="resource" id="dfn-resource">
+resources
+</dfn>.
+Anything
+can
+be
+a
+resource,
+including
+physical
+things,
+documents,
+abstract
+concepts,
+numbers
+and
+strings;
+the
+term
+is
+synonymous
+with
+<del class="diff-old">&quot;entity&quot;
+</del>
+<ins class="diff-chg">"entity"
+</ins>
+as
+it
+is
+used
+in
+the
+RDF
+Semantics
+specification
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-MT">
+RDF11-MT
+</a>
+</cite>
+].
+The
+resource
+denoted
+by
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+is
+called
+its
+<a href="#dfn-referent" class="internalDFN">
+referent
+</a>,
+and
+the
+resource
+denoted
+by
+a
+literal
+is
+called
+its
+<a title="literal value" href="#dfn-literal-value" class="internalDFN">
+literal
+value
+</a>.
+Literals
+have
+<a title="datatype" href="#dfn-datatype" class= "internalDFN">
+datatypes
+</a>
+that
+define
+the
+range
+of
+possible
+values,
+such
+as
+strings,
+numbers,
+and
+dates.
+Special
+kind
+of
+literals,
+<a title="language-tagged string" href="#dfn-language-tagged-string" class="internalDFN">
+language-tagged
+strings
+</a>,
+denote
+plain-text
+strings
+in
+a
+natural
+language.
+</p>
+<p>
+Asserting
+an
+<a href="#dfn-rdf-triple" class="internalDFN">
+RDF
+triple
+</a>
+says
+that
+<em>
+some
+relationship,
+indicated
+by
+the
+<a href="#dfn-predicate" class="internalDFN">
+predicate
+</a>,
+holds
+between
+the
+<a title="resource" href="#dfn-resource" class="internalDFN">
+resources
+</a>
+<a title="denote" href="#dfn-denote" class="internalDFN">
+denoted
+</a>
+by
+the
+<a href="#dfn-subject" class="internalDFN">
+subject
+</a>
+and
+<a href="#dfn-object" class="internalDFN">
+object
+</a>
+</em>.
+This
+statement
+corresponding
+to
+an
+RDF
+triple
+is
+known
+as
+an
+<dfn id="dfn-rdf-statement">
+RDF
+statement
+</dfn>.
+The
+predicate
+itself
+is
+an
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+and
+denotes
+a
+<dfn id="dfn-property">
+property
+</dfn>,
+that
+is,
+a
+<a href="#dfn-resource" class="internalDFN">
+resource
+</a>
+that
+can
+be
+thought
+of
+as
+a
+binary
+relation.
+(Relations
+that
+involve
+more
+than
+two
+entities
+can
+only
+be
+<a href= "http://www.w3.org/TR/swbp-n-aryRelations/">
+indirectly
+expressed
+in
+RDF
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-SWBP-N-ARYRELATIONS">
+SWBP-N-ARYRELATIONS
+</a>
+</cite>
+].)
+</p>
+<p>
+Unlike
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>
+and
+<a title="literal" href="#dfn-literal" class="internalDFN">
+literals
+</a>,
+<a title="blank node" href="#dfn-blank-node" class="internalDFN">
+blank
+nodes
+</a>
+do
+not
+identify
+specific
+<a title="resource" href="#dfn-resource" class="internalDFN">
+resources
+</a>.
+<a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">
+Statements
+</a>
+involving
+blank
+nodes
+say
+that
+something
+with
+the
+given
+relationships
+exists,
+without
+explicitly
+naming
+it.
+</p>
+</section>
+<section id="referents" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_referents">
+<span class="secno">
+1.3
+</span>
+The
+Referent
+of
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</h3>
+<p>
+The
+<a href="#dfn-resource" class="internalDFN">
+resource
+</a>
+<a title="denote" href="#dfn-denote" class="internalDFN">
+denoted
+</a>
+by
+an
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+also
+called
+its
+<dfn id="dfn-referent">
+referent
+</dfn>.
+For
+some
+IRIs
+with
+particular
+meanings,
+such
+as
+those
+identifying
+XSD
+datatypes,
+the
+referent
+is
+fixed
+by
+this
+specification.
+For
+all
+other
+IRIs,
+what
+exactly
+is
+denoted
+by
+any
+given
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+is
+not
+defined
+by
+this
+specification.
+Other
+specifications
+may
+fix
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+referents,
+or
+apply
+other
+constraints
+on
+what
+may
+be
+the
+referent
+of
+any
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>.
+</p>
+<p>
+Guidelines
+for
+determining
+the
+<a href="#dfn-referent" class="internalDFN">
+referent
+</a>
+of
+an
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+are
+provided
+in
+other
+documents,
+like
+<em>
+<a href="http://www.w3.org/TR/webarch/">
+Architecture
+of
+the
+World
+Wide
+Web,
+Volume
+One
+</a>
+</em>
+[
+<cite>
+<a class="bibref" href="#bib-WEBARCH">
+WEBARCH
+</a>
+</cite>
+]
+and
+<em>
+<a href="http://www.w3.org/TR/cooluris/">
+Cool
+URIs
+for
+the
+Semantic
+Web
+</a>
+</em>
+[
+<cite>
+<a class="bibref" href="#bib-COOLURIS">
+COOLURIS
+</a>
+</cite>
+].
+A
+very
+brief,
+informal,
+and
+partial
+account
+follows:
+</p>
+<ul>
+<li>
+By
+design,
+IRIs
+have
+global
+scope.
+Thus,
+two
+different
+appearances
+of
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+<a href="#dfn-denote" class="internalDFN">
+denote
+</a>
+the
+same
+<a href="#dfn-resource" class="internalDFN">
+resource
+</a>.
+Violating
+this
+principle
+constitutes
+an
+<a href="http://www.w3.org/TR/webarch/#URI-collision">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+collision
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-WEBARCH">
+WEBARCH
+</a>
+</cite>
+].
+</li>
+<li>
+By
+social
+convention,
+the
+<a href="http://www.w3.org/TR/webarch/#uri-ownership">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+owner
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-WEBARCH">
+WEBARCH
+</a>
+</cite>
+]
+gets
+to
+say
+what
+the
+intended
+(or
+usual)
+referent
+of
+an
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is.
+Applications
+and
+users
+need
+not
+abide
+by
+this
+intended
+denotation,
+but
+there
+may
+be
+a
+loss
+of
+interoperability
+with
+other
+applications
+and
+users
+if
+they
+do
+not
+do
+so.
+</li>
+<li>
+The
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+owner
+can
+establish
+the
+intended
+<a href="#dfn-referent" class="internalDFN">
+referent
+</a>
+by
+means
+of
+a
+specification
+or
+other
+document
+that
+explains
+what
+is
+denoted.
+For
+example,
+the
+<a href="http://www.w3.org/TR/vocab-org/">
+Organization
+Ontology
+document
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-VOCAB-ORG">
+VOCAB-ORG
+</a>
+</cite>
+]
+specifies
+the
+intended
+referents
+of
+various
+IRIs
+that
+start
+with
+<code>
+http://www.w3.org/ns/org#
+</code>.
+</li>
+<li>
+A
+good
+way
+of
+communicating
+the
+intended
+referent
+is
+to
+set
+up
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+so
+that
+it
+<a href="http://www.w3.org/TR/webarch/#uri-dereference">
+dereferences
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-WEBARCH">
+WEBARCH
+</a>
+</cite>
+]
+to
+such
+a
+document.
+</li>
+<li>
+Such
+a
+document
+can,
+in
+fact,
+be
+an
+<a href="#dfn-rdf-document" class="internalDFN">
+RDF
+document
+</a>
+that
+describes
+the
+denoted
+resource
+by
+means
+of
+<a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">
+RDF
+statements
+</a>.
+</li>
+</ul>
+<p>
+Perhaps
+the
+most
+important
+characteristic
+of
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>
+in
+web
+architecture
+is
+that
+they
+can
+be
+<a href="http://www.w3.org/TR/webarch/#uri-dereference">
+dereferenced
+</a>,
+and
+hence
+serve
+as
+starting
+points
+for
+interactions
+with
+a
+remote
+server.
+This
+specification
+is
+not
+concerned
+with
+such
+interactions.
+It
+does
+not
+define
+an
+interaction
+model.
+It
+only
+treats
+IRIs
+as
+globally
+unique
+identifiers
+in
+a
+graph
+data
+model
+that
+describes
+resources.
+However,
+those
+interactions
+are
+critical
+to
+the
+concept
+of
+<em>
+<a href="http://www.w3.org/DesignIssues/LinkedData.html">
+Linked
+Data
+</a>
+</em>
+[
+<cite>
+<a class="bibref" href="#bib-LINKED-DATA">
+LINKED-DATA
+</a>
+</cite>
+],
+which
+makes
+use
+of
+the
+RDF
+data
+model
+and
+serialization
+formats.
+</p>
+</section>
+<section id="vocabularies" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_vocabularies">
+<span class="secno">
+1.4
+</span>
+RDF
+Vocabularies
+and
+Namespace
+IRIs
+</h3>
+<p>
+An
+<dfn id="dfn-rdf-vocabulary">
+RDF
+vocabulary
+</dfn>
+is
+a
+collection
+of
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>
+intended
+for
+use
+in
+<a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graphs
+</a>.
+For
+example,
+the
+IRIs
+documented
+in
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-SCHEMA">
+RDF11-SCHEMA
+</a>
+</cite>
+]
+are
+the
+RDF
+Schema
+vocabulary.
+RDF
+Schema
+can
+itself
+be
+used
+to
+define
+and
+document
+additional
+RDF
+vocabularies.
+Some
+such
+vocabularies
+are
+mentioned
+in
+the
+Primer
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-PRIMER">
+RDF11-PRIMER
+</a>
+</cite>
+].
+</p>
+<p>
+The
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>
+in
+an
+<a href="#dfn-rdf-vocabulary" class="internalDFN">
+RDF
+vocabulary
+</a>
+often
+begin
+with
+a
+common
+substring
+known
+as
+a
+<dfn id="dfn-namespace-iri">
+namespace
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>.
+Some
+namespace
+IRIs
+are
+associated
+by
+convention
+with
+a
+short
+name
+known
+as
+a
+<dfn id="dfn-namespace-prefix">
+namespace
+prefix
+</dfn>.
+Some
+examples:
+</p>
+<table class="simple">
+<caption>
+Some
+example
+namespace
+prefixes
+and
+IRIs
+</caption>
+<tbody>
+<tr>
+<th>
+Namespace
+prefix
+</th>
+<th>
+Namespace
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</th>
+<th>
+RDF
+vocabulary
+</th>
+</tr>
+<tr>
+<td>
+rdf
+</td>
+<td>
+<a href="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+<code>
+http://www.w3.org/1999/02/22-rdf-syntax-ns#
+</code>
+</a>
+</td>
+<td>
+The
+RDF
+built-in
+vocabulary
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-SCHEMA">
+RDF11-SCHEMA
+</a>
+</cite>
+]
+</td>
+</tr>
+<tr>
+<td>
+rdfs
+</td>
+<td>
+<a href="http://www.w3.org/2000/01/rdf-schema#">
+<code>
+http://www.w3.org/2000/01/rdf-schema#
+</code>
+</a>
+</td>
+<td>
+The
+RDF
+Schema
+vocabulary
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-SCHEMA">
+RDF11-SCHEMA
+</a>
+</cite>
+]
+</td>
+</tr>
+<tr>
+<td>
+xsd
+</td>
+<td>
+<a href="http://www.w3.org/2001/XMLSchema#">
+<code>
+http://www.w3.org/2001/XMLSchema#
+</code>
+</a>
+</td>
+<td>
+The
+<a href="#dfn-rdf-compatible-xsd-types" class="internalDFN">
+RDF-compatible
+XSD
+types
+</a>
+</td>
+</tr>
+</tbody>
+</table>
+<p>
+In
+some
+serialization
+formats
+it
+is
+common
+to
+abbreviate
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>
+that
+start
+with
+<a title="namespace IRI" href="#dfn-namespace-iri" class="internalDFN">
+namespace
+IRIs
+</a>
+by
+using
+a
+<a href="#dfn-namespace-prefix" class="internalDFN">
+namespace
+prefix
+</a>
+in
+order
+to
+assist
+readability.
+For
+example,
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+<code>
+http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral
+</code>
+would
+be
+abbreviated
+as
+<code>
+rdf:XMLLiteral
+</code>.
+Note
+however
+that
+these
+abbreviations
+are
+<em>
+not
+</em>
+valid
+IRIs,
+and
+must
+not
+be
+used
+in
+contexts
+where
+IRIs
+are
+expected.
+Namespace
+IRIs
+and
+namespace
+prefixes
+are
+<em>
+not
+</em>
+a
+formal
+part
+of
+the
+RDF
+data
+model.
+They
+are
+merely
+a
+syntactic
+convenience
+for
+abbreviating
+IRIs.
+</p>
+<p>
+The
+term
+“
+<dfn id="dfn-namespace">
+namespace
+</dfn>
+”
+on
+its
+own
+does
+not
+have
+a
+well-defined
+meaning
+in
+the
+context
+of
+RDF,
+but
+is
+sometimes
+informally
+used
+to
+mean
+“
+<a href="#dfn-namespace-iri" class="internalDFN">
+namespace
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+”
+or
+“
+<a href="#dfn-rdf-vocabulary" class="internalDFN">
+RDF
+vocabulary
+</a>
+”.
+</p>
+</section>
+<section id="change-over-time" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_change-over-time">
+<span class="secno">
+1.5
+</span>
+RDF
+and
+Change
+over
+Time
+</h3>
+<p>
+The
+RDF
+data
+model
+is
+<em>
+atemporal
+</em>:
+<a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graphs
+</a>
+are
+static
+snapshots
+of
+information.
+</p>
+<p>
+However,
+<a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graphs
+</a>
+can
+express
+information
+about
+events
+and
+about
+temporal
+aspects
+of
+other
+entities,
+given
+appropriate
+<a title="RDF vocabulary" href="#dfn-rdf-vocabulary" class="internalDFN">
+vocabulary
+</a>
+terms.
+</p>
+<p>
+Since
+<a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graphs
+</a>
+are
+defined
+as
+mathematical
+sets,
+adding
+or
+removing
+<a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">
+triples
+</a>
+from
+an
+RDF
+graph
+yields
+a
+different
+RDF
+graph.
+</p>
+<p>
+We
+informally
+use
+the
+term
+<dfn id="dfn-rdf-source">
+RDF
+source
+</dfn>
+to
+refer
+to
+a
+persistent
+yet
+mutable
+source
+or
+container
+of
+<a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graphs
+</a>.
+An
+RDF
+source
+is
+a
+<a href="#dfn-resource" class="internalDFN">
+resource
+</a>
+that
+may
+be
+said
+to
+have
+a
+state
+that
+can
+change
+over
+time.
+A
+snapshot
+of
+the
+state
+can
+be
+expressed
+as
+an
+RDF
+graph.
+For
+example,
+any
+web
+document
+that
+has
+an
+RDF-bearing
+representation
+may
+be
+considered
+an
+RDF
+source.
+Like
+all
+resources,
+RDF
+sources
+may
+be
+named
+with
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>
+and
+therefore
+described
+in
+other
+RDF
+graphs.
+</p>
+<p>
+Intuitively
+speaking,
+changes
+in
+the
+universe
+of
+discourse
+can
+be
+reflected
+in
+the
+following
+ways:
+</p>
+<ul>
+<li>
+An
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+once
+minted,
+should
+never
+change
+its
+intended
+<a href="#dfn-referent" class="internalDFN">
+referent
+</a>.
+(See
+<a href="http://www.w3.org/TR/webarch/#URI-persistence">
+<abbr title="Uniform Resource Identifier">
+URI
+</abbr>
+persistence
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-WEBARCH">
+WEBARCH
+</a>
+</cite>
+].)
+</li>
+<li>
+<a title="literal" href="#dfn-literal" class="internalDFN">
+Literals
+</a>,
+by
+design,
+are
+constants
+and
+never
+change
+their
+<a title="literal value" href="#dfn-literal-value" class="internalDFN">
+value
+</a>.
+</li>
+<li>
+A
+relationship
+that
+holds
+between
+two
+<a title="resource" href="#dfn-resource" class="internalDFN">
+resources
+</a>
+at
+one
+time
+may
+not
+hold
+at
+another
+time.
+</li>
+<li>
+<a title="RDF source" href="#dfn-rdf-source" class="internalDFN">
+RDF
+sources
+</a>
+may
+change
+their
+state
+over
+time.
+That
+is,
+they
+may
+provide
+different
+<a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graphs
+</a>
+at
+different
+times.
+</li>
+<li>
+Some
+<a title="RDF source" href="#dfn-rdf-source" class="internalDFN">
+RDF
+sources
+</a>
+may,
+however,
+be
+immutable
+snapshots
+of
+another
+RDF
+source,
+archiving
+its
+state
+at
+some
+point
+in
+time.
+</li>
+</ul>
+</section>
+<section id="managing-graphs" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_managing-graphs">
+<span class="secno">
+1.6
+</span>
+Working
+with
+Multiple
+RDF
+Graphs
+</h3>
+<p>
+As
+RDF
+graphs
+are
+sets
+of
+triples,
+they
+can
+be
+combined
+easily,
+supporting
+the
+use
+of
+data
+from
+multiple
+sources.
+Nevertheless,
+it
+is
+sometimes
+desirable
+to
+work
+with
+multiple
+RDF
+graphs
+while
+keeping
+their
+contents
+separate.
+<a title="RDF dataset" href="#dfn-rdf-dataset" class="internalDFN">
+RDF
+datasets
+</a>
+support
+this
+requirement.
+</p>
+<p>
+An
+<a href="#dfn-rdf-dataset" class="internalDFN">
+RDF
+dataset
+</a>
+is
+a
+collection
+of
+<a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graphs
+</a>.
+All
+but
+one
+of
+these
+graphs
+have
+an
+associated
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+blank
+node.
+They
+are
+called
+<a title="named graph" href="#dfn-named-graph" class="internalDFN">
+named
+graphs
+</a>,
+and
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+or
+blank
+node
+is
+called
+the
+<a href="#dfn-graph-name" class="internalDFN">
+graph
+name
+</a>.
+The
+remaining
+graph
+does
+not
+have
+an
+associated
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>,
+and
+is
+called
+the
+<a href="#dfn-default-graph" class="internalDFN">
+default
+graph
+</a>
+of
+the
+RDF
+dataset.
+</p>
+<p>
+There
+are
+many
+possible
+uses
+for
+<a title="RDF dataset" href="#dfn-rdf-dataset" class="internalDFN">
+RDF
+datasets
+</a>.
+One
+such
+use
+is
+to
+hold
+snapshots
+of
+multiple
+<a title="RDF source" href="#dfn-rdf-source" class="internalDFN">
+RDF
+sources
+</a>.
+</p>
+</section>
+<section id="entailment" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_entailment">
+<span class="secno">
+1.7
+</span>
+Equivalence,
+Entailment
+and
+Inconsistency
+</h3>
+<p>
+An
+<a href="#dfn-rdf-triple" class="internalDFN">
+RDF
+triple
+</a>
+encodes
+a
+<a title="RDF statement" href="#dfn-rdf-statement" class="internalDFN">
+statement
+</a>
+—a
+simple
+<dfn id="dfn-logical-expression">
+logical
+expression
+</dfn>,
+or
+claim
+about
+the
+world.
+An
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>
+is
+the
+conjunction
+(logical
+<em>
+AND
+</em>
+)
+of
+its
+triples.
+The
+precise
+details
+of
+this
+meaning
+of
+RDF
+triples
+and
+graphs
+are
+the
+subject
+of
+the
+RDF
+Semantics
+specification
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-MT">
+RDF11-MT
+</a>
+</cite>
+],
+which
+yields
+the
+following
+relationships
+between
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>
+s:
+</p>
+<dl>
+<dt>
+<dfn id="dfn-entailment">
+Entailment
+</dfn>
+</dt>
+<dd>
+An
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>
+<em>
+A
+</em>
+entails
+another
+RDF
+graph
+<em>
+B
+</em>
+if
+every
+possible
+arrangement
+of
+the
+world
+that
+makes
+<em>
+A
+</em>
+true
+also
+makes
+<em>
+B
+</em>
+true.
+When
+<em>
+A
+</em>
+entails
+<em>
+B
+</em>,
+if
+the
+truth
+of
+<em>
+A
+</em>
+is
+presumed
+or
+demonstrated
+then
+the
+truth
+of
+<em>
+B
+</em>
+is
+established.
+</dd>
+<dt>
+<dfn id="dfn-equivalence">
+Equivalence
+</dfn>
+</dt>
+<dd>
+Two
+<a title="RDF graph" href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graphs
+</a>
+<em>
+A
+</em>
+and
+<em>
+B
+</em>
+are
+equivalent
+if
+they
+make
+the
+same
+claim
+about
+the
+world.
+<em>
+A
+</em>
+is
+equivalent
+to
+<em>
+B
+</em>
+if
+and
+only
+if
+<em>
+A
+</em>
+<a title="entailment" href="#dfn-entailment" class="internalDFN">
+entails
+</a>
+<em>
+B
+</em>
+and
+<em>
+B
+</em>
+entails
+<em>
+A
+</em>.
+</dd>
+<dt>
+<dfn id="dfn-inconsistency">
+Inconsistency
+</dfn>
+</dt>
+<dd>
+An
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>
+is
+inconsistent
+if
+it
+contains
+an
+internal
+contradiction.
+There
+is
+no
+possible
+arrangement
+of
+the
+world
+that
+would
+make
+the
+expression
+true.
+</dd>
+</dl>
+<p>
+An
+<dfn id="dfn-entailment-regime">
+entailment
+regime
+</dfn>
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-MT">
+RDF11-MT
+</a>
+</cite>
+]
+is
+a
+specification
+that
+defines
+precise
+conditions
+that
+make
+these
+relationships
+hold.
+RDF
+itself
+recognizes
+only
+some
+basic
+cases
+of
+entailment,
+equivalence
+and
+inconsistency.
+Other
+specifications,
+such
+as
+<a href="http://www.w3.org/TR/rdf-schema/">
+RDF
+Schema
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-RDF11-SCHEMA">
+RDF11-SCHEMA
+</a>
+</cite>
+]
+and
+<a href="http://www.w3.org/TR/owl2-overview/">
+OWL
+2
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-OWL2-OVERVIEW">
+OWL2-OVERVIEW
+</a>
+</cite>
+],
+add
+more
+powerful
+entailment
+regimes,
+as
+do
+some
+domain-specific
+<a title="RDF vocabulary" href="#dfn-rdf-vocabulary" class="internalDFN">
+vocabularies
+</a>.
+</p>
+<p>
+This
+specification
+does
+not
+constrain
+how
+implementations
+use
+the
+logical
+relationships
+defined
+by
+<a title="entailment regime" href="#dfn-entailment-regime" class="internalDFN">
+entailment
+regimes
+</a>.
+Implementations
+may
+or
+may
+not
+detect
+<a title="inconsistency" href="#dfn-inconsistency" class="internalDFN">
+inconsistencies
+</a>,
+and
+may
+make
+all,
+some
+or
+no
+<a title="entailment" href="#dfn-entailment" class="internalDFN">
+entailed
+</a>
+information
+available
+to
+users.
+</p>
+</section>
+<section id="rdf-documents" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_rdf-documents">
+<span class="secno">
+1.8
+</span>
+RDF
+Documents
+and
+Syntaxes
+</h3>
+<p>
+An
+<dfn id="dfn-rdf-document">
+RDF
+document
+</dfn>
+is
+a
+document
+that
+encodes
+an
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>
+or
+<a href="#dfn-rdf-dataset" class="internalDFN">
+RDF
+dataset
+</a>
+in
+a
+<dfn id="dfn-concrete-rdf-syntax">
+concrete
+RDF
+syntax
+</dfn>,
+such
+as
+Turtle
+[
+<cite>
+<a class="bibref" href="#bib-TURTLE">
+TURTLE
+</a>
+</cite>
+],
+RDFa
+[
+<cite>
+<a class="bibref" href="#bib-RDFA-PRIMER">
+RDFA-PRIMER
+</a>
+</cite>
+],
+JSON-LD
+[
+<cite>
+<a class="bibref" href="#bib-JSON-LD">
+JSON-LD
+</a>
+</cite>
+],
+or
+TriG
+[
+<cite>
+<a class="bibref" href="#bib-TRIG">
+TRIG
+</a>
+</cite>
+].
+RDF
+documents
+enable
+the
+exchange
+of
+RDF
+graphs
+and
+RDF
+datasets
+between
+systems.
+</p>
+<p>
+A
+<a href="#dfn-concrete-rdf-syntax" class="internalDFN">
+concrete
+RDF
+syntax
+</a>
+may
+offer
+many
+different
+ways
+to
+encode
+the
+same
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>
+or
+<a href="#dfn-rdf-dataset" class="internalDFN">
+RDF
+dataset
+</a>,
+for
+example
+through
+the
+use
+of
+<a title="namespace prefix" href="#dfn-namespace-prefix" class="internalDFN">
+namespace
+prefixes
+</a>,
+relative
+IRIs,
+<a title="blank node identifier" href="#dfn-blank-node-identifier" class="internalDFN">
+blank
+node
+identifiers
+</a>,
+and
+different
+ordering
+of
+statements.
+While
+these
+aspects
+can
+have
+great
+effect
+on
+the
+convenience
+of
+working
+with
+the
+<a href="#dfn-rdf-document" class="internalDFN">
+RDF
+document
+</a>,
+they
+are
+not
+significant
+for
+its
+meaning.
+</p>
+</section>
+</section>
+<section id="conformance" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h2 aria-level="1" role="heading" id="h2_conformance">
+<span class="secno">
+2.
+</span>
+Conformance
+</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>
+The
+key
+words
+<em class="rfc2119" title="MUST">
+MUST
+</em>,
+<em class="rfc2119" title="MUST NOT">
+MUST
+NOT
+</em>,
+<em class="rfc2119" title="REQUIRED">
+REQUIRED
+</em>,
+<em class="rfc2119" title="SHOULD">
+SHOULD
+</em>,
+<em class="rfc2119" title="SHOULD NOT">
+SHOULD
+NOT
+</em>,
+<em class="rfc2119" title="RECOMMENDED">
+RECOMMENDED
+</em>,
+<em class="rfc2119" title="MAY">
+MAY
+</em>,
+and
+<em class="rfc2119" title="OPTIONAL">
+OPTIONAL
+</em>
+in
+this
+specification
+are
+to
+be
+interpreted
+as
+described
+in
+[
+<cite>
+<a class="bibref" href="#bib-RFC2119">
+RFC2119
+</a>
+</cite>
+].
+</p>
+<p>
+This
+specification,
+<em>
+RDF
+1.1
+Concepts
+and
+Abstract
+Syntax
+</em>,
+defines
+a
+data
+model
+and
+related
+terminology
+for
+use
+in
+other
+specifications,
+such
+as
+<a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">
+concrete
+RDF
+syntaxes
+</a>,
+API
+specifications,
+and
+query
+languages.
+Implementations
+cannot
+directly
+conform
+to
+<em>
+RDF
+1.1
+Concepts
+and
+Abstract
+Syntax
+</em>,
+but
+can
+conform
+to
+such
+other
+specifications
+that
+normatively
+reference
+terms
+defined
+here.
+</p>
+</section>
+<section id="section-rdf-graph" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h2 aria-level="1" role="heading" id="h2_section-rdf-graph">
+<span class="secno">
+3.
+</span>
+RDF
+Graphs
+</h2>
+<p>
+An
+<dfn id="dfn-rdf-graph">
+RDF
+graph
+</dfn>
+is
+a
+set
+of
+<a title="RDF triple" href="#dfn-rdf-triple" class="internalDFN">
+RDF
+triples
+</a>.
+</p>
+<section id="section-triples" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_section-triples">
+<span class="secno">
+3.1
+</span>
+Triples
+</h3>
+<p>
+An
+<dfn id="dfn-rdf-triple">
+RDF
+triple
+</dfn>
+consists
+of
+three
+components:
+</p>
+<ul>
+<li>
+the
+<dfn id="dfn-subject">
+subject
+</dfn>,
+which
+is
+an
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+a
+<a href="#dfn-blank-node" class="internalDFN">
+blank
+node
+</a>
+</li>
+<li>
+the
+<dfn id="dfn-predicate">
+predicate
+</dfn>,
+which
+is
+an
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+</li>
+<li>
+the
+<dfn id="dfn-object">
+object
+</dfn>,
+which
+is
+an
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-literal" class="internalDFN">
+literal
+</a>
+or
+a
+<a href="#dfn-blank-node" class="internalDFN">
+blank
+node
+</a>
+</li>
+</ul>
+<p>
+An
+RDF
+triple
+is
+conventionally
+written
+in
+the
+order
+subject,
+predicate,
+object.
+</p>
+<p>
+The
+set
+of
+<dfn title="node" id="dfn-node">
+nodes
+</dfn>
+of
+an
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>
+is
+the
+set
+of
+subjects
+and
+objects
+of
+triples
+in
+the
+graph.
+It
+is
+possible
+for
+a
+predicate
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+to
+also
+occur
+as
+a
+node
+in
+the
+same
+graph.
+</p>
+<p>
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>,
+<a title="literal" href="#dfn-literal" class="internalDFN">
+literals
+</a>
+and
+<a title="blank node" href="#dfn-blank-node" class="internalDFN">
+blank
+nodes
+</a>
+are
+collectively
+known
+as
+<dfn title="RDF term" id="dfn-rdf-term">
+RDF
+terms
+</dfn>.
+</p>
+<p>
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>,
+<a title="literal" href="#dfn-literal" class="internalDFN">
+literals
+</a>
+and
+<a title="blank node" href="#dfn-blank-node" class="internalDFN">
+blank
+nodes
+</a>
+are
+distinct
+and
+distinguishable.
+For
+example,
+<code>
+http://example.org/
+</code>
+as
+a
+string
+literal
+is
+neither
+equal
+to
+<code>
+http://example.org/
+</code>
+as
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>,
+nor
+to
+a
+blank
+node
+with
+the
+<a href="#dfn-blank-node-identifier" class="internalDFN">
+blank
+node
+identifier
+</a>
+<code>
+http://example.org/
+</code>.
+</p>
+</section>
+<section id="section-IRIs" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_section-IRIs">
+<span class="secno">
+3.2
+</span>
+IRIs
+</h3>
+<p>
+An
+<dfn title="IRI" id="dfn-iri">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>
+(Internationalized
+Resource
+Identifier)
+within
+an
+RDF
+graph
+is
+a
+Unicode
+string
+[
+<cite>
+<a class="bibref" href="#bib-UNICODE">
+UNICODE
+</a>
+</cite>
+]
+that
+conforms
+to
+the
+syntax
+defined
+in
+RFC
+3987
+[
+<cite>
+<a class="bibref" href="#bib-RFC3987">
+RFC3987
+</a>
+</cite>
+].
+</p>
+<p>
+IRIs
+in
+the
+RDF
+abstract
+syntax
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+be
+absolute,
+and
+<em class="rfc2119" title="MAY">
+MAY
+</em>
+contain
+a
+fragment
+identifier.
+</p>
+<p>
+<dfn id="dfn-iri-equality">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+equality
+</dfn>:
+Two
+IRIs
+are
+equal
+if
+and
+only
+if
+they
+are
+equivalent
+under
+Simple
+String
+Comparison
+according
+to
+<a href="http://tools.ietf.org/html/rfc3987#section-5.1">
+section
+5.1
+</a>
+of
+[
+<cite>
+<a class="bibref" href="#bib-RFC3987">
+RFC3987
+</a>
+</cite>
+].
+Further
+normalization
+<em class="rfc2119" title="MUST NOT">
+MUST
+NOT
+</em>
+be
+performed
+when
+comparing
+IRIs
+for
+equality.
+</p>
+<div class="note">
+<div class="note-title" aria-level="3" role="heading" id="h_note_1">
+<span>
+Note
+</span>
+</div>
+<div class="" id="note-iris">
+<p>
+<strong>
+URIs
+and
+IRIs:
+</strong>
+IRIs
+are
+a
+generalization
+of
+<dfn title="URI" id="dfn-uri">
+<abbr title="Uniform Resource Identifier">
+URI
+</abbr>
+s
+</dfn>
+[
+<cite>
+<a class="bibref" href="#bib-RFC3986">
+RFC3986
+</a>
+</cite>
+]
+that
+permits
+a
+wider
+range
+of
+Unicode
+characters.
+Every
+absolute
+<abbr title="Uniform Resource Identifier">
+URI
+</abbr>
+and
+URL
+is
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>,
+but
+not
+every
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+is
+an
+<abbr title="Uniform Resource Identifier">
+URI
+</abbr>.
+When
+IRIs
+are
+used
+in
+operations
+that
+are
+only
+defined
+for
+URIs,
+they
+must
+first
+be
+converted
+according
+to
+the
+mapping
+defined
+in
+<a href="http://tools.ietf.org/html/rfc3987#section-3.1">
+section
+3.1
+</a>
+of
+[
+<cite>
+<a class="bibref" href="#bib-RFC3987">
+RFC3987
+</a>
+</cite>
+].
+A
+notable
+example
+is
+retrieval
+over
+the
+HTTP
+protocol.
+The
+mapping
+involves
+UTF-8
+encoding
+of
+non-ASCII
+characters,
+%-encoding
+of
+octets
+not
+allowed
+in
+URIs,
+and
+Punycode-encoding
+of
+domain
+names.
+</p>
+<p>
+<strong>
+Relative
+IRIs:
+</strong>
+Some
+<a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">
+concrete
+RDF
+syntaxes
+</a>
+permit
+<dfn title="relative IRI" id="dfn-relative-iri">
+relative
+IRIs
+</dfn>
+as
+a
+convenient
+shorthand
+that
+allows
+authoring
+of
+documents
+independently
+from
+their
+final
+publishing
+location.
+Relative
+IRIs
+must
+be
+<a href="http://tools.ietf.org/html/rfc3986#section-5.2">
+resolved
+against
+</a>
+a
+<dfn id="dfn-base-iri">
+base
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>
+to
+make
+them
+absolute.
+Therefore,
+the
+RDF
+graph
+serialized
+in
+such
+syntaxes
+is
+well-defined
+only
+if
+a
+<a href="http://tools.ietf.org/html/rfc3986#section-5.1">
+base
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+can
+be
+established
+</a>
+[
+<cite>
+<a class="bibref" href="#bib-RFC3986">
+RFC3986
+</a>
+</cite>
+].
+</p>
+<p>
+<strong>
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+normalization:
+</strong>
+Interoperability
+problems
+can
+be
+avoided
+by
+minting
+only
+IRIs
+that
+are
+normalized
+according
+to
+<a href="http://tools.ietf.org/html/rfc3987#section-5">
+Section
+5
+</a>
+of
+[
+<cite>
+<a class="bibref" href="#bib-RFC3987">
+RFC3987
+</a>
+</cite>
+].
+Non-normalized
+forms
+that
+are
+best
+avoided
+include:
+</p>
+<ul>
+<li>
+Uppercase
+characters
+in
+scheme
+names
+and
+domain
+names
+</li>
+<li>
+Percent-encoding
+of
+characters
+where
+it
+is
+not
+required
+by
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+syntax
+</li>
+<li>
+Explicitly
+stated
+HTTP
+default
+port
+(
+<code>
+http://example.com:80/
+</code>
+);
+<code>
+http://example.com/
+</code>
+is
+preferable
+</li>
+<li>
+Completely
+empty
+path
+in
+HTTP
+IRIs
+(
+<code>
+http://example.com
+</code>
+);
+<code>
+http://example.com/
+</code>
+is
+preferable
+</li>
+<li>
+“
+<code>
+/./
+</code>
+”
+or
+“
+<code>
+/../
+</code>
+”
+in
+the
+path
+component
+of
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</li>
+<li>
+Lowercase
+hexadecimal
+letters
+within
+percent-encoding
+triplets
+(“
+<code>
+%3F
+</code>
+”
+is
+preferable
+over
+“
+<code>
+%3f
+</code>
+”)
+</li>
+<li>
+Punycode-encoding
+of
+Internationalized
+Domain
+Names
+in
+IRIs
+</li>
+<li>
+IRIs
+that
+are
+not
+in
+Unicode
+Normalization
+Form
+C
+[
+<cite>
+<a class="bibref" href="#bib-NFC">
+NFC
+</a>
+</cite>
+]
+</li>
+</ul>
+</div>
+</div>
+</section>
+<section id="section-Graph-Literal" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_section-Graph-Literal">
+<span class="secno">
+3.3
+</span>
+Literals
+</h3>
+<p>
+Literals
+are
+used
+for
+values
+such
+as
+strings,
+numbers,
+and
+dates.
+</p>
+<p>
+A
+<dfn id="dfn-literal">
+literal
+</dfn>
+in
+an
+<a href="#dfn-rdf-graph" class="internalDFN">
+RDF
+graph
+</a>
+consists
+of
+two
+or
+three
+elements:
+</p>
+<ul>
+<li>
+a
+<dfn id="dfn-lexical-form">
+lexical
+form
+</dfn>,
+being
+a
+Unicode
+[
+<cite>
+<a class="bibref" href="#bib-UNICODE">
+UNICODE
+</a>
+</cite>
+]
+string,
+which
+<em class="rfc2119" title="SHOULD">
+SHOULD
+</em>
+be
+in
+Normal
+<del class="diff-old">Form C
+</del>
+<ins class="diff-chg">Form&#160;C
+</ins>
+[
+<cite>
+<a class="bibref" href="#bib-NFC">
+NFC
+</a>
+</cite>
+],
+</li>
+<li>
+a
+<dfn id="dfn-datatype-iri">
+datatype
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>,
+being
+an
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+identifying
+a
+datatype
+that
+determines
+how
+the
+lexical
+form
+maps
+to
+a
+<a href="#dfn-literal-value" class="internalDFN">
+literal
+value
+</a>,
+and
+</li>
+<li>
+if
+and
+only
+if
+the
+<a href="#dfn-datatype-iri" class="internalDFN">
+datatype
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+<code>
+http://www.w3.org/1999/02/22-rdf-syntax-ns#langString
+</code>,
+a
+non-empty
+<dfn id="dfn-language-tag">
+language
+tag
+</dfn>
+as
+defined
+by
+[
+<cite>
+<a class="bibref" href="#bib-BCP47">
+BCP47
+</a>
+</cite>
+].
+The
+language
+tag
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+be
+well-formed
+according
+to
+<a href="http://tools.ietf.org/html/bcp47#section-2.2.9">
+section
+2.2.9
+</a>
+of
+[
+<cite>
+<a class="bibref" href="#bib-BCP47">
+BCP47
+</a>
+</cite>
+].
+</li>
+</ul>
+<p>
+A
+literal
+is
+a
+<dfn id="dfn-language-tagged-string">
+language-tagged
+string
+</dfn>
+if
+the
+third
+element
+is
+present.
+Lexical
+representations
+of
+language
+tags
+<em class="rfc2119" title="MAY">
+MAY
+</em>
+be
+converted
+to
+lower
+case.
+The
+value
+space
+of
+language
+tags
+is
+always
+in
+lower
+case.
+</p>
+<p>
+Please
+note
+that
+concrete
+syntaxes
+<em class="rfc2119" title="MAY">
+MAY
+</em>
+support
+<dfn title="simple literal" id="dfn-simple-literal">
+simple
+literals
+</dfn>
+consisting
+of
+only
+a
+<a href="#dfn-lexical-form" class="internalDFN">
+lexical
+form
+</a>
+without
+any
+<a href="#dfn-datatype-iri" class="internalDFN">
+datatype
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+<a href="#dfn-language-tag" class="internalDFN">
+language
+tag
+</a>.
+Simple
+literals
+are
+syntactic
+sugar
+for
+abstract
+syntax
+<a title="literal" href="#dfn-literal" class="internalDFN">
+literals
+</a>
+with
+the
+<a href="#dfn-datatype-iri" class="internalDFN">
+datatype
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+<code>
+http://www.w3.org/2001/XMLSchema#string
+</code>.
+Similarly,
+most
+concrete
+syntaxes
+represent
+<a title="language-tagged string" href="#dfn-language-tagged-string" class="internalDFN">
+language-tagged
+strings
+</a>
+without
+the
+<a href="#dfn-datatype-iri" class="internalDFN">
+datatype
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+because
+it
+always
+equals
+<code>
+http://www.w3.org/1999/02/22-rdf-syntax-ns#langString
+</code>.
+</p>
+<p>
+The
+<dfn id="dfn-literal-value">
+literal
+value
+</dfn>
+associated
+with
+a
+<a href="#dfn-literal" class="internalDFN">
+literal
+</a>
+is:
+</p>
+<ol>
+<li>
+If
+the
+literal
+is
+a
+<a href="#dfn-language-tagged-string" class="internalDFN">
+language-tagged
+string
+</a>,
+then
+the
+literal
+value
+is
+a
+pair
+consisting
+of
+its
+<a href="#dfn-lexical-form" class="internalDFN">
+lexical
+form
+</a>
+and
+its
+<a href="#dfn-language-tag" class="internalDFN">
+language
+tag
+</a>,
+in
+that
+order.
+</li>
+<li>
+If
+the
+literal's
+<a href="#dfn-datatype-iri" class="internalDFN">
+datatype
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+in
+the
+set
+of
+<a href="#dfn-recognized-datatype-iris" class="internalDFN">
+recognized
+datatype
+IRIs
+</a>,
+let
+<var>
+d
+</var>
+be
+the
+<a href="#dfn-referent" class="internalDFN">
+referent
+</a>
+of
+the
+datatype
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>.
+<ol>
+<li>
+If
+the
+literal's
+<a href="#dfn-lexical-form" class="internalDFN">
+lexical
+form
+</a>
+is
+in
+the
+<a href="#dfn-lexical-space" class="internalDFN">
+lexical
+space
+</a>
+of
+<var>
+d
+</var>,
+then
+the
+literal
+value
+is
+the
+result
+of
+applying
+the
+<a href="#dfn-lexical-to-value-mapping" class="internalDFN">
+lexical-to-value
+mapping
+</a>
+of
+<var>
+d
+</var>
+to
+the
+<a href="#dfn-lexical-form" class="internalDFN">
+lexical
+form
+</a>.
+</li>
+<li>
+Otherwise,
+the
+literal
+is
+ill-typed
+and
+no
+literal
+value
+can
+be
+associated
+with
+the
+literal.
+Such
+a
+case
+produces
+a
+semantic
+inconsistency
+but
+is
+not
+<em>
+syntactically
+</em>
+ill-formed.
+Implementations
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+accept
+ill-typed
+literals
+and
+produce
+RDF
+graphs
+from
+them.
+Implementations
+<em class="rfc2119" title="MAY">
+MAY
+</em>
+produce
+warnings
+when
+encountering
+ill-typed
+literals.
+</li>
+</ol>
+</li>
+<li>
+If
+the
+literal's
+<a href="#dfn-datatype-iri" class="internalDFN">
+datatype
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+<em>
+not
+</em>
+in
+the
+set
+of
+<a href="#dfn-recognized-datatype-iris" class="internalDFN">
+recognized
+datatype
+IRIs
+</a>,
+then
+the
+literal
+value
+is
+not
+defined
+by
+this
+specification.
+</li>
+</ol>
+<p>
+<dfn id="dfn-literal-term-equality">
+Literal
+term
+equality
+</dfn>:
+Two
+literals
+are
+term-equal
+(the
+same
+RDF
+literal)
+if
+and
+only
+if
+the
+two
+<a title="lexical form" href="#dfn-lexical-form" class="internalDFN">
+lexical
+forms
+</a>,
+the
+two
+<a title="datatype IRI" href="#dfn-datatype-iri" class="internalDFN">
+datatype
+IRIs
+</a>,
+and
+the
+two
+<a title="language tag" href="#dfn-language-tag" class="internalDFN">
+language
+tags
+</a>
+(if
+any)
+compare
+equal,
+character
+by
+character.
+Thus,
+two
+literals
+can
+have
+the
+same
+value
+without
+being
+the
+same
+RDF
+term.
+For
+example:
+</p>
+<del class="diff-old">          &quot;1&quot;^^xs:integer
+      &quot;01&quot;^^xs:integer
+</del>
+<pre>
+<ins class="diff-chg">      "1"^^xs:integer
+      "01"^^xs:integer
+    
+</ins>
+</pre>
+<p>
+denote
+the
+same
+<a title="literal value" href="#dfn-literal-value" class="internalDFN">
+value
+</a>,
+but
+are
+not
+the
+same
+literal
+<a title="RDF Term" href="#dfn-rdf-term" class="internalDFN">
+RDF
+terms
+</a>
+and
+are
+not
+<a title="literal term equality" href="#dfn-literal-term-equality" class="internalDFN">
+term-equal
+</a>
+because
+their
+<a href="#dfn-lexical-form" class="internalDFN">
+lexical
+form
+</a>
+differs.
+</p>
+</section>
+<section id="section-blank-nodes" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_section-blank-nodes">
+<span class="secno">
+3.4
+</span>
+Blank
+Nodes
+</h3>
+<p>
+<dfn title="blank node" id="dfn-blank-node">
+Blank
+nodes
+</dfn>
+are
+disjoint
+from
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>
+and
+<a title="literal" href="#dfn-literal" class="internalDFN">
+literals
+</a>.
+Otherwise,
+the
+set
+of
+possible
+blank
+nodes
+is
+arbitrary.
+RDF
+makes
+no
+reference
+to
+any
+internal
+structure
+of
+blank
+nodes.
+</p>
+<div class="note">
+<div class="note-title" aria-level="3" role="heading" id="h_note_2">
+<span>
+Note
+</span>
+</div>
+<p class="" id="note-bnode-id">
+<dfn title="blank node identifier" id="dfn-blank-node-identifier">
+Blank
+node
+identifiers
+</dfn>
+are
+local
+identifiers
+that
+are
+used
+in
+some
+<a title="concrete RDF syntax" href="#dfn-concrete-rdf-syntax" class="internalDFN">
+concrete
+RDF
+syntaxes
+</a>
+or
+RDF
+store
+implementations.
+They
+are
+always
+locally
+scoped
+to
+the
+file
+or
+RDF
+store,
+and
+are
+<em>
+not
+</em>
+persistent
+or
+portable
+identifiers
+for
+blank
+nodes.
+Blank
+node
+identifiers
+are
+<em>
+not
+</em>
+part
+of
+the
+RDF
+abstract
+syntax,
+but
+are
+entirely
+dependent
+on
+the
+concrete
+syntax
+or
+implementation.
+The
+syntactic
+restrictions
+on
+blank
+node
+identifiers,
+if
+any,
+therefore
+also
+depend
+on
+the
+concrete
+RDF
+syntax
+or
+implementation.
+Implementations
+that
+handle
+blank
+node
+identifiers
+in
+concrete
+syntaxes
+need
+to
+be
+careful
+not
+to
+create
+the
+same
+blank
+node
+from
+multiple
+occurrences
+of
+the
+same
+blank
+node
+identifier
+except
+in
+situations
+where
+this
+is
+supported
+by
+the
+syntax.
+</p>
+</div>
+</section>
+<section id="section-skolemization" typeof="bibo:Chapter" resource="#ref" rel="bibo:Chapter">
+<h3 aria-level="2" role="heading" id="h3_section-skolemization">
+<span class="secno">
+3.5
+</span>
+Replacing
+Blank
+Nodes
+with
+IRIs
+</h3>
+<p>
+Blank
+nodes
+do
+not
+have
+identifiers
+in
+the
+RDF
+abstract
+syntax.
+The
+<a title="blank node identifier" href="#dfn-blank-node-identifier" class="internalDFN">
+blank
+node
+identifiers
+</a>
+introduced
+by
+some
+concrete
+syntaxes
+have
+only
+local
+scope
+and
+are
+purely
+an
+artifact
+of
+the
+serialization.
+</p>
+<p>
+In
+situations
+where
+stronger
+identification
+is
+needed,
+systems
+<em class="rfc2119" title="MAY">
+MAY
+</em>
+systematically
+replace
+some
+or
+all
+of
+the
+blank
+nodes
+in
+an
+RDF
+graph
+with
+<a title="IRI" href="#dfn-iri" class="internalDFN">
+IRIs
+</a>.
+Systems
+wishing
+to
+do
+this
+<em class="rfc2119" title="SHOULD">
+SHOULD
+</em>
+mint
+a
+new,
+globally
+unique
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+(a
+<dfn id="dfn-skolem-iri">
+Skolem
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>
+)
+for
+each
+blank
+node
+so
+replaced.
+</p>
+<p>
+This
+transformation
+does
+not
+appreciably
+change
+the
+meaning
+of
+an
+RDF
+graph,
+provided
+that
+the
+Skolem
+IRIs
+do
+not
+occur
+anywhere
+else.
+It
+does
+however
+permit
+the
+possibility
+of
+other
+graphs
+subsequently
+using
+the
+Skolem
+IRIs,
+which
+is
+not
+possible
+for
+blank
+nodes.
+</p>
+<p>
+Systems
+may
+wish
+to
+mint
+Skolem
+IRIs
+in
+such
+a
+way
+that
+they
+can
+recognize
+the
+IRIs
+as
+having
+been
+introduced
+solely
+to
+replace
+blank
+nodes.
+This
+allows
+a
+system
+to
+map
+IRIs
+back
+to
+blank
+nodes
+if
+needed.
+</p>
+<p>
+Systems
+that
+want
+Skolem
+IRIs
+to
+be
+recognizable
+outside
+of
+the
+system
+boundaries
+<em class="rfc2119" title="SHOULD">
+SHOULD
+</em>
+use
+a
+well-known
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+[
+<cite>
+<a class="bibref" href="#bib-RFC5785">
+RFC5785
+</a>
+</cite>
+]
+with
+the
+registered
+name
+<code>
+genid
+</code>.
+This
+is
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+that
+uses
+the
+HTTP
+or
+HTTPS
+scheme,
+or
+another
+scheme
+that
+has
+been
+specified
+to
+use
+well-known
+IRIs;
+and
+whose
+path
+component
+starts
+with
+<code>
+/.well-known/genid/
+</code>.
+</p>
+<p>
+For
+example,
+the
+authority
+responsible
+for
+the
+domain
+<code>
+example.com
+</code>
+could
+mint
+the
+following
+recognizable
+Skolem
+<abbr title="Internationalized Resource Identifier">
+IRI