Move rdf-concepts stuff into subdirectory
authorRichard Cyganiak <richard@cyganiak.de>
Wed, 01 Jun 2011 19:12:07 +0100
changeset 26 8b9b0aa39f97
parent 25 b604bf2608d3
child 27 2cc3054015f2
Move rdf-concepts stuff into subdirectory
Graph-ex.gif
fig6may19
index.html
rdf-concepts/Graph-ex.gif
rdf-concepts/fig6may19
rdf-concepts/index.html
Binary file Graph-ex.gif has changed
Binary file fig6may19 has changed
--- a/index.html	Wed Jun 01 19:04:40 2011 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1563 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-  <head>
-    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
-    <title>RDF 1.1 Concepts and Abstract Syntax</title>
-    <style>
-.figure { font-weight: bold; text-align: center; }
-    </style>
-    <script src='ReSpec.js/js/respec.js' class='remove'></script>
-    <script class='remove'>
-      var respecConfig = {
-          // specification status (e.g. WD, LCWD, NOTE, etc.). If in doubt use ED.
-          specStatus:           "ED",
-          
-          // the specification's short name, as in http://www.w3.org/TR/short-name/
-          shortName:            "rdf11-concepts",
-
-          // if your specification has a subtitle that goes below the main
-          // formal title, define it here
-          // subtitle   :  "an excellent document",
-
-          // if you wish the publication date to be other than today, set this
-          // publishDate:  "2009-08-06",
-
-          // if the specification's copyright date is a range of years, specify
-          // the start date here:
-          copyrightStart: "2004",
-
-          // if there is a previously published draft, uncomment this and set its YYYY-MM-DD date
-          // and its maturity status
-//          previousPublishDate:  "2004-02-10",
-//          previousMaturity:  "REC",
-
-          // if there a publicly available Editor's Draft, this is the link
-//@@@
-          edDraftURI:           "http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html",
-
-          // if this is a LCWD, uncomment and set the end of its review period
-          // lcEnd: "2009-08-05",
-
-          // if there is an earler version of this specification at the Recommendation level,
-          // set this to the shortname of that version. This is optional and not usually
-          // necessary.
-          prevRecShortname: "rdf-concepts",
-
-          // if you want to have extra CSS, append them to this list
-          // it is recommended that the respec.css stylesheet be kept
-          extraCSS:             ["http://dev.w3.org/2009/dap/ReSpec.js/css/respec.css"],
-
-          // editors, add as many as you like
-          // only "name" is required
-          editors:  [
-              { name: "Richard Cyganiak", url: "http://richard.cyganiak.de/",
-                company: "DERI, NUI Galway", companyURL: "http://www.deri.ie/",
-              },
-// @@@ Details for David?
-              { name: "David Wood", // url: "http://example.org/",
-                company: "Talis", companyURL: "http://www.talis.com/",
-              },
-          ],
-          otherContributors: {
-              "Previous editor": [
-// @@@ Graham's affiliation has changed
-                  { name: "Graham Klyne",
-                    url: "http://www.ninebynine.org/",
-                    company: "Nine by Nine",
-                    //companyURL: "http://example.com/"
-                    //mailto: "[email protected]",
-                  },
-// @@@ Jeremy's affiliation has changed
-                  { name: "Jeremy J. Carroll",
-                    //url: "http://www-uk.hpl.hp.com/people/jjc/",
-                    company: "Hewlett Packard Labs",
-                    //companyURL: "http://example.com/"
-                    //mailto: "[email protected]",
-                  },
-// @@@ Brian's affiliation has changed
-                  { name: "Brian McBride",
-                    //url: "http://www-uk.hpl.hp.com/people/bwm/",
-                    company: "Hewlett Packard Labs",
-                    //companyURL: "http://example.com/"
-                    //mailto: "[email protected]",
-                    note: "RDF 2004 Series Editor",
-                  },
-              ],
-          },
-
-          // authors, add as many as you like. 
-          // This is optional, uncomment if you have authors as well as editors.
-          // only "name" is required. Same format as editors.
-
-          //authors:  [
-          //    { name: "Your Name", url: "http://example.org/",
-          //      company: "Your Company", companyURL: "http://example.com/" },
-          //],
-          
-          // name of the WG
-          wg:           "RDF Working Group",
-          
-          // URI of the public WG page
-          wgURI:        "http://www.w3.org/2011/rdf-wg/",
-          
-          // name (with the @w3c.org) of the public mailing to which comments are due
-          wgPublicList: "public-rdf-comments",
-          
-          // URI of the patent status for this WG, for Rec-track documents
-          // !!!! IMPORTANT !!!!
-          // This is important for Rec-track documents, do not copy a patent URI from a random
-          // document unless you know what you're doing. If in doubt ask your friendly neighbourhood
-          // Team Contact.
-          wgPatentURI:  "http://www.w3.org/2004/01/pp-impl/46168/status",
-
-          // if this parameter is set to true, ReSpec.js will embed various RDFa attributes
-          // throughout the generated specification. The triples generated use vocabulary items
-          // from the dcterms, foaf, and bibo. The parameter defaults to false.
-          doRDFa: true,
-      };
-
-// @@@ A number of references have been patched into the local berjon.biblio and need to be added to the global biblio in CVS:
-    </script>
-  </head>
-
-  <body>
-
-<section id="abstract">
-    <p>The Resource Description Framework (RDF) is a framework for
-    representing information in the Web.</p>
-    <p>RDF Concepts and Abstract Syntax defines an abstract syntax
-    on which RDF is based, and which serves to link its concrete
-    syntax to its formal semantics. It also includes discussion of
-    design goals, key concepts, datatyping, character normalization
-    and handling of IRIs.</p>
-</section>
-
-
-<section id="section-Introduction">
-    <h2>Introduction</h2>
-
-    <p class="issue">This document reflects current progress of the RDF Working
-      Group towards updating the
-      <a href="http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/">2004
-      version of <em>RDF Concepts and Abstract Syntax</em></a>. The
-      editors expect to work on a number of issues, some of which are
-      listed in boxes like this throughout the document.</p>
-
-    <p>The Resource Description Framework (RDF) is a framework for
-    representing information in the Web.</p>
-
-    <p>This document defines an abstract syntax on which RDF is based,
-    and which serves to link its concrete syntax to its formal
-    semantics. 
-This abstract syntax is quite distinct from XML's tree-based infoset
-    [[XML-INFOSET]]. It also includes discussion of design goals, 
-    key concepts, datatyping, character normalization
-    and handling of IRIs.</p>
-
-    <p>Normative documentation of RDF falls into the following
-    areas:</p>
-
-    <ul>
-      <li>XML serialization syntax [[!RDF-SYNTAX-GRAMMAR]],</li>
-
-      <li>formal semantics [[!RDF-MT]], and</li>
-
-      <li>this document (sections 4, 5, 6 and 7).</li>
-    </ul>
-
-    <p class="issue">This document was written when RDF/XML was the
-    only normative syntax. Now it is just one of many syntaxes and
-    it should be de-emphasized accordingly. There is no reason why
-    it should be a normative reference in this document.</p>
-
-    <p>The framework is designed so that vocabularies can be layered.  
-The RDF and RDF vocabulary definition (RDF schema) 
-languages 
-    [[RDF-SCHEMA]] are the first
-    such vocabularies.
- 
-    Others (cf. OWL [[OWL-REF]] and
-    the applications mentioned in the primer 
-    [[RDF-PRIMER]]) are in development.</p>
-</section>
-
-
-<section id="conformance"></section>
-
-
-<section id="section-Overview" class="informative">
-    <h2>Motivations and Goals</h2>
-
-    <p class="issue">Does this section add value?</p>
-
-    <p>RDF has an abstract syntax that reflects a simple graph-based
-    data model, and formal semantics with a rigorously defined notion
-    of entailment providing a basis for well founded deductions in RDF
-    data.</p>
-
-<section id="section-motivation">
-    <h3>Motivation</h3>
-
-    <p>The development of RDF has been motivated by the following uses,
-    among others:</p>
-
-    <ul>
-      <li>Web metadata: providing information about Web resources and
-      the systems that use them (e.g. content rating, capability
-      descriptions, privacy preferences, etc.)</li>
-
-      <li>Applications that require open rather than constrained
-      information models (e.g. scheduling activities, describing
-      organizational processes, annotation of Web resources, etc.)</li>
-
-      <li>To do for machine processable information (application data)
-      what the World Wide Web has done for hypertext: to allow data to
-      be processed outside the particular environment in which it was
-      created, in a fashion that can work at Internet scale.</li>
-
-      <li>Interworking among applications: combining data from several
-      applications to arrive at new information.</li>
-
-      <li>Automated processing of Web information by software agents:
-      the Web is moving from having just human-readable information to
-      being a world-wide network of cooperating processes. RDF provides
-      a world-wide lingua franca for these processes.</li>
-    </ul>
-
-    <p>RDF is designed to represent information in a minimally
-    constraining, flexible way. It can be used in isolated
-    applications, where individually designed formats 
-    might be more direct and easily understood,  but RDF's generality offers greater value from
-    sharing. The value of information thus increases as it becomes
-    accessible to more applications across the entire Internet.</p>
-</section>
-
-
-<section>
-    <h3 id="section-design-goals">Design Goals</h3>
-
-    <p>The design of RDF is intended to meet the following goals:</p>
-
-    <ul>
-      <li>having a simple data model</li>
-      <li>having formal semantics and provable inference</li>
-      <li>using an extensible IRI-based vocabulary</li>
-      <li>using an XML-based syntax</li>
-      <li>supporting use of XML schema datatypes</li>
-      <li>allowing anyone to make statements about any
-      resource</li>
-   </ul>
-
-
-<section id="section-simple-data-model">
-    <h4>A Simple Data Model</h4>
-
-    <p>RDF has a simple data model that is easy for applications to
-    process and manipulate. The data model is independent of any
-    specific serialization syntax.</p>
-
-      <p class="note">The term “model” used here in “data model” has a
-      completely different sense to its use in the term “model theory”.
-      See  [[!RDF-MT]] 
-      for more information about “model theory” as used in the literature of mathematics and logic.</p>
-</section>
-
-
-<section id="section-formal-semantics">
-    <h4>Formal Semantics and Inference</h4>
-
-    <p>RDF has a formal semantics which provides a dependable basis for
-    reasoning about the meaning of an RDF expression. In particular, it
-    supports rigorously defined notions of entailment which provide a
-    basis for defining reliable rules of inference in RDF data.</p>
-</section>
-
-
-<section id="section-extensible-vocab">
-    <h4>Extensible IRI-based Vocabulary</h4>
-
-    <p>The vocabulary is fully extensible, being based on IRIs.
-    IRIs are used for naming all kinds of things in RDF.</p>
-
-    <p>The other kind of value that appears in RDF data is a
-    literal.</p>
-</section>
-
-
-<section id="section-xml-serialization">
-    <h4>XML-based Syntax</h4>
-
-    <p>RDF has a recommended XML serialization form [[!RDF-SYNTAX-GRAMMAR]], which can be used to encode the
-    data model for exchange of information among applications.</p>
-</section>
-
-
-<section id="section-use-xsd">
-    <h4>Use XML Schema Datatypes</h4>
-
-    <p>RDF can use values represented according to XML schema datatypes
-    [[!XMLSCHEMA-2]], thus assisting the
-    exchange of information between RDF and other XML applications.</p>
-</section>
-
-
-<section id="section-anyone">
-    <h4>Anyone Can Make Statements About Any Resource</h4>
-
-    <p>To facilitate operation at Internet scale, RDF is an
-    open-world framework that allows anyone to make statements
-    about any resource.</p>
-    <p>In general, it is not assumed that complete information
-    about any resource is available. RDF does not prevent anyone
-    from making assertions that are nonsensical or inconsistent
-    with other statements, or the world as people see it. Designers
-    of applications that use RDF should be aware of this and may
-    design their applications to tolerate incomplete or
-    inconsistent sources of information.</p>
-</section>
-
-</section>
-
-</section>
-
-
-<section id="section-Concepts" class="informative">
-    <h2>RDF Concepts</h2>
-
-    <p class="issue">This section is quite redundant with later normative sections and the RDF Primer.</p>
-
-    <p>RDF uses the following key concepts:</p>
-
-    <ul>
-      <li>Graph data model</li>
-
-      <li>IRI-based vocabulary</li>
-
-      <li>Datatypes</li>
-
-      <li>Literals</li>
-
-      <li>XML serialization syntax</li>
-
-      <li>Expression of simple facts</li>
-
-      <li>Entailment</li>
-    </ul>
-
-
-<section id="section-data-model">
-    <h3>Graph Data Model</h3>
-
-    <p>The underlying structure of any expression in RDF is a
-    collection of triples, each consisting of a subject, a
-    predicate and an object. A set of such triples is called an RDF
-    graph (defined more formally in 
-<a href="#section-Graph-syntax">section 6</a>). This can be
-    illustrated by a node and directed-arc diagram, in which each
-    triple is represented as a node-arc-node link (hence the term
-    “graph”).</p>
-
-    <div class="figure">
-      <img src="Graph-ex.gif" alt="image of the RDF triple comprising (subject, predicate, object)" />
-    </div>
-
-    <p>Each triple represents a statement of a relationship between
-    the things denoted by the nodes that it links. Each triple has
-    three parts:</p>
-    <ol>
-      <li>a <a>subject</a>,</li>
-      <li>an <a>object</a>, and</li>
-      <li>a <a>predicate</a> (also called a
-      <a>property</a>) that denotes a
-      relationship.</li>
-    </ol>
-    <p>The direction of the arc is significant: it always points
-    toward the object.</p>
-    <p>The <a title="node">nodes</a> of an RDF graph
-    are its subjects and objects.</p>
-    <p>The assertion of an RDF triple says that some relationship,
-    indicated by the predicate, holds between the things denoted by
-    subject and object of the triple. The assertion of an RDF graph
-    amounts to asserting all the triples in it, so the meaning of
-    an RDF graph is the conjunction (logical AND) of the statements
-    corresponding to all the triples it contains. A formal account
-    of the meaning of RDF graphs is given in [[!RDF-MT]].</p>
-</section>
-
-
-<section id="section-IRI-Vocabulary">
-    <h3>IRI-based Vocabulary and Node Identification</h3>
-
-    <p>A <a>node</a> may be an <a>IRI</a>, a <a>literal</a>,
-    or <a title="blank node">blank</a> (having no separate form of identification).
-    Properties are <a title="IRI">IRIs</a>.</p>
-    <p>An <a>IRI</a> or <a>literal</a> used as a node identifies what
-    that node represents. An IRI used as a predicate
-    identifies a relationship between the things represented by the nodes it connects. A
-    predicate IRI may also be a node in the graph.</p>
-    <p>A <a>blank node</a> is a node that is
-    not an IRI or a literal. In the RDF abstract syntax, a
-    blank node is just a unique node that can be used in one or
-    more RDF statements.</p>
-    <p>A convention used by some linear representations of an RDF
-    graph to allow several statements to use the same
-    blank node is to use a <dfn>blank node
-    identifier</dfn>, which is a local identifier that can be
-    distinguished from all IRIs and literals. When graphs are
-    merged, their blank nodes must be kept distinct if meaning is
-    to be preserved; this may call for re-allocation of blank node
-    identifiers. Note that such blank node identifiers are not part
-    of the RDF abstract syntax, and the representation of triples
-    containing blank nodes is entirely dependent on the particular
-    concrete syntax used.</p>
-</section>
-
-
-<section name="section-Datatypes-intro">
-    <h3>Datatypes</h3>
-
-    <p>Datatypes are used by RDF in the representation of values such
-    as integers, floating point numbers and dates.</p>
-
- <p>
-A datatype consists of a lexical space, a value space and a lexical-to-value 
-mapping, see <a href="#section-Datatypes">section 5</a>.
-</p>
-
-    <p>For example, the lexical-to-value mapping for the XML Schema datatype
-    <var>xsd:boolean</var>, where each member of the value space
-    (represented here as 'T' and 'F') has two lexical representations,
-    is as follows:</p>
-
-    <table border="1" cellpadding="5" summary=
-    "A table detailing the xsd:boolean datatype.">
-      <tr>
-        <th align="left">Value Space</th>
-
-        <td>{T, F}</td>
-      </tr>
-
-      <tr>
-        <th align="left">Lexical Space</th>
-
-        <td>{"0", "1", "true", "false"}</td>
-      </tr>
-
-      <tr>
-        <th align="left">Lexical-to-Value Mapping</th>
-
-        <td>{&lt;"true", T&gt;, &lt;"1", T&gt;, &lt;"0", F&gt;,
-        &lt;"false", F&gt;}</td>
-      </tr>
-    </table>
-
-    <p>RDF predefines just one datatype <code><a>rdf:XMLLiteral</a></code>, used for
-    embedding XML in RDF (see <a href="#section-XMLLiteral">section
-    5.1</a>).</p>
-
-    <p>There is no built-in concept of numbers or dates or other common
-    values. Rather, RDF defers to datatypes that are defined
-    separately, and identified with <a title="IRI">IRIs</a>.
-    The predefined XML Schema
-    datatypes [[!XMLSCHEMA-2]] are expected
-    to be widely used for this purpose.</p>
-
-
-    <p>RDF provides no mechanism for defining new datatypes. XML Schema
-    Datatypes [[!XMLSCHEMA-2]] provides an
-    extensibility framework suitable for defining new datatypes for use
-    in RDF.</p>
-</section>
-
-
-<section name="section-Literals">
-    <h3> Literals</h3>
-
-    <p><a title="literal">Literals</a> are used to identify values such as numbers and dates
-    by means of a lexical representation. Anything represented by a
-    literal could also be represented by an <a>IRI</a>, but it is often more
-    convenient or intuitive to use literals.</p>
-
-    <p>A literal may be the object of an RDF statement, but not the
-    subject or the predicate.</p>
-
-    <p>Literals may be <cite>plain</cite> or <cite>typed</cite> :</p>
-
-    <ul>
-      <li>A <a>plain literal</a> is a string combined
-      with an optional language tag. This may be used for
-      plain text in a natural language. As recommended in the RDF
-      formal semantics [[!RDF-MT]], these plain literals are
-      self-denoting.</li>
-
-
-
-      <li>A <a>typed literal</a> is a string combined with a
-      <a>datatype IRI</a>. It denotes the
-      member of the identified datatype's value space obtained by
-      applying the lexical-to-value mapping to the literal string.</li>
-    </ul>
-
-    <p>Continuing the example from <a href="#section-Datatypes-intro">section
-    3.3</a>, the typed literals that can be defined using the XML
-    Schema datatype <var>xsd:boolean</var> are:</p>
-
-    <table border="1" cellpadding="5" summary=
-    "This table lists the literals of type xsd:boolean.">
-      <tr>
-        <th>Typed Literal</th>
-
-        <th>Lexical-to-Value Mapping</th>
-
-        <th>Value</th>
-      </tr>
-
-      <tr>
-        <td align="center">&lt;xsd:boolean, "true"&gt;</td>
-
-        <td align="center">&lt;"true", T&gt;</td>
-
-        <td align="center">T</td>
-      </tr>
-
-      <tr>
-        <td align="center">&lt;xsd:boolean, "1"&gt;</td>
-
-        <td align="center">&lt;"1", T&gt;</td>
-
-        <td align="center">T</td>
-      </tr>
-
-      <tr>
-        <td align="center">&lt;xsd:boolean, "false"&gt;</td>
-
-        <td align="center">&lt;"false", F&gt;</td>
-
-        <td align="center">F</td>
-      </tr>
-
-      <tr>
-        <td align="center">&lt;xsd:boolean, "0"&gt;</td>
-
-        <td align="center">&lt;"0", F&gt;</td>
-
-        <td align="center">F</td>
-      </tr>
-    </table>
-
-    <p>For text that may contain 
-    markup, use typed literals
-with type <a href="#section-XMLLiteral">rdf:XMLLiteral</a>.
-If language annotation is required, 
-it    must be explicitly included as markup, usually by means of an 
-<code>xml:lang</code> attribute. 
-[[XHTML10]] may be included within RDF
-in this way. Sometimes, in this latter case, 
- an additional <code>span</code> or <code>div</code> 
-    element is needed to carry an
-<code>xml:lang</code> or <code>lang</code> attribute. 
-    </p>
-
-<p>
-The string in both plain and typed literals is recommended to
-be in Unicode Normal Form C [[!NFC]]. This is motivated
-by [[CHARMOD]] particularly 
-<a href="http://www.w3.org/TR/2003/WD-charmod-20030822/#sec-Normalization">section 4 
-Early Uniform Normalization</a>.
-</p>
-
-</section>
-
-
-<section id="section-SimpleFacts">
-    <h3>RDF Expression of Simple Facts</h3>
-
-    <p>Some simple facts indicate a relationship between
-       two things. 
-Such a fact may be represented as an RDF triple in which the predicate 
-names the relationship, and the subject and object denote the two things.
-
-
-     A familiar representation of such a fact might be
-    as a row in a table in a relational database. The table has
-    two columns, corresponding to the subject and the object of the 
-    RDF triple. 
-    The name of the table corresponds to the predicate
-    of the RDF triple. A further familiar representation may be as a 
-    two place predicate
-    in first order logic.</p>
-    
-    <p>
-Relational databases permit a table to have an arbitrary number of columns, 
-a row of which expresses information corresponding to a predicate in first 
-order logic with an arbitrary number of places.  Such a row, or predicate, 
-has to be decomposed for representation as RDF triples.  A simple form of 
-decomposition introduces a new blank node, corresponding to the row, and a 
-new triple is introduced for each cell in the row.  The subject of each 
-triple is the new blank node, the predicate corresponds to the column name, 
-and object corresponds to the value in the cell.  The new blank node may 
-also have an <code>rdf:type</code> property whose value corresponds 
-to the table name.
-</p>
-    
-   <p>As an example, consider Figure 6 from the [[RDF-PRIMER]]:
-
-</p>
-
-    <div class="figure">
-      <img src="fig6may19" alt="Using a Blank Node" /><br />
-      RDF Primer Figure 6: Using a Blank Node
-    </div>
-
-
- <p>
-This information might correspond to a row in a table <code>"STAFFADDRESSES"</code>,
- with a primary key 
-<code>STAFFID</code>,
- and additional columns 
-<code>STREET</code>,
-<code>STATE</code>,
-<code>CITY</code> and
-<code>POSTALCODE</code>.
-  </p>
-
-    <p>
-Thus, a more complex fact is expressed in RDF using a 
-conjunction (logical-AND) of simple binary relationships.  RDF does not 
-provide means to express negation (NOT) or disjunction (OR).  </p>
-
-    <p>Through its use of extensible IRI-based vocabularies, RDF
-    provides for expression of facts about arbitrary subjects; i.e.
-    assertions of named properties about specific named things. An IRI
-    can be constructed for any thing that can be named, so RDF facts
-    can be about any such things. <!--
-            And, as noted above, RDF also
-            provides for expression of assertions about unnamed things, which
-            may be fully identifiable in terms of such assertions [[TAP-RBD]].
-            -->
-    </p>
-</section>
-
-
-<section id="section-Entailment">
-    <h3>Entailment</h3>
-
-    <p>The ideas on meaning and inference in RDF are underpinned by the
-    formal concept of <a href="http://www.w3.org/TR/2004/REC-rdf-mt-20040210/#entail">
-<cite>entailment</cite></a>, as 
-      discussed in the RDF
-    semantics document [[!RDF-MT]].
-In brief,  an RDF expression A is said to
-<dfn title="entailment">entail</dfn> another RDF&nbsp;expression B
-if every possible
-arrangement of things in the world that makes A true also makes B
-true. On this basis, if the truth of A is presumed or demonstrated
-then the truth of B can be inferred . 
-</p>
-</section>
-
-</section>
-
-
-<section id="section-URIspaces">
-    <h2>RDF Vocabulary IRI and Namespace</h2>
-
-    <p>RDF uses <a title="IRI">IRIs</a> to identify resources
-    and properties. Certain
-    IRIs are given specific meaning by RDF.  Specifically, IRIs
-    with the following leading substring are defined by the RDF
-    specifications:</p>
-
-    <ul>
-      <li><code>http://www.w3.org/1999/02/22-rdf-syntax-ns#</code>
-      (conventionally associated with namespace prefix <code>rdf:</code>)</li>
-<!--
-      <li><code>http://www.w3.org/2000/01/rdf-schema#</code>
-      (conventionally associated with namespace prefix <code>rdfs:</code>)</li>
--->
-    </ul>
-    <p>Used with the RDF/XML serialization, this IRI prefix
-    string corresponds to XML namespace names [[!XML-NAMES]] associated with the RDF
-    vocabulary terms.</p>
-
-    <p class="note">This namespace name is the same
-      as that used in the earlier RDF recommendation [[RDF-SYNTAX]].</p>
-
-    <p>Vocabulary terms in the <code>rdf:</code>
-    namespace are listed in <a
-    href="http://www.w3.org/TR/2004/REC-rdf-syntax-grammar-20040210/#section-Namespace">
-    section 5.1</a> of the RDF syntax specification [[!RDF-SYNTAX-GRAMMAR]]. Some of these terms are
-    defined by the RDF specifications to denote specific concepts.
-    Others have syntactic purpose (e.g. rdf:ID is part of
-    the RDF/XML syntax).</p>
-<!--
-    <p>Vocabulary terms defined in the <code>rdfs:</code> namespace are defined in the RDF
-    schema vocabulary specification [[RDF-SCHEMA]].</p>
--->
-</section>
-
-
-<section name="section-Datatypes">
-   <h2>Datatypes</h2>
-
-    <p class="issue">This section perhaps should discuss
-    <a href="http://www.w3.org/TR/rdf-mt/#dtype_interp">the XSD datatype map</a>
-    and <code><a href="http://www.w3.org/TR/rdf-plain-literal/">rdf:PlainLiteral</a></code>.</p>
-
-<p>
-The datatype abstraction used in RDF is compatible with 
-the abstraction used in
-XML Schema Part 2:
-    Datatypes [[!XMLSCHEMA-2]].</p>
-<p>
-A datatype consists of a lexical space, a value space and a lexical-to-value 
-mapping.
-</p>
-<p>The <dfn>lexical space</dfn> of a datatype is a set of Unicode [[!UNICODE]] strings.</p>
-<p>
-The <dfn>lexical-to-value mapping</dfn> of a datatype is a set of pairs whose 
-first element belongs to 
-the <a>lexical space</a> of the datatype, 
-and the second element belongs to the 
- <dfn>value space</dfn> of the datatype:
-</p>
-<ul>
-<li>
-Each member of the lexical space is paired with (maps to) exactly one member 
-of the value space.
-</li>
-<li>
-Each member of the value space may be paired with any number (including 
-zero) of members of the lexical space (lexical representations for that 
-value).
-</li>
-</ul>
-<p>
-A datatype is identified by one or more IRIs.
-</p>
-<p>
-RDF may be used with any datatype definition that conforms to this
-abstraction, even if not defined in terms of XML Schema.
-</p>
-   <p>Certain XML Schema built-in datatypes are not suitable for use 
-    within RDF. For example, the 
-<a href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#QName">QName</a> 
-datatype  requires a namespace declaration to be in scope during
-    the mapping, and is not recommended for use in RDF.
-    [[!RDF-MT]] contains a 
-<a href="http://www.w3.org/TR/2004/REC-rdf-mt-20040210/#dtype_interp">more detailed discussion</a>
- of specific XML Schema built-in datatypes. </p>
-
-<div class="note">
-<p>When the datatype is defined using XML Schema:
-</p>
-<ul>
-<li>
-All values correspond to some lexical form, either using
-the lexical-to-value mapping of the datatype or if it is a union
-datatype with a lexical mapping associated with one of the member
-datatypes.
-</li>
-<li>
-XML Schema facets remain part of the datatype and are used by the XML 
-Schema mechanisms that control the lexical space and the value space; 
-however, RDF does not define a standard mechanism to access these facets.</li>
-
-<li>In [[XMLSCHEMA-1]],
-<a href="http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#section-White-Space-Normalization-during-Validation">
-white space normalization</a> occurs
-during 
-<a href="http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#key-vn">validation</a> 
-according to the value of the 
-<a href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#rf-whiteSpace">whiteSpace
-facet</a>. The lexical-to-value mapping used in RDF datatyping
-occurs after this, so that the whiteSpace facet has no
-effect in RDF datatyping.
-</li>
-</ul>
-
-</div>
-
-
-<section id="section-XMLLiteral">
-    <h3>XML Content within an RDF Graph</h3>
-
-    <p class="issue">The canonicalization rules required for XML literals
-    are quite complicated. Increasingly, RDF is produced and consumed in
-    environments where no XML parser and canonicalization engine is
-    available. A possible change to relax the requirements for the
-    lexical space, while retaining the value space, is under discussion.
-    This is <a href="http://www.w3.org/2011/rdf-wg/track/issues/13">ISSUE-13</a>.</p>
-
-    <p>RDF provides for XML content as a possible literal value. This
-    typically originates from the use of
-    <code>rdf:parseType="Literal"</code> in the RDF/XML Syntax [[!RDF-SYNTAX-GRAMMAR]].</p>
-
-    <p>Such content is indicated in an RDF graph using a typed literal
-    whose datatype is a special built-in datatype
-    <dfn>rdf:XMLLiteral</dfn>,
-    defined as follows.</p>
-
-   
-    <dl>
-      <dt><a name="XMLLiteral-uri" id="XMLLiteral-uri">An IRI for
-identifying this datatype</a></dt>
-
-      <dd>is
-      <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>.</dd>
-
-      
- 
-
-      <dt><a name="XMLLiteral-lexical-space" id="XMLLiteral-lexical-space">The lexical space</a></dt>
-
-<dd>is the set of all
-strings:
-<ul>
-<li>which are well-balanced, self-contained 
-<a href="http://www.w3.org/TR/2000/REC-xml-20001006#NT-content">
-XML content</a> 
-[[!XML10]];
-</li>
-<li>for which encoding as UTF-8 
-[[!RFC2279]] yields 
-<a href="http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718/#def-exclusive-canonical-XML">
-exclusive
-Canonical XML </a> (with comments, with empty  
-<a href="http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718/#def-InclusiveNamespaces-PrefixList">
-InclusiveNamespaces PrefixList
-</a>) [[!XML-EXC-C14N]];
-</li>
-<li>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> [[!XML-NAMES]]</li>
-</ul>
-</dd>
-
-
-   <dt><a name="XMLLiteral-value-space" id="XMLLiteral-value-space">The value space</a></dt>
-
-      <dd>is a set of entities, called XML values, which is:
-<ul>
-<li>disjoint from the lexical space;</li>
-<li>disjoint from the value space of any other datatype that is not explicitly defined as a sub- or supertype of this datatype;</li>
-<li>disjoint from the set of Unicode character strings [[!UNICODE]];</li>
-<li>and in 1:1 correspondence with the lexical space.</li>
-</ul>
-</dd>
-
-      <dt><a name="XMLLiteral-mapping" id="XMLLiteral-mapping">The lexical-to-value mapping</a></dt>
-
-      <dd>
-is a one-one mapping from the lexical space onto the value space,
-    i.e. it is both injective and surjective.
-</dd> 
-
-
-
-    </dl>
-
-
-      <p class="note">Not all values of this datatype are compliant
-      with XML 1.1 [[XML11]]. If compliance
-      with XML 1.1 is desired, then only those values that are
-<a href="http://www.w3.org/TR/2002/CR-xml11-20021015/#sec2.13">fully
-      normalized</a> according to XML 1.1 should be used.</p>
-
-      <p class="note">XML values can be thought of as the 
-[[XML-INFOSET]] or the [[XPATH]]
-nodeset corresponding to the lexical form, with an appropriate equality
-function.</p>
-
-      <p class="note">RDF applications may use additional equivalence relations, such as
-that which relates an 
-<a href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#string"><code>xsd:string</code></a>
- 
-with an <code>rdf:XMLLiteral</code> corresponding to
-a single text node of the same string.</p>
-
-</section>
-
-</section>
-
-
-<section id="section-Graph-syntax">
-    <h2>Abstract Syntax</h2>
-
-    <p>This section defines the RDF abstract syntax. The RDF abstract
-    syntax is a set of triples, called the RDF graph.</p>
-
-    <p>This section also defines equivalence between RDF graphs. A
-    definition of equivalence is needed to support the RDF Test Cases
-    [[RDF-TESTCASES]] specification.</p>
-
-<p class="note">This <em>abstract</em> syntax is the
-syntax over which the formal semantics are defined.
-Implementations are free to represent RDF graphs in
-any other equivalent form.  As an example:
-in an RDF graph,
-literals with datatype <tt>rdf:XMLLiteral</tt> can be represented
-in a non-canonical
-format, and canonicalization performed during the comparison between two
-such literals. In this example the comparisons may be
-being performed either between syntactic structures or
-between their denotations in the domain of discourse.
-Implementations that do not require any such comparisons can
-hence be optimized.
-</p>
-
-    <p class="issue">The SPARQL WG proposed to add definitions for
-    “RDF Term” and “Simple Literal”.</p>
-
-
-<section id="section-triples">
-    <h3>RDF Triples</h3>
-
-    <p>An <dfn>RDF triple</dfn> contains three components:</p>
-
-    <ul>
-      <li>the <dfn>subject</dfn>, which is an
-      <a>IRI</a> or a <a>blank node</a></li>
-
-      <li>the <dfn>predicate</dfn>, which is an <a>IRI</a></li>
-
-      <li>the <dfn>object</dfn>, which is an <a>IRI</a>,
-      a <a>literal</a> or a <a>blank node</a></li>
-    </ul>
-
-    <p>An RDF triple is conventionally written in the order subject,
-    predicate, object.</p>
-    
-    <p>The predicate is also known as the <dfn>property</dfn> of the triple.</p>
-</section>
-
-
-<section id="section-rdf-graph">
-    <h3>RDF Graph</h3>
-
-    <p>An <dfn>RDF graph</dfn> is a set of RDF triples.</p>
-
-    <p>The set of <dfn title="node">nodes</dfn> of an RDF graph is the set of subjects and objects of
-    triples in the graph.</p>
-</section>
-
-    
-<section id="section-graph-equality">
-    <h3>Graph Equivalence</h3>
-
-    <p>Two <a title="RDF graph">RDF graphs</a> <var>G</var> and <var>G'</var> are equivalent 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">RDF literals</a> <var>lit</var> which
-      are nodes of <var>G</var>.</li>
-
-      <li><var>M(uri)=uri</var> for all <a title="IRI">IRIs</a> <var>uri</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>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>.</p>
-</section>
-    
-
-<section id="section-IRIs">
-    <h3>IRIs</h3>
-
-    <p>An <dfn title="IRI"><acronym title="Internationalized Resource Identifier">IRI</acronym></dfn>
-    (Internationalized Resource Identifier) within an RDF graph
-    is a Unicode string [[!UNICODE]] that conforms to the syntax
-    defined in RFC 3987 [[!IRI]]. IRIs are a generalization of
-    <dfn title="URI"><acronym title="Uniform Resource Identifier">URI</acronym>s</dfn>
-    [[URI]]. Every absolute URI and URL is an IRI.</p>
-
-    <p>IRIs in the RDF abstract syntax MUST be absolute, and MAY
-    contain a fragment identifier.</p>
-
-    <p>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 [[!IRI]]. Further normalization MUST NOT be performed when
-    comparing IRIs for equality.</p>
-
-    <p class="note">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 [[!IRI]]. 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 class="note">Some concrete syntaxes permit relative IRIs
-    as a shorthand for absolute IRIs, and define how to resolve
-    the relative IRIs against a base IRI.</p>
-
-    <p class="note">Previous versions of RDF used the term
-    “<dfn>RDF URI Reference</dfn>” instead of “IRI” and allowed
-    additional characters:
-    “<code>&lt;</code>”, “<code>&gt;</code>”,
-    “<code>{</code>”, “<code>}</code>”,
-    “<code>|</code>”, “<code>\</code>”,
-    “<code>^</code>”, “<code>`</code>”,
-    ‘<code>“</code>’ (double quote), and “<code> </code>” (space).
-    In IRIs, these characters must be percent-encoded as
-    described in <a href="http://tools.ietf.org/html/rfc3986#section-2.1">section 2.1</a>
-    of [[URI]].</p>
-
-    <div class="note">
-      <p>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 [[!IRI]]. Non-normalized forms that should be 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 IRI syntax</li>
-        <li>Explicitly stated HTTP default port
-          (<code>http://example.com:80/</code>);
-          <code>http://example.com/</code> is preferrable</li>
-        <li>Completely empty path in HTTP IRIs
-          (<code>http://example.com</code>);
-          <code>http://example.com/</code> is preferrable</li>
-        <li>“<code>/./</code>” or “<code>/../</code>” in the path
-          component of an IRI</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 [[!NFC]]</li>
-      </ul>
-    </div>
-</section>
-
-
-<section id="section-Graph-Literal">
-    <h3>RDF Literals</h3>
-
-    <p class="issue">Currently, there are three different
-    kinds of literals for expressing strings: plain literals,
-    <a href=""><code>rdf:PlainLiteral</code></a> [[RDF-PLAINLITERAL]],
-    and <code>xsd:string</code>. Some consolidation of these
-    forms is under consideration. This is
-    <a href="http://www.w3.org/2011/rdf-wg/track/issues/12">ISSUE-12</a>.</p>
-
-<p>A <dfn>literal</dfn> in an <a>RDF graph</a>
-contains one or two named components.</p>
-<p>All literals have a <dfn>lexical form</dfn> being a Unicode
-[[!UNICODE]] string, which SHOULD be in Normal Form C [[!NFC]].</p>
-
-
-    <p><dfn title="plain literal">Plain literals</dfn> have 
-    a <a>lexical form</a> and optionally a <dfn>language tag</dfn> as
-    defined by [[!BCP47]]. The language tag, if present, MUST be
-    well-formed according to
-    <a href="http://tools.ietf.org/html/rfc5646#section-2.2.9">section 2.2.9</a>
-    of [[!BCP47]], and MUST be normalized to lowercase.</p>
-
-    <p><dfn title="typed literal">Typed literals</dfn> have a <a>lexical form</a>
-    and a <dfn>datatype IRI</dfn> being an <a>IRI</a>.</p>
- 
-
-      <p class="note">Literals in which the lexical form begins with a
-      composing character (as defined by [[CHARMOD]]) are allowed however they may cause
-      interoperability problems, particularly with XML version 1.1 [[XML11]].</p>
-
-    <p class="note">Earlier versions of RDF permitted tags that
-    adhered to the generic tag/subtag syntax of language tags,
-    but were not well-formed according to [[!BCP47]]. Such
-    language tags do not conform to RDF 1.1.</p>
-
-      <p class="note">When using the language tag, care must be
-      taken not to confuse language with locale. The language
-      tag relates only to human language text. Presentational
-      issues should
-      be addressed in end-user applications.</p>
-
-      <p class="note">The case normalization of 
-language tags is part of
- the description of the abstract syntax, and consequently the abstract
- behaviour of RDF applications. It does not constrain an
- RDF implementation to actually normalize the case. Crucially, the result
- of comparing two language tags should not be sensitive to the case of
- the original input.</p>
-
-
-<section id="section-Literal-Equality">
-    <h4>Literal Equality</h4>
-
-    <p>Two literals are equal if and only if all of the following
-    hold:</p>
-
-    <ul>
-      <li>The strings of the two lexical forms compare equal, character
-      by character.</li>
-
-      <li>Either both or neither have language tags.</li>
-
-      <li>The language tags, if any, compare
-      equal.</li>
-
-      <li>Either both or neither have datatype IRIs.</li>
-
-      <li>The two datatype IRIs, if any, compare equal, character by
-      character.</li>
-    </ul>
-
-      <p class="note">RDF Literals are distinct and distinguishable
-      from <a title="IRI">IRIs</a>; e.g. <code>http://example.org/</code> as an RDF
-      Literal (untyped, without a language tag) is not equal to
-      <code>http://example.org/</code> as an IRI.</p>
-</section>
-
-
-<section id="section-Literal-Value">
-    <h4>The Value Corresponding to a Typed Literal</h4>
-
-    <p>The datatype IRI refers to a <a href=
-    "#section-Datatypes">datatype</a>. For XML Schema <a href=
-    "http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#built-in-datatypes">
-    built-in</a> datatypes, IRIs such as
-    <code>http://www.w3.org/2001/XMLSchema#int</code> are used. The IRI
-    of the datatype <a href="#section-XMLLiteral"><tt>rdf:XMLLiteral</tt></a> may be used.
-    There may be other, implementation dependent, mechanisms by which
-    IRIs refer to datatypes.</p>
-
-    <p>The <em>value</em> associated with a typed literal is found by
-    applying the lexical-to-value mapping associated with the datatype IRI to
-    the lexical form.
-    </p>
-
-    <p>
- If the lexical form is not in
-    the lexical space of the datatype associated with the datatype IRI,
-then no literal value can be associated with the typed literal.
-Such a case, while in error, is not  <em>syntactically</em> ill-formed.</p>
-<!--
-    <p>A typed literal for which the datatype does not map the lexical
-    form to a value is not syntactically ill-formed.</p>
--->
-    
-
-      <p class="note">
-In application contexts, comparing the values of typed literals (see 
-<a href="#section-Literal-Value">
-section
-6.5.2</a>)
-is usually more helpful than comparing their syntactic forms (see 
-<a href="#section-Literal-Equality">
-section
-6.5.1</a>).
-Similarly, for comparing RDF Graphs,
-semantic notions of entailment (see 
-[[!RDF-MT]]) are usually
-more helpful than syntactic equality (see 
-<a href="#section-graph-equality">
-section
-6.3</a>).</p>
-
-</section>
-
-</section>
-
-
-<section id="section-blank-nodes">
-   <h3>Blank Nodes</h3>
-
-<p>
-The <dfn title="blank node">blank nodes</dfn> in an RDF graph 
-are drawn from an infinite set.
-This set of blank nodes, the set of all <a title="IRI">IRIs</a>
-and the set of all <a title="literal">literals</a> are pairwise disjoint.
-</p>
-<p>
-Otherwise, this set of blank nodes is arbitrary.
-</p>
-<p>RDF makes no reference to any internal structure of blank nodes.
-Given two blank nodes, it is 
-possible to determine whether or not they are the same.</p>
-
-
-<section id="section-skolemization">
-    <h4>Replacing Blank Nodes with IRIs</h4>
-
-    <p>Blank nodes do not have identifiers in the RDF abstract syntax. The
-    <a title="blank node identifier">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 MAY
-    systematically transform some or all of the blank nodes in an RDF graph
-    into IRIs [[!IRI]].  Systems wishing to do this SHOULD mint a new, globally
-    unique IRI (a <dfn>Skolem IRI</dfn>) for each blank node so transformed.</p>
-
-    <p>This transformation does not change the meaning of an RDF graph,
-    provided that the Skolem IRIs do not occur anywhere else.</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 a blank
-    node, and map back to the source blank node where possible.</p>
-
-    <p>Systems that want Skolem IRIs to be recognizable outside of the system
-    boundaries SHOULD use a well-known IRI [[WELL-KNOWN]] with the registered
-    name <code>genid</code>. This is an IRI 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>For example, the authority responsible for the domain
-    <code>example.com</code> could mint the following recognizable Skolem IRI:</p>
-
-    <pre>http://example.com/.well-known/genid/d26a2d0e98334696f4ad70a677abc1f6</pre>
-
-    <p class="issue">IETF registration of the <code>genid</code> name is
-    currently in progress.</p>
-
-    <p class="note">RFC 5785 [[WELL-KNOWN]] only specifies well-known URIs,
-    not IRIs. For the purpose of this document, a well-known IRI is any
-    IRI that results in a well-known URI after IRI-to-URI mapping [[!IRI]].</p>
-</section>
-
-</section>
-
-
-<section id="section-multigraph">
-    <h2>Abstract Syntax for Working with Multiple Graphs</h2>
-
-    <div class="issue">
-        <p>The Working Group will standardize a model and semantics for
-        multiple graphs and graphs stores. The
-        <a href="http://www.w3.org/2011/01/rdf-wg-charter">charter</a> notes:</p>
-
-        <blockquote>The RDF Community has used the
-        term “named graphs” for a number of years in various settings,
-        but this term is ambiguous, and often refers to what could rather
-        be referred as quoted graphs, graph literals, IRIs for graphs,
-        knowledge bases, graph stores, etc. The term “Support for Multiple
-        Graphs and Graph Stores” is used as a neutral term in this charter;
-        this term is not and should not be considered as definitive.
-        The Working Group will have to define the right term(s).</blockquote>
-
-        <p>Progress on the design for this feature is tracked under multiple
-        issues:</p>
-
-        <ul>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/5">ISSUE-5: Should we define Graph Literal datatypes?</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/14">ISSUE-14: What is a named graph and what should we call it?</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/15">ISSUE-15: What is the relationship between the IRI and the triples in a dataset/quad-syntax/etc</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/17">ISSUE-17: How are RDF datasets to be merged?</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/22">ISSUE-22: Does multigraph syntax need to support empty graphs?</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/28">ISSUE-28: Do we need syntactic nesting of graphs (g-texts) as in N3?</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/29">ISSUE-29: Do we support SPARQL's notion of "default graph"?</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/30">ISSUE-30: How does SPARQL's notion of RDF dataset relate our notion of multiple graphs?</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/32">ISSUE-32: Can we identify both g-boxes and g-snaps?</a></li>
-            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/33">ISSUE-33: Do we provide a way to refer to sub-graphs and/or individual triples?</a></li>
-        </ul>
-    </div>
-</section>
-
-</section>
-
-
-<section id="section-fragID" class="informative">
-    <h2>Fragment Identifiers</h2>
-
-    <p class="issue">This section does not address the case where RDF is
-    embedded in other document formats, such as in RDFa or when an RDF/XML
-    fragment is embedded in SVG. It has been suggested that this may be
-    a general issue for the TAG about the treatment of
-    fragment identifiers when one language is embedded in another. This is
-    <a href="http://www.w3.org/2011/rdf-wg/track/issues/37">ISSUE-37</a>.</p>
-
-    <p class="issue">This section requires updates to address the
-    change from <a title="RDF URI Reference">URI References</a> to <a title="IRI">IRIs</a>.</p>
-
-    <p>RDF uses an <a title="RDF URI Reference">RDF URI
-    Reference</a>, which may include a fragment identifier, as a
-    context free identifier for a resource. RFC 2396 states that the meaning of a fragment
-    identifier depends on the MIME content-type of a document, i.e.
-    is context dependent.</p>
-    <p>These apparently conflicting views are reconciled by
-    considering that a URI reference in an RDF graph is treated
-    with respect to the MIME type <code>application/rdf+xml</code>
-    [[!RDF-MIME-TYPE]]. Given an RDF URI
-    reference consisting of an absolute URI and a fragment
-    identifier, the fragment identifer identifies the same thing
-    that it does in an <code>application/rdf+xml</code> representation of the
-    resource identified by the absolute URI component. Thus:</p>
-    <ul>
-      <li>we assume that the URI part (i.e. excluding fragment
-      identifier) identifies a resource, which is presumed to have
-      an RDF representation. So when <code>eg:someurl#frag</code> is used in an RDF
-      document, <code>eg:someurl</code> is taken to
-      designate some RDF document (even when no such document can
-      be retrieved).</li>
-      <li><code>eg:someurl#frag</code> means the thing
-      that is indicated, according to the rules of the
-      <code>application/rdf+xml</code> MIME content-type as
-      a “fragment” or “view” of the RDF document at
-      <code>eg:someurl</code>. If the document does not
-      exist, or cannot be retrieved, or is available only in
-      formats other than <code>application/rdf+xml</code>, then exactly what
-      that view may be is somewhat undetermined, but that does not
-      prevent use of RDF to say things about it.</li>
-      <li>the RDF treatment of a fragment identifier allows it to
-      indicate a thing that is entirely external to the document,
-      or even to the “shared information space” known as the Web.
-      That is, it can be a more general idea, like some particular
-      car or a mythical Unicorn.</li>
-      <li>in this way, an <code>application/rdf+xml</code> document acts as an
-      intermediary between some Web retrievable documents (itself,
-      at least, also any other Web retrievable URIs that it may
-      use, possibly including schema URIs and references to other
-      RDF documents), and some set of possibly abstract or non-Web
-      entities that the RDF may describe.</li>
-    </ul>
-    <p>This provides a handling of URI references and their
-    denotation that is consistent with the RDF model theory and
-    usage, and also with conventional Web behavior. Note that
-    nothing here requires that an RDF application be able to
-    retrieve any representation of resources identified by the URIs
-    in an RDF graph.</p>
-</section>
-
-
-<section id="section-Acknowledgments" class="informative">
-    <h2>Acknowledgments</h2>
-
-    <p class="issue">This section does not yet list those who made
-    contributions to the RDF 1.1 version, nor does it list the
-    current RDF WG members.</p>
-
-    <p>This document contains a significant contribution from Pat
-    Hayes, Sergey Melnik and Patrick Stickler, under whose leadership
-    was developed the framework described in the RDF family of
-    specifications for representing datatyped values, such as integers
-    and dates.</p>
-
-    <p>The editors acknowledge valuable contributions from the
-    following: <!--</p>
-
-    <ul>-->
-      <!--<li>-->Frank Manola, <!--</li>-->
-
-      <!--<li>-->Pat Hayes, <!--</li>-->
-
-      <!--<li>-->Dan Brickley, <!--</li>-->
-
-      <!--<li>-->Jos de Roo, <!--</li>-->
-
-      <!--<li>-->Dave Beckett, <!--</li>-->
-
-      <!--<li>-->Patrick Stickler, <!--</li>-->
-
-      <!--<li>-->Peter F. Patel-Schneider, <!--</li>-->
-
-      <!--<li>-->Jerome Euzenat, <!--</li>-->
-
-      <!--<li>-->Massimo Marchiori, <!--</li>-->
-
-      <!--<li>-->Tim Berners-Lee, <!--</li>-->
-
-      <!--<li>-->Dave Reynolds <!--</li>-->
-
-      <!--<li>-->and Dan Connolly. <!--</li>-->
-<!--
-      <li class="todo">[[[Other contributors]]]</li>
-    </ul>
--->
-</p>
-    <p>Jeremy Carroll thanks <a href="mailto:[email protected]">Oreste
-    Signore</a>, his host at the <a href="http://www.w3c.it/">W3C
-    Office in Italy</a> and <a href="http://www.isti.cnr.it" lang="it"
-    xml:lang="it">Istituto di Scienza e Tecnologie dell'Informazione
-    “Alessandro Faedo”</a>, part of the <a href="http://www.cnr.it"
-    lang="it" xml:lang="it">Consiglio Nazionale delle Ricerche</a>,
-    where Jeremy is a visiting researcher.</p>
-
-    <p>This document is a product of extended deliberations by the
-    RDFcore Working Group, whose members have included:
-
-<!--</p><ul>-->
-      <!--<li>-->Art Barstow (W3C), <!--</li>-->
-
-      <!--<li>-->Dave Beckett (ILRT), <!--</li>-->
-
-      <!--<li>-->Dan Brickley (ILRT), <!--</li>-->
-
-      <!--<li>-->Dan Connolly (W3C), <!--</li>-->
-
-      <!--<li>-->Jeremy Carroll (Hewlett Packard), <!--</li>-->
-
-      <!--<li>-->Ron Daniel (Interwoven Inc), <!--</li>-->
-
-      <!--<li>-->Bill dehOra (InterX), <!--</li>-->
-
-      <!--<li>-->Jos De Roo (AGFA), <!--</li>-->
-
-      <!--<li>-->Jan Grant (ILRT), <!--</li>-->
-
-      <!--<li>-->Graham Klyne (Nine by Nine), <!--</li>-->
-
-      <!--<li>-->Frank Manola (MITRE Corporation), <!--</li>-->
-
-      <!--<li>-->Brian McBride (Hewlett Packard), <!--</li>-->
-
-      <!--<li>-->Eric Miller (W3C), <!--</li>-->
-
-      <!--<li>-->Stephen Petschulat (IBM), <!--</li>-->
-
-      <!--<li>-->Patrick Stickler (Nokia), <!--</li>-->
-
-      <!--<li>-->Aaron Swartz (HWG), <!--</li>-->
-
-      <!--<li>-->Mike Dean (BBN Technologies / Verizon), <!--</li>-->
-
-      <!--<li>-->R. V. Guha (Alpiri Inc), <!--</li>-->
-
-      <!--<li>-->Pat Hayes (IHMC), <!--</li>-->
-
-      <!--<li>-->Sergey Melnik (Stanford University) and <!--</li>-->
-
-      <!--<li>-->Martyn Horner (Profium Ltd). <!--</li>-->
-    </p> <!--</ul>-->
-    <p>This specification also draws upon an earlier RDF Model and
-    Syntax document edited by Ora Lassilla and Ralph Swick, and RDF
-    Schema edited by Dan Brickley and R. V. Guha. RDF and RDF Schema
-    Working Group members who contributed to this earlier work are:
-
-     <!--</p><ul>-->
-      <!--<li>-->Nick Arnett (Verity), <!--</li>-->
-
-      <!--<li>-->Tim Berners-Lee (W3C), <!--</li>-->
-
-      <!--<li>-->Tim Bray (Textuality), <!--</li>-->
-
-      <!--<li>-->Dan Brickley (ILRT / University of Bristol), <!--</li>-->
-
-      <!--<li>-->Walter Chang (Adobe), <!--</li>-->
-
-      <!--<li>-->Sailesh Chutani (Oracle), <!--</li>-->
-
-      <!--<li>-->Dan Connolly (W3C), <!--</li>-->
-
-      <!--<li>-->Ron Daniel (DATAFUSION), <!--</li>-->
-
-      <!--<li>-->Charles Frankston (Microsoft), <!--</li>-->
-
-      <!--<li>-->Patrick Gannon (CommerceNet), <!--</li>-->
-
-      <!--<li>-->R. V. Guha (Epinions, previously of Netscape
-      Communications), <!--</li>-->
-
-      <!--<li>-->Tom Hill (Apple Computer), <!--</li>-->
-
-      <!--<li>-->Arthur van Hoff (Marimba), <!--</li>-->
-
-      <!--<li>-->Renato Iannella (DSTC), <!--</li>-->
-
-      <!--<li>-->Sandeep Jain (Oracle), <!--</li>-->
-
-      <!--<li>-->Kevin Jones, (InterMind), <!--</li>-->
-
-      <!--<li>-->Emiko Kezuka (Digital Vision Laboratories), <!--</li>-->
-
-      <!--<li>-->Joe Lapp (webMethods Inc.), <!--</li>-->
-
-      <!--<li>-->Ora Lassila (Nokia Research Center), <!--</li>-->
-
-      <!--<li>-->Andrew Layman (Microsoft), <!--</li>-->
-
-      <!--<li>-->Ralph LeVan (OCLC), <!--</li>-->
-
-      <!--<li>-->John McCarthy (Lawrence Berkeley National Laboratory), <!--</li>-->
-
-      <!--<li>-->Chris McConnell (Microsoft), <!--</li>-->
-
-      <!--<li>-->Murray Maloney (Grif), <!--</li>-->
-
-      <!--<li>-->Michael Mealling (Network Solutions), <!--</li>-->
-
-      <!--<li>-->Norbert Mikula (DataChannel), <!--</li>-->
-
-      <!--<li>-->Eric Miller (OCLC), <!--</li>-->
-
-      <!--<li>-->Jim Miller (W3C, emeritus), <!--</li>-->
-
-      <!--<li>-->Frank Olken (Lawrence Berkeley National Laboratory), <!--</li>-->
-
-      <!--<li>-->Jean Paoli (Microsoft), <!--</li>-->
-
-      <!--<li>-->Sri Raghavan (Digital/Compaq), <!--</li>-->
-
-      <!--<li>-->Lisa Rein (webMethods Inc.), <!--</li>-->
-
-      <!--<li>-->Paul Resnick (University of Michigan), <!--</li>-->
-
-      <!--<li>-->Bill Roberts (KnowledgeCite), <!--</li>-->
-
-      <!--<li>-->Tsuyoshi Sakata (Digital Vision Laboratories), <!--</li>-->
-
-      <!--<li>-->Bob Schloss (IBM), <!--</li>-->
-
-      <!--<li>-->Leon Shklar (Pencom Web Works), <!--</li>-->
-
-      <!--<li>-->David Singer (IBM), <!--</li>-->
-
-      <!--<li>-->Wei (William) Song (SISU), <!--</li>-->
-
-      <!--<li>-->Neel Sundaresan (IBM), <!--</li>-->
-
-      <!--<li>-->Ralph Swick (W3C), <!--</li>-->
-
-      <!--<li>-->Naohiko Uramoto (IBM), <!--</li>-->
-
-      <!--<li>-->Charles Wicksteed (Reuters Ltd.), <!--</li>-->
-
-      <!--<li>-->Misha Wolf (Reuters Ltd.) and <!--</li>-->
-
-      <!--<li>-->Lauren Wood (SoftQuad). <!--</li>-->
-    <!--</ul>--></p>
-</section>
-
-
-<section class="appendix informative" id="changes">
-  <h2>Changes from RDF 2004</h2>
-
-  <ul>
-    <li>2011-06-01: Replaced the URI References section with <a href="#section-IRIs">new section on IRIs</a>, and changed “RDF URI Reference” to “IRI” throughout the document, except in <a href="#section-fragID">section 8</a>.</li>
-    <li>2011-06-01: Changed language tag definition to require well-formedness according to BCP47; added a note that this invalidates some RDF</li>
-    <li>2011-05-25: Added boxes for known WG issues throught the document</li>
-    <li>2011-05-25: Deleted “Structure of this Document” section, it added no value beyond the TOC</li>
-    <li>2011-05-25: Implemented resolution of <a href="http://www.w3.org/2011/rdf-wg/track/issues/40">ISSUE-40: Skolemization advice in the RDF dcocument</a> by adding a section on <a href="#section-skolemization">Replacing Blank Nodes with IRIs</a></li>
-    <li>2011-05-25: rdf:XMLLiteral is disjoint from any datatype not explicitly related to it, per erratum <a href="http://www.w3.org/2001/sw/RDFCore/errata#concept-xmlliteral">[concept-xmlliteral]</a></li>
-    <li>2011-05-25: Added Conformance section with RFC2119 reference</li>
-    <li>2011-05-25: Updated all W3C references to latest editions, and Unicode from v3 to v4</li>
-    <li>2011-05-24: Converted to ReSpec, changed metadata to reflect RDF 1.1</li>
-  </ul>
-</section>
-
-
-<section id="references">
-    <div class="issue">
-      <ul>
-        <li>RFC 2279 is obsoleted by RFC 3629</li>
-        <li>Change OWL reference to OWL2?</li>
-        <li>Change XHTML10 reference to XHTML5?</li>
-      </ul>
-    </div>
-</section>
-
-  </body>
-</html>
-
Binary file rdf-concepts/Graph-ex.gif has changed
Binary file rdf-concepts/fig6may19 has changed
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rdf-concepts/index.html	Wed Jun 01 19:12:07 2011 +0100
@@ -0,0 +1,1563 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+    <title>RDF 1.1 Concepts and Abstract Syntax</title>
+    <style>
+.figure { font-weight: bold; text-align: center; }
+    </style>
+    <script src='../ReSpec.js/js/respec.js' class='remove'></script>
+    <script class='remove'>
+      var respecConfig = {
+          // specification status (e.g. WD, LCWD, NOTE, etc.). If in doubt use ED.
+          specStatus:           "ED",
+          
+          // the specification's short name, as in http://www.w3.org/TR/short-name/
+          shortName:            "rdf11-concepts",
+
+          // if your specification has a subtitle that goes below the main
+          // formal title, define it here
+          // subtitle   :  "an excellent document",
+
+          // if you wish the publication date to be other than today, set this
+          // publishDate:  "2009-08-06",
+
+          // if the specification's copyright date is a range of years, specify
+          // the start date here:
+          copyrightStart: "2004",
+
+          // if there is a previously published draft, uncomment this and set its YYYY-MM-DD date
+          // and its maturity status
+//          previousPublishDate:  "2004-02-10",
+//          previousMaturity:  "REC",
+
+          // if there a publicly available Editor's Draft, this is the link
+//@@@
+          edDraftURI:           "http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html",
+
+          // if this is a LCWD, uncomment and set the end of its review period
+          // lcEnd: "2009-08-05",
+
+          // if there is an earler version of this specification at the Recommendation level,
+          // set this to the shortname of that version. This is optional and not usually
+          // necessary.
+          prevRecShortname: "rdf-concepts",
+
+          // if you want to have extra CSS, append them to this list
+          // it is recommended that the respec.css stylesheet be kept
+          extraCSS:             ["http://dev.w3.org/2009/dap/ReSpec.js/css/respec.css"],
+
+          // editors, add as many as you like
+          // only "name" is required
+          editors:  [
+              { name: "Richard Cyganiak", url: "http://richard.cyganiak.de/",
+                company: "DERI, NUI Galway", companyURL: "http://www.deri.ie/",
+              },
+// @@@ Details for David?
+              { name: "David Wood", // url: "http://example.org/",
+                company: "Talis", companyURL: "http://www.talis.com/",
+              },
+          ],
+          otherContributors: {
+              "Previous editor": [
+// @@@ Graham's affiliation has changed
+                  { name: "Graham Klyne",
+                    url: "http://www.ninebynine.org/",
+                    company: "Nine by Nine",
+                    //companyURL: "http://example.com/"
+                    //mailto: "[email protected]",
+                  },
+// @@@ Jeremy's affiliation has changed
+                  { name: "Jeremy J. Carroll",
+                    //url: "http://www-uk.hpl.hp.com/people/jjc/",
+                    company: "Hewlett Packard Labs",
+                    //companyURL: "http://example.com/"
+                    //mailto: "[email protected]",
+                  },
+// @@@ Brian's affiliation has changed
+                  { name: "Brian McBride",
+                    //url: "http://www-uk.hpl.hp.com/people/bwm/",
+                    company: "Hewlett Packard Labs",
+                    //companyURL: "http://example.com/"
+                    //mailto: "[email protected]",
+                    note: "RDF 2004 Series Editor",
+                  },
+              ],
+          },
+
+          // authors, add as many as you like. 
+          // This is optional, uncomment if you have authors as well as editors.
+          // only "name" is required. Same format as editors.
+
+          //authors:  [
+          //    { name: "Your Name", url: "http://example.org/",
+          //      company: "Your Company", companyURL: "http://example.com/" },
+          //],
+          
+          // name of the WG
+          wg:           "RDF Working Group",
+          
+          // URI of the public WG page
+          wgURI:        "http://www.w3.org/2011/rdf-wg/",
+          
+          // name (with the @w3c.org) of the public mailing to which comments are due
+          wgPublicList: "public-rdf-comments",
+          
+          // URI of the patent status for this WG, for Rec-track documents
+          // !!!! IMPORTANT !!!!
+          // This is important for Rec-track documents, do not copy a patent URI from a random
+          // document unless you know what you're doing. If in doubt ask your friendly neighbourhood
+          // Team Contact.
+          wgPatentURI:  "http://www.w3.org/2004/01/pp-impl/46168/status",
+
+          // if this parameter is set to true, ReSpec.js will embed various RDFa attributes
+          // throughout the generated specification. The triples generated use vocabulary items
+          // from the dcterms, foaf, and bibo. The parameter defaults to false.
+          doRDFa: true,
+      };
+
+// @@@ A number of references have been patched into the local berjon.biblio and need to be added to the global biblio in CVS:
+    </script>
+  </head>
+
+  <body>
+
+<section id="abstract">
+    <p>The Resource Description Framework (RDF) is a framework for
+    representing information in the Web.</p>
+    <p>RDF Concepts and Abstract Syntax defines an abstract syntax
+    on which RDF is based, and which serves to link its concrete
+    syntax to its formal semantics. It also includes discussion of
+    design goals, key concepts, datatyping, character normalization
+    and handling of IRIs.</p>
+</section>
+
+
+<section id="section-Introduction">
+    <h2>Introduction</h2>
+
+    <p class="issue">This document reflects current progress of the RDF Working
+      Group towards updating the
+      <a href="http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/">2004
+      version of <em>RDF Concepts and Abstract Syntax</em></a>. The
+      editors expect to work on a number of issues, some of which are
+      listed in boxes like this throughout the document.</p>
+
+    <p>The Resource Description Framework (RDF) is a framework for
+    representing information in the Web.</p>
+
+    <p>This document defines an abstract syntax on which RDF is based,
+    and which serves to link its concrete syntax to its formal
+    semantics. 
+This abstract syntax is quite distinct from XML's tree-based infoset
+    [[XML-INFOSET]]. It also includes discussion of design goals, 
+    key concepts, datatyping, character normalization
+    and handling of IRIs.</p>
+
+    <p>Normative documentation of RDF falls into the following
+    areas:</p>
+
+    <ul>
+      <li>XML serialization syntax [[!RDF-SYNTAX-GRAMMAR]],</li>
+
+      <li>formal semantics [[!RDF-MT]], and</li>
+
+      <li>this document (sections 4, 5, 6 and 7).</li>
+    </ul>
+
+    <p class="issue">This document was written when RDF/XML was the
+    only normative syntax. Now it is just one of many syntaxes and
+    it should be de-emphasized accordingly. There is no reason why
+    it should be a normative reference in this document.</p>
+
+    <p>The framework is designed so that vocabularies can be layered.  
+The RDF and RDF vocabulary definition (RDF schema) 
+languages 
+    [[RDF-SCHEMA]] are the first
+    such vocabularies.
+ 
+    Others (cf. OWL [[OWL-REF]] and
+    the applications mentioned in the primer 
+    [[RDF-PRIMER]]) are in development.</p>
+</section>
+
+
+<section id="conformance"></section>
+
+
+<section id="section-Overview" class="informative">
+    <h2>Motivations and Goals</h2>
+
+    <p class="issue">Does this section add value?</p>
+
+    <p>RDF has an abstract syntax that reflects a simple graph-based
+    data model, and formal semantics with a rigorously defined notion
+    of entailment providing a basis for well founded deductions in RDF
+    data.</p>
+
+<section id="section-motivation">
+    <h3>Motivation</h3>
+
+    <p>The development of RDF has been motivated by the following uses,
+    among others:</p>
+
+    <ul>
+      <li>Web metadata: providing information about Web resources and
+      the systems that use them (e.g. content rating, capability
+      descriptions, privacy preferences, etc.)</li>
+
+      <li>Applications that require open rather than constrained
+      information models (e.g. scheduling activities, describing
+      organizational processes, annotation of Web resources, etc.)</li>
+
+      <li>To do for machine processable information (application data)
+      what the World Wide Web has done for hypertext: to allow data to
+      be processed outside the particular environment in which it was
+      created, in a fashion that can work at Internet scale.</li>
+
+      <li>Interworking among applications: combining data from several
+      applications to arrive at new information.</li>
+
+      <li>Automated processing of Web information by software agents:
+      the Web is moving from having just human-readable information to
+      being a world-wide network of cooperating processes. RDF provides
+      a world-wide lingua franca for these processes.</li>
+    </ul>
+
+    <p>RDF is designed to represent information in a minimally
+    constraining, flexible way. It can be used in isolated
+    applications, where individually designed formats 
+    might be more direct and easily understood,  but RDF's generality offers greater value from
+    sharing. The value of information thus increases as it becomes
+    accessible to more applications across the entire Internet.</p>
+</section>
+
+
+<section>
+    <h3 id="section-design-goals">Design Goals</h3>
+
+    <p>The design of RDF is intended to meet the following goals:</p>
+
+    <ul>
+      <li>having a simple data model</li>
+      <li>having formal semantics and provable inference</li>
+      <li>using an extensible IRI-based vocabulary</li>
+      <li>using an XML-based syntax</li>
+      <li>supporting use of XML schema datatypes</li>
+      <li>allowing anyone to make statements about any
+      resource</li>
+   </ul>
+
+
+<section id="section-simple-data-model">
+    <h4>A Simple Data Model</h4>
+
+    <p>RDF has a simple data model that is easy for applications to
+    process and manipulate. The data model is independent of any
+    specific serialization syntax.</p>
+
+      <p class="note">The term “model” used here in “data model” has a
+      completely different sense to its use in the term “model theory”.
+      See  [[!RDF-MT]] 
+      for more information about “model theory” as used in the literature of mathematics and logic.</p>
+</section>
+
+
+<section id="section-formal-semantics">
+    <h4>Formal Semantics and Inference</h4>
+
+    <p>RDF has a formal semantics which provides a dependable basis for
+    reasoning about the meaning of an RDF expression. In particular, it
+    supports rigorously defined notions of entailment which provide a
+    basis for defining reliable rules of inference in RDF data.</p>
+</section>
+
+
+<section id="section-extensible-vocab">
+    <h4>Extensible IRI-based Vocabulary</h4>
+
+    <p>The vocabulary is fully extensible, being based on IRIs.
+    IRIs are used for naming all kinds of things in RDF.</p>
+
+    <p>The other kind of value that appears in RDF data is a
+    literal.</p>
+</section>
+
+
+<section id="section-xml-serialization">
+    <h4>XML-based Syntax</h4>
+
+    <p>RDF has a recommended XML serialization form [[!RDF-SYNTAX-GRAMMAR]], which can be used to encode the
+    data model for exchange of information among applications.</p>
+</section>
+
+
+<section id="section-use-xsd">
+    <h4>Use XML Schema Datatypes</h4>
+
+    <p>RDF can use values represented according to XML schema datatypes
+    [[!XMLSCHEMA-2]], thus assisting the
+    exchange of information between RDF and other XML applications.</p>
+</section>
+
+
+<section id="section-anyone">
+    <h4>Anyone Can Make Statements About Any Resource</h4>
+
+    <p>To facilitate operation at Internet scale, RDF is an
+    open-world framework that allows anyone to make statements
+    about any resource.</p>
+    <p>In general, it is not assumed that complete information
+    about any resource is available. RDF does not prevent anyone
+    from making assertions that are nonsensical or inconsistent
+    with other statements, or the world as people see it. Designers
+    of applications that use RDF should be aware of this and may
+    design their applications to tolerate incomplete or
+    inconsistent sources of information.</p>
+</section>
+
+</section>
+
+</section>
+
+
+<section id="section-Concepts" class="informative">
+    <h2>RDF Concepts</h2>
+
+    <p class="issue">This section is quite redundant with later normative sections and the RDF Primer.</p>
+
+    <p>RDF uses the following key concepts:</p>
+
+    <ul>
+      <li>Graph data model</li>
+
+      <li>IRI-based vocabulary</li>
+
+      <li>Datatypes</li>
+
+      <li>Literals</li>
+
+      <li>XML serialization syntax</li>
+
+      <li>Expression of simple facts</li>
+
+      <li>Entailment</li>
+    </ul>
+
+
+<section id="section-data-model">
+    <h3>Graph Data Model</h3>
+
+    <p>The underlying structure of any expression in RDF is a
+    collection of triples, each consisting of a subject, a
+    predicate and an object. A set of such triples is called an RDF
+    graph (defined more formally in 
+<a href="#section-Graph-syntax">section 6</a>). This can be
+    illustrated by a node and directed-arc diagram, in which each
+    triple is represented as a node-arc-node link (hence the term
+    “graph”).</p>
+
+    <div class="figure">
+      <img src="Graph-ex.gif" alt="image of the RDF triple comprising (subject, predicate, object)" />
+    </div>
+
+    <p>Each triple represents a statement of a relationship between
+    the things denoted by the nodes that it links. Each triple has
+    three parts:</p>
+    <ol>
+      <li>a <a>subject</a>,</li>
+      <li>an <a>object</a>, and</li>
+      <li>a <a>predicate</a> (also called a
+      <a>property</a>) that denotes a
+      relationship.</li>
+    </ol>
+    <p>The direction of the arc is significant: it always points
+    toward the object.</p>
+    <p>The <a title="node">nodes</a> of an RDF graph
+    are its subjects and objects.</p>
+    <p>The assertion of an RDF triple says that some relationship,
+    indicated by the predicate, holds between the things denoted by
+    subject and object of the triple. The assertion of an RDF graph
+    amounts to asserting all the triples in it, so the meaning of
+    an RDF graph is the conjunction (logical AND) of the statements
+    corresponding to all the triples it contains. A formal account
+    of the meaning of RDF graphs is given in [[!RDF-MT]].</p>
+</section>
+
+
+<section id="section-IRI-Vocabulary">
+    <h3>IRI-based Vocabulary and Node Identification</h3>
+
+    <p>A <a>node</a> may be an <a>IRI</a>, a <a>literal</a>,
+    or <a title="blank node">blank</a> (having no separate form of identification).
+    Properties are <a title="IRI">IRIs</a>.</p>
+    <p>An <a>IRI</a> or <a>literal</a> used as a node identifies what
+    that node represents. An IRI used as a predicate
+    identifies a relationship between the things represented by the nodes it connects. A
+    predicate IRI may also be a node in the graph.</p>
+    <p>A <a>blank node</a> is a node that is
+    not an IRI or a literal. In the RDF abstract syntax, a
+    blank node is just a unique node that can be used in one or
+    more RDF statements.</p>
+    <p>A convention used by some linear representations of an RDF
+    graph to allow several statements to use the same
+    blank node is to use a <dfn>blank node
+    identifier</dfn>, which is a local identifier that can be
+    distinguished from all IRIs and literals. When graphs are
+    merged, their blank nodes must be kept distinct if meaning is
+    to be preserved; this may call for re-allocation of blank node
+    identifiers. Note that such blank node identifiers are not part
+    of the RDF abstract syntax, and the representation of triples
+    containing blank nodes is entirely dependent on the particular
+    concrete syntax used.</p>
+</section>
+
+
+<section name="section-Datatypes-intro">
+    <h3>Datatypes</h3>
+
+    <p>Datatypes are used by RDF in the representation of values such
+    as integers, floating point numbers and dates.</p>
+
+ <p>
+A datatype consists of a lexical space, a value space and a lexical-to-value 
+mapping, see <a href="#section-Datatypes">section 5</a>.
+</p>
+
+    <p>For example, the lexical-to-value mapping for the XML Schema datatype
+    <var>xsd:boolean</var>, where each member of the value space
+    (represented here as 'T' and 'F') has two lexical representations,
+    is as follows:</p>
+
+    <table border="1" cellpadding="5" summary=
+    "A table detailing the xsd:boolean datatype.">
+      <tr>
+        <th align="left">Value Space</th>
+
+        <td>{T, F}</td>
+      </tr>
+
+      <tr>
+        <th align="left">Lexical Space</th>
+
+        <td>{"0", "1", "true", "false"}</td>
+      </tr>
+
+      <tr>
+        <th align="left">Lexical-to-Value Mapping</th>
+
+        <td>{&lt;"true", T&gt;, &lt;"1", T&gt;, &lt;"0", F&gt;,
+        &lt;"false", F&gt;}</td>
+      </tr>
+    </table>
+
+    <p>RDF predefines just one datatype <code><a>rdf:XMLLiteral</a></code>, used for
+    embedding XML in RDF (see <a href="#section-XMLLiteral">section
+    5.1</a>).</p>
+
+    <p>There is no built-in concept of numbers or dates or other common
+    values. Rather, RDF defers to datatypes that are defined
+    separately, and identified with <a title="IRI">IRIs</a>.
+    The predefined XML Schema
+    datatypes [[!XMLSCHEMA-2]] are expected
+    to be widely used for this purpose.</p>
+
+
+    <p>RDF provides no mechanism for defining new datatypes. XML Schema
+    Datatypes [[!XMLSCHEMA-2]] provides an
+    extensibility framework suitable for defining new datatypes for use
+    in RDF.</p>
+</section>
+
+
+<section name="section-Literals">
+    <h3> Literals</h3>
+
+    <p><a title="literal">Literals</a> are used to identify values such as numbers and dates
+    by means of a lexical representation. Anything represented by a
+    literal could also be represented by an <a>IRI</a>, but it is often more
+    convenient or intuitive to use literals.</p>
+
+    <p>A literal may be the object of an RDF statement, but not the
+    subject or the predicate.</p>
+
+    <p>Literals may be <cite>plain</cite> or <cite>typed</cite> :</p>
+
+    <ul>
+      <li>A <a>plain literal</a> is a string combined
+      with an optional language tag. This may be used for
+      plain text in a natural language. As recommended in the RDF
+      formal semantics [[!RDF-MT]], these plain literals are
+      self-denoting.</li>
+
+
+
+      <li>A <a>typed literal</a> is a string combined with a
+      <a>datatype IRI</a>. It denotes the
+      member of the identified datatype's value space obtained by
+      applying the lexical-to-value mapping to the literal string.</li>
+    </ul>
+
+    <p>Continuing the example from <a href="#section-Datatypes-intro">section
+    3.3</a>, the typed literals that can be defined using the XML
+    Schema datatype <var>xsd:boolean</var> are:</p>
+
+    <table border="1" cellpadding="5" summary=
+    "This table lists the literals of type xsd:boolean.">
+      <tr>
+        <th>Typed Literal</th>
+
+        <th>Lexical-to-Value Mapping</th>
+
+        <th>Value</th>
+      </tr>
+
+      <tr>
+        <td align="center">&lt;xsd:boolean, "true"&gt;</td>
+
+        <td align="center">&lt;"true", T&gt;</td>
+
+        <td align="center">T</td>
+      </tr>
+
+      <tr>
+        <td align="center">&lt;xsd:boolean, "1"&gt;</td>
+
+        <td align="center">&lt;"1", T&gt;</td>
+
+        <td align="center">T</td>
+      </tr>
+
+      <tr>
+        <td align="center">&lt;xsd:boolean, "false"&gt;</td>
+
+        <td align="center">&lt;"false", F&gt;</td>
+
+        <td align="center">F</td>
+      </tr>
+
+      <tr>
+        <td align="center">&lt;xsd:boolean, "0"&gt;</td>
+
+        <td align="center">&lt;"0", F&gt;</td>
+
+        <td align="center">F</td>
+      </tr>
+    </table>
+
+    <p>For text that may contain 
+    markup, use typed literals
+with type <a href="#section-XMLLiteral">rdf:XMLLiteral</a>.
+If language annotation is required, 
+it    must be explicitly included as markup, usually by means of an 
+<code>xml:lang</code> attribute. 
+[[XHTML10]] may be included within RDF
+in this way. Sometimes, in this latter case, 
+ an additional <code>span</code> or <code>div</code> 
+    element is needed to carry an
+<code>xml:lang</code> or <code>lang</code> attribute. 
+    </p>
+
+<p>
+The string in both plain and typed literals is recommended to
+be in Unicode Normal Form C [[!NFC]]. This is motivated
+by [[CHARMOD]] particularly 
+<a href="http://www.w3.org/TR/2003/WD-charmod-20030822/#sec-Normalization">section 4 
+Early Uniform Normalization</a>.
+</p>
+
+</section>
+
+
+<section id="section-SimpleFacts">
+    <h3>RDF Expression of Simple Facts</h3>
+
+    <p>Some simple facts indicate a relationship between
+       two things. 
+Such a fact may be represented as an RDF triple in which the predicate 
+names the relationship, and the subject and object denote the two things.
+
+
+     A familiar representation of such a fact might be
+    as a row in a table in a relational database. The table has
+    two columns, corresponding to the subject and the object of the 
+    RDF triple. 
+    The name of the table corresponds to the predicate
+    of the RDF triple. A further familiar representation may be as a 
+    two place predicate
+    in first order logic.</p>
+    
+    <p>
+Relational databases permit a table to have an arbitrary number of columns, 
+a row of which expresses information corresponding to a predicate in first 
+order logic with an arbitrary number of places.  Such a row, or predicate, 
+has to be decomposed for representation as RDF triples.  A simple form of 
+decomposition introduces a new blank node, corresponding to the row, and a 
+new triple is introduced for each cell in the row.  The subject of each 
+triple is the new blank node, the predicate corresponds to the column name, 
+and object corresponds to the value in the cell.  The new blank node may 
+also have an <code>rdf:type</code> property whose value corresponds 
+to the table name.
+</p>
+    
+   <p>As an example, consider Figure 6 from the [[RDF-PRIMER]]:
+
+</p>
+
+    <div class="figure">
+      <img src="fig6may19" alt="Using a Blank Node" /><br />
+      RDF Primer Figure 6: Using a Blank Node
+    </div>
+
+
+ <p>
+This information might correspond to a row in a table <code>"STAFFADDRESSES"</code>,
+ with a primary key 
+<code>STAFFID</code>,
+ and additional columns 
+<code>STREET</code>,
+<code>STATE</code>,
+<code>CITY</code> and
+<code>POSTALCODE</code>.
+  </p>
+
+    <p>
+Thus, a more complex fact is expressed in RDF using a 
+conjunction (logical-AND) of simple binary relationships.  RDF does not 
+provide means to express negation (NOT) or disjunction (OR).  </p>
+
+    <p>Through its use of extensible IRI-based vocabularies, RDF
+    provides for expression of facts about arbitrary subjects; i.e.
+    assertions of named properties about specific named things. An IRI
+    can be constructed for any thing that can be named, so RDF facts
+    can be about any such things. <!--
+            And, as noted above, RDF also
+            provides for expression of assertions about unnamed things, which
+            may be fully identifiable in terms of such assertions [[TAP-RBD]].
+            -->
+    </p>
+</section>
+
+
+<section id="section-Entailment">
+    <h3>Entailment</h3>
+
+    <p>The ideas on meaning and inference in RDF are underpinned by the
+    formal concept of <a href="http://www.w3.org/TR/2004/REC-rdf-mt-20040210/#entail">
+<cite>entailment</cite></a>, as 
+      discussed in the RDF
+    semantics document [[!RDF-MT]].
+In brief,  an RDF expression A is said to
+<dfn title="entailment">entail</dfn> another RDF&nbsp;expression B
+if every possible
+arrangement of things in the world that makes A true also makes B
+true. On this basis, if the truth of A is presumed or demonstrated
+then the truth of B can be inferred . 
+</p>
+</section>
+
+</section>
+
+
+<section id="section-URIspaces">
+    <h2>RDF Vocabulary IRI and Namespace</h2>
+
+    <p>RDF uses <a title="IRI">IRIs</a> to identify resources
+    and properties. Certain
+    IRIs are given specific meaning by RDF.  Specifically, IRIs
+    with the following leading substring are defined by the RDF
+    specifications:</p>
+
+    <ul>
+      <li><code>http://www.w3.org/1999/02/22-rdf-syntax-ns#</code>
+      (conventionally associated with namespace prefix <code>rdf:</code>)</li>
+<!--
+      <li><code>http://www.w3.org/2000/01/rdf-schema#</code>
+      (conventionally associated with namespace prefix <code>rdfs:</code>)</li>
+-->
+    </ul>
+    <p>Used with the RDF/XML serialization, this IRI prefix
+    string corresponds to XML namespace names [[!XML-NAMES]] associated with the RDF
+    vocabulary terms.</p>
+
+    <p class="note">This namespace name is the same
+      as that used in the earlier RDF recommendation [[RDF-SYNTAX]].</p>
+
+    <p>Vocabulary terms in the <code>rdf:</code>
+    namespace are listed in <a
+    href="http://www.w3.org/TR/2004/REC-rdf-syntax-grammar-20040210/#section-Namespace">
+    section 5.1</a> of the RDF syntax specification [[!RDF-SYNTAX-GRAMMAR]]. Some of these terms are
+    defined by the RDF specifications to denote specific concepts.
+    Others have syntactic purpose (e.g. rdf:ID is part of
+    the RDF/XML syntax).</p>
+<!--
+    <p>Vocabulary terms defined in the <code>rdfs:</code> namespace are defined in the RDF
+    schema vocabulary specification [[RDF-SCHEMA]].</p>
+-->
+</section>
+
+
+<section name="section-Datatypes">
+   <h2>Datatypes</h2>
+
+    <p class="issue">This section perhaps should discuss
+    <a href="http://www.w3.org/TR/rdf-mt/#dtype_interp">the XSD datatype map</a>
+    and <code><a href="http://www.w3.org/TR/rdf-plain-literal/">rdf:PlainLiteral</a></code>.</p>
+
+<p>
+The datatype abstraction used in RDF is compatible with 
+the abstraction used in
+XML Schema Part 2:
+    Datatypes [[!XMLSCHEMA-2]].</p>
+<p>
+A datatype consists of a lexical space, a value space and a lexical-to-value 
+mapping.
+</p>
+<p>The <dfn>lexical space</dfn> of a datatype is a set of Unicode [[!UNICODE]] strings.</p>
+<p>
+The <dfn>lexical-to-value mapping</dfn> of a datatype is a set of pairs whose 
+first element belongs to 
+the <a>lexical space</a> of the datatype, 
+and the second element belongs to the 
+ <dfn>value space</dfn> of the datatype:
+</p>
+<ul>
+<li>
+Each member of the lexical space is paired with (maps to) exactly one member 
+of the value space.
+</li>
+<li>
+Each member of the value space may be paired with any number (including 
+zero) of members of the lexical space (lexical representations for that 
+value).
+</li>
+</ul>
+<p>
+A datatype is identified by one or more IRIs.
+</p>
+<p>
+RDF may be used with any datatype definition that conforms to this
+abstraction, even if not defined in terms of XML Schema.
+</p>
+   <p>Certain XML Schema built-in datatypes are not suitable for use 
+    within RDF. For example, the 
+<a href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#QName">QName</a> 
+datatype  requires a namespace declaration to be in scope during
+    the mapping, and is not recommended for use in RDF.
+    [[!RDF-MT]] contains a 
+<a href="http://www.w3.org/TR/2004/REC-rdf-mt-20040210/#dtype_interp">more detailed discussion</a>
+ of specific XML Schema built-in datatypes. </p>
+
+<div class="note">
+<p>When the datatype is defined using XML Schema:
+</p>
+<ul>
+<li>
+All values correspond to some lexical form, either using
+the lexical-to-value mapping of the datatype or if it is a union
+datatype with a lexical mapping associated with one of the member
+datatypes.
+</li>
+<li>
+XML Schema facets remain part of the datatype and are used by the XML 
+Schema mechanisms that control the lexical space and the value space; 
+however, RDF does not define a standard mechanism to access these facets.</li>
+
+<li>In [[XMLSCHEMA-1]],
+<a href="http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#section-White-Space-Normalization-during-Validation">
+white space normalization</a> occurs
+during 
+<a href="http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#key-vn">validation</a> 
+according to the value of the 
+<a href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#rf-whiteSpace">whiteSpace
+facet</a>. The lexical-to-value mapping used in RDF datatyping
+occurs after this, so that the whiteSpace facet has no
+effect in RDF datatyping.
+</li>
+</ul>
+
+</div>
+
+
+<section id="section-XMLLiteral">
+    <h3>XML Content within an RDF Graph</h3>
+
+    <p class="issue">The canonicalization rules required for XML literals
+    are quite complicated. Increasingly, RDF is produced and consumed in
+    environments where no XML parser and canonicalization engine is
+    available. A possible change to relax the requirements for the
+    lexical space, while retaining the value space, is under discussion.
+    This is <a href="http://www.w3.org/2011/rdf-wg/track/issues/13">ISSUE-13</a>.</p>
+
+    <p>RDF provides for XML content as a possible literal value. This
+    typically originates from the use of
+    <code>rdf:parseType="Literal"</code> in the RDF/XML Syntax [[!RDF-SYNTAX-GRAMMAR]].</p>
+
+    <p>Such content is indicated in an RDF graph using a typed literal
+    whose datatype is a special built-in datatype
+    <dfn>rdf:XMLLiteral</dfn>,
+    defined as follows.</p>
+
+   
+    <dl>
+      <dt><a name="XMLLiteral-uri" id="XMLLiteral-uri">An IRI for
+identifying this datatype</a></dt>
+
+      <dd>is
+      <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>.</dd>
+
+      
+ 
+
+      <dt><a name="XMLLiteral-lexical-space" id="XMLLiteral-lexical-space">The lexical space</a></dt>
+
+<dd>is the set of all
+strings:
+<ul>
+<li>which are well-balanced, self-contained 
+<a href="http://www.w3.org/TR/2000/REC-xml-20001006#NT-content">
+XML content</a> 
+[[!XML10]];
+</li>
+<li>for which encoding as UTF-8 
+[[!RFC2279]] yields 
+<a href="http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718/#def-exclusive-canonical-XML">
+exclusive
+Canonical XML </a> (with comments, with empty  
+<a href="http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718/#def-InclusiveNamespaces-PrefixList">
+InclusiveNamespaces PrefixList
+</a>) [[!XML-EXC-C14N]];
+</li>
+<li>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> [[!XML-NAMES]]</li>
+</ul>
+</dd>
+
+
+   <dt><a name="XMLLiteral-value-space" id="XMLLiteral-value-space">The value space</a></dt>
+
+      <dd>is a set of entities, called XML values, which is:
+<ul>
+<li>disjoint from the lexical space;</li>
+<li>disjoint from the value space of any other datatype that is not explicitly defined as a sub- or supertype of this datatype;</li>
+<li>disjoint from the set of Unicode character strings [[!UNICODE]];</li>
+<li>and in 1:1 correspondence with the lexical space.</li>
+</ul>
+</dd>
+
+      <dt><a name="XMLLiteral-mapping" id="XMLLiteral-mapping">The lexical-to-value mapping</a></dt>
+
+      <dd>
+is a one-one mapping from the lexical space onto the value space,
+    i.e. it is both injective and surjective.
+</dd> 
+
+
+
+    </dl>
+
+
+      <p class="note">Not all values of this datatype are compliant
+      with XML 1.1 [[XML11]]. If compliance
+      with XML 1.1 is desired, then only those values that are
+<a href="http://www.w3.org/TR/2002/CR-xml11-20021015/#sec2.13">fully
+      normalized</a> according to XML 1.1 should be used.</p>
+
+      <p class="note">XML values can be thought of as the 
+[[XML-INFOSET]] or the [[XPATH]]
+nodeset corresponding to the lexical form, with an appropriate equality
+function.</p>
+
+      <p class="note">RDF applications may use additional equivalence relations, such as
+that which relates an 
+<a href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#string"><code>xsd:string</code></a>
+ 
+with an <code>rdf:XMLLiteral</code> corresponding to
+a single text node of the same string.</p>
+
+</section>
+
+</section>
+
+
+<section id="section-Graph-syntax">
+    <h2>Abstract Syntax</h2>
+
+    <p>This section defines the RDF abstract syntax. The RDF abstract
+    syntax is a set of triples, called the RDF graph.</p>
+
+    <p>This section also defines equivalence between RDF graphs. A
+    definition of equivalence is needed to support the RDF Test Cases
+    [[RDF-TESTCASES]] specification.</p>
+
+<p class="note">This <em>abstract</em> syntax is the
+syntax over which the formal semantics are defined.
+Implementations are free to represent RDF graphs in
+any other equivalent form.  As an example:
+in an RDF graph,
+literals with datatype <tt>rdf:XMLLiteral</tt> can be represented
+in a non-canonical
+format, and canonicalization performed during the comparison between two
+such literals. In this example the comparisons may be
+being performed either between syntactic structures or
+between their denotations in the domain of discourse.
+Implementations that do not require any such comparisons can
+hence be optimized.
+</p>
+
+    <p class="issue">The SPARQL WG proposed to add definitions for
+    “RDF Term” and “Simple Literal”.</p>
+
+
+<section id="section-triples">
+    <h3>RDF Triples</h3>
+
+    <p>An <dfn>RDF triple</dfn> contains three components:</p>
+
+    <ul>
+      <li>the <dfn>subject</dfn>, which is an
+      <a>IRI</a> or a <a>blank node</a></li>
+
+      <li>the <dfn>predicate</dfn>, which is an <a>IRI</a></li>
+
+      <li>the <dfn>object</dfn>, which is an <a>IRI</a>,
+      a <a>literal</a> or a <a>blank node</a></li>
+    </ul>
+
+    <p>An RDF triple is conventionally written in the order subject,
+    predicate, object.</p>
+    
+    <p>The predicate is also known as the <dfn>property</dfn> of the triple.</p>
+</section>
+
+
+<section id="section-rdf-graph">
+    <h3>RDF Graph</h3>
+
+    <p>An <dfn>RDF graph</dfn> is a set of RDF triples.</p>
+
+    <p>The set of <dfn title="node">nodes</dfn> of an RDF graph is the set of subjects and objects of
+    triples in the graph.</p>
+</section>
+
+    
+<section id="section-graph-equality">
+    <h3>Graph Equivalence</h3>
+
+    <p>Two <a title="RDF graph">RDF graphs</a> <var>G</var> and <var>G'</var> are equivalent 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">RDF literals</a> <var>lit</var> which
+      are nodes of <var>G</var>.</li>
+
+      <li><var>M(uri)=uri</var> for all <a title="IRI">IRIs</a> <var>uri</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>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>.</p>
+</section>
+    
+
+<section id="section-IRIs">
+    <h3>IRIs</h3>
+
+    <p>An <dfn title="IRI"><acronym title="Internationalized Resource Identifier">IRI</acronym></dfn>
+    (Internationalized Resource Identifier) within an RDF graph
+    is a Unicode string [[!UNICODE]] that conforms to the syntax
+    defined in RFC 3987 [[!IRI]]. IRIs are a generalization of
+    <dfn title="URI"><acronym title="Uniform Resource Identifier">URI</acronym>s</dfn>
+    [[URI]]. Every absolute URI and URL is an IRI.</p>
+
+    <p>IRIs in the RDF abstract syntax MUST be absolute, and MAY
+    contain a fragment identifier.</p>
+
+    <p>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 [[!IRI]]. Further normalization MUST NOT be performed when
+    comparing IRIs for equality.</p>
+
+    <p class="note">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 [[!IRI]]. 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 class="note">Some concrete syntaxes permit relative IRIs
+    as a shorthand for absolute IRIs, and define how to resolve
+    the relative IRIs against a base IRI.</p>
+
+    <p class="note">Previous versions of RDF used the term
+    “<dfn>RDF URI Reference</dfn>” instead of “IRI” and allowed
+    additional characters:
+    “<code>&lt;</code>”, “<code>&gt;</code>”,
+    “<code>{</code>”, “<code>}</code>”,
+    “<code>|</code>”, “<code>\</code>”,
+    “<code>^</code>”, “<code>`</code>”,
+    ‘<code>“</code>’ (double quote), and “<code> </code>” (space).
+    In IRIs, these characters must be percent-encoded as
+    described in <a href="http://tools.ietf.org/html/rfc3986#section-2.1">section 2.1</a>
+    of [[URI]].</p>
+
+    <div class="note">
+      <p>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 [[!IRI]]. Non-normalized forms that should be 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 IRI syntax</li>
+        <li>Explicitly stated HTTP default port
+          (<code>http://example.com:80/</code>);
+          <code>http://example.com/</code> is preferrable</li>
+        <li>Completely empty path in HTTP IRIs
+          (<code>http://example.com</code>);
+          <code>http://example.com/</code> is preferrable</li>
+        <li>“<code>/./</code>” or “<code>/../</code>” in the path
+          component of an IRI</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 [[!NFC]]</li>
+      </ul>
+    </div>
+</section>
+
+
+<section id="section-Graph-Literal">
+    <h3>RDF Literals</h3>
+
+    <p class="issue">Currently, there are three different
+    kinds of literals for expressing strings: plain literals,
+    <a href=""><code>rdf:PlainLiteral</code></a> [[RDF-PLAINLITERAL]],
+    and <code>xsd:string</code>. Some consolidation of these
+    forms is under consideration. This is
+    <a href="http://www.w3.org/2011/rdf-wg/track/issues/12">ISSUE-12</a>.</p>
+
+<p>A <dfn>literal</dfn> in an <a>RDF graph</a>
+contains one or two named components.</p>
+<p>All literals have a <dfn>lexical form</dfn> being a Unicode
+[[!UNICODE]] string, which SHOULD be in Normal Form C [[!NFC]].</p>
+
+
+    <p><dfn title="plain literal">Plain literals</dfn> have 
+    a <a>lexical form</a> and optionally a <dfn>language tag</dfn> as
+    defined by [[!BCP47]]. The language tag, if present, MUST be
+    well-formed according to
+    <a href="http://tools.ietf.org/html/rfc5646#section-2.2.9">section 2.2.9</a>
+    of [[!BCP47]], and MUST be normalized to lowercase.</p>
+
+    <p><dfn title="typed literal">Typed literals</dfn> have a <a>lexical form</a>
+    and a <dfn>datatype IRI</dfn> being an <a>IRI</a>.</p>
+ 
+
+      <p class="note">Literals in which the lexical form begins with a
+      composing character (as defined by [[CHARMOD]]) are allowed however they may cause
+      interoperability problems, particularly with XML version 1.1 [[XML11]].</p>
+
+    <p class="note">Earlier versions of RDF permitted tags that
+    adhered to the generic tag/subtag syntax of language tags,
+    but were not well-formed according to [[!BCP47]]. Such
+    language tags do not conform to RDF 1.1.</p>
+
+      <p class="note">When using the language tag, care must be
+      taken not to confuse language with locale. The language
+      tag relates only to human language text. Presentational
+      issues should
+      be addressed in end-user applications.</p>
+
+      <p class="note">The case normalization of 
+language tags is part of
+ the description of the abstract syntax, and consequently the abstract
+ behaviour of RDF applications. It does not constrain an
+ RDF implementation to actually normalize the case. Crucially, the result
+ of comparing two language tags should not be sensitive to the case of
+ the original input.</p>
+
+
+<section id="section-Literal-Equality">
+    <h4>Literal Equality</h4>
+
+    <p>Two literals are equal if and only if all of the following
+    hold:</p>
+
+    <ul>
+      <li>The strings of the two lexical forms compare equal, character
+      by character.</li>
+
+      <li>Either both or neither have language tags.</li>
+
+      <li>The language tags, if any, compare
+      equal.</li>
+
+      <li>Either both or neither have datatype IRIs.</li>
+
+      <li>The two datatype IRIs, if any, compare equal, character by
+      character.</li>
+    </ul>
+
+      <p class="note">RDF Literals are distinct and distinguishable
+      from <a title="IRI">IRIs</a>; e.g. <code>http://example.org/</code> as an RDF
+      Literal (untyped, without a language tag) is not equal to
+      <code>http://example.org/</code> as an IRI.</p>
+</section>
+
+
+<section id="section-Literal-Value">
+    <h4>The Value Corresponding to a Typed Literal</h4>
+
+    <p>The datatype IRI refers to a <a href=
+    "#section-Datatypes">datatype</a>. For XML Schema <a href=
+    "http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#built-in-datatypes">
+    built-in</a> datatypes, IRIs such as
+    <code>http://www.w3.org/2001/XMLSchema#int</code> are used. The IRI
+    of the datatype <a href="#section-XMLLiteral"><tt>rdf:XMLLiteral</tt></a> may be used.
+    There may be other, implementation dependent, mechanisms by which
+    IRIs refer to datatypes.</p>
+
+    <p>The <em>value</em> associated with a typed literal is found by
+    applying the lexical-to-value mapping associated with the datatype IRI to
+    the lexical form.
+    </p>
+
+    <p>
+ If the lexical form is not in
+    the lexical space of the datatype associated with the datatype IRI,
+then no literal value can be associated with the typed literal.
+Such a case, while in error, is not  <em>syntactically</em> ill-formed.</p>
+<!--
+    <p>A typed literal for which the datatype does not map the lexical
+    form to a value is not syntactically ill-formed.</p>
+-->
+    
+
+      <p class="note">
+In application contexts, comparing the values of typed literals (see 
+<a href="#section-Literal-Value">
+section
+6.5.2</a>)
+is usually more helpful than comparing their syntactic forms (see 
+<a href="#section-Literal-Equality">
+section
+6.5.1</a>).
+Similarly, for comparing RDF Graphs,
+semantic notions of entailment (see 
+[[!RDF-MT]]) are usually
+more helpful than syntactic equality (see 
+<a href="#section-graph-equality">
+section
+6.3</a>).</p>
+
+</section>
+
+</section>
+
+
+<section id="section-blank-nodes">
+   <h3>Blank Nodes</h3>
+
+<p>
+The <dfn title="blank node">blank nodes</dfn> in an RDF graph 
+are drawn from an infinite set.
+This set of blank nodes, the set of all <a title="IRI">IRIs</a>
+and the set of all <a title="literal">literals</a> are pairwise disjoint.
+</p>
+<p>
+Otherwise, this set of blank nodes is arbitrary.
+</p>
+<p>RDF makes no reference to any internal structure of blank nodes.
+Given two blank nodes, it is 
+possible to determine whether or not they are the same.</p>
+
+
+<section id="section-skolemization">
+    <h4>Replacing Blank Nodes with IRIs</h4>
+
+    <p>Blank nodes do not have identifiers in the RDF abstract syntax. The
+    <a title="blank node identifier">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 MAY
+    systematically transform some or all of the blank nodes in an RDF graph
+    into IRIs [[!IRI]].  Systems wishing to do this SHOULD mint a new, globally
+    unique IRI (a <dfn>Skolem IRI</dfn>) for each blank node so transformed.</p>
+
+    <p>This transformation does not change the meaning of an RDF graph,
+    provided that the Skolem IRIs do not occur anywhere else.</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 a blank
+    node, and map back to the source blank node where possible.</p>
+
+    <p>Systems that want Skolem IRIs to be recognizable outside of the system
+    boundaries SHOULD use a well-known IRI [[WELL-KNOWN]] with the registered
+    name <code>genid</code>. This is an IRI 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>For example, the authority responsible for the domain
+    <code>example.com</code> could mint the following recognizable Skolem IRI:</p>
+
+    <pre>http://example.com/.well-known/genid/d26a2d0e98334696f4ad70a677abc1f6</pre>
+
+    <p class="issue">IETF registration of the <code>genid</code> name is
+    currently in progress.</p>
+
+    <p class="note">RFC 5785 [[WELL-KNOWN]] only specifies well-known URIs,
+    not IRIs. For the purpose of this document, a well-known IRI is any
+    IRI that results in a well-known URI after IRI-to-URI mapping [[!IRI]].</p>
+</section>
+
+</section>
+
+
+<section id="section-multigraph">
+    <h2>Abstract Syntax for Working with Multiple Graphs</h2>
+
+    <div class="issue">
+        <p>The Working Group will standardize a model and semantics for
+        multiple graphs and graphs stores. The
+        <a href="http://www.w3.org/2011/01/rdf-wg-charter">charter</a> notes:</p>
+
+        <blockquote>The RDF Community has used the
+        term “named graphs” for a number of years in various settings,
+        but this term is ambiguous, and often refers to what could rather
+        be referred as quoted graphs, graph literals, IRIs for graphs,
+        knowledge bases, graph stores, etc. The term “Support for Multiple
+        Graphs and Graph Stores” is used as a neutral term in this charter;
+        this term is not and should not be considered as definitive.
+        The Working Group will have to define the right term(s).</blockquote>
+
+        <p>Progress on the design for this feature is tracked under multiple
+        issues:</p>
+
+        <ul>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/5">ISSUE-5: Should we define Graph Literal datatypes?</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/14">ISSUE-14: What is a named graph and what should we call it?</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/15">ISSUE-15: What is the relationship between the IRI and the triples in a dataset/quad-syntax/etc</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/17">ISSUE-17: How are RDF datasets to be merged?</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/22">ISSUE-22: Does multigraph syntax need to support empty graphs?</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/28">ISSUE-28: Do we need syntactic nesting of graphs (g-texts) as in N3?</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/29">ISSUE-29: Do we support SPARQL's notion of "default graph"?</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/30">ISSUE-30: How does SPARQL's notion of RDF dataset relate our notion of multiple graphs?</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/32">ISSUE-32: Can we identify both g-boxes and g-snaps?</a></li>
+            <li><a href="http://www.w3.org/2011/rdf-wg/track/issues/33">ISSUE-33: Do we provide a way to refer to sub-graphs and/or individual triples?</a></li>
+        </ul>
+    </div>
+</section>
+
+</section>
+
+
+<section id="section-fragID" class="informative">
+    <h2>Fragment Identifiers</h2>
+
+    <p class="issue">This section does not address the case where RDF is
+    embedded in other document formats, such as in RDFa or when an RDF/XML
+    fragment is embedded in SVG. It has been suggested that this may be
+    a general issue for the TAG about the treatment of
+    fragment identifiers when one language is embedded in another. This is
+    <a href="http://www.w3.org/2011/rdf-wg/track/issues/37">ISSUE-37</a>.</p>
+
+    <p class="issue">This section requires updates to address the
+    change from <a title="RDF URI Reference">URI References</a> to <a title="IRI">IRIs</a>.</p>
+
+    <p>RDF uses an <a title="RDF URI Reference">RDF URI
+    Reference</a>, which may include a fragment identifier, as a
+    context free identifier for a resource. RFC 2396 states that the meaning of a fragment
+    identifier depends on the MIME content-type of a document, i.e.
+    is context dependent.</p>
+    <p>These apparently conflicting views are reconciled by
+    considering that a URI reference in an RDF graph is treated
+    with respect to the MIME type <code>application/rdf+xml</code>
+    [[!RDF-MIME-TYPE]]. Given an RDF URI
+    reference consisting of an absolute URI and a fragment
+    identifier, the fragment identifer identifies the same thing
+    that it does in an <code>application/rdf+xml</code> representation of the
+    resource identified by the absolute URI component. Thus:</p>
+    <ul>
+      <li>we assume that the URI part (i.e. excluding fragment
+      identifier) identifies a resource, which is presumed to have
+      an RDF representation. So when <code>eg:someurl#frag</code> is used in an RDF
+      document, <code>eg:someurl</code> is taken to
+      designate some RDF document (even when no such document can
+      be retrieved).</li>
+      <li><code>eg:someurl#frag</code> means the thing
+      that is indicated, according to the rules of the
+      <code>application/rdf+xml</code> MIME content-type as
+      a “fragment” or “view” of the RDF document at
+      <code>eg:someurl</code>. If the document does not
+      exist, or cannot be retrieved, or is available only in
+      formats other than <code>application/rdf+xml</code>, then exactly what
+      that view may be is somewhat undetermined, but that does not
+      prevent use of RDF to say things about it.</li>
+      <li>the RDF treatment of a fragment identifier allows it to
+      indicate a thing that is entirely external to the document,
+      or even to the “shared information space” known as the Web.
+      That is, it can be a more general idea, like some particular
+      car or a mythical Unicorn.</li>
+      <li>in this way, an <code>application/rdf+xml</code> document acts as an
+      intermediary between some Web retrievable documents (itself,
+      at least, also any other Web retrievable URIs that it may
+      use, possibly including schema URIs and references to other
+      RDF documents), and some set of possibly abstract or non-Web
+      entities that the RDF may describe.</li>
+    </ul>
+    <p>This provides a handling of URI references and their
+    denotation that is consistent with the RDF model theory and
+    usage, and also with conventional Web behavior. Note that
+    nothing here requires that an RDF application be able to
+    retrieve any representation of resources identified by the URIs
+    in an RDF graph.</p>
+</section>
+
+
+<section id="section-Acknowledgments" class="informative">
+    <h2>Acknowledgments</h2>
+
+    <p class="issue">This section does not yet list those who made
+    contributions to the RDF 1.1 version, nor does it list the
+    current RDF WG members.</p>
+
+    <p>This document contains a significant contribution from Pat
+    Hayes, Sergey Melnik and Patrick Stickler, under whose leadership
+    was developed the framework described in the RDF family of
+    specifications for representing datatyped values, such as integers
+    and dates.</p>
+
+    <p>The editors acknowledge valuable contributions from the
+    following: <!--</p>
+
+    <ul>-->
+      <!--<li>-->Frank Manola, <!--</li>-->
+
+      <!--<li>-->Pat Hayes, <!--</li>-->
+
+      <!--<li>-->Dan Brickley, <!--</li>-->
+
+      <!--<li>-->Jos de Roo, <!--</li>-->
+
+      <!--<li>-->Dave Beckett, <!--</li>-->
+
+      <!--<li>-->Patrick Stickler, <!--</li>-->
+
+      <!--<li>-->Peter F. Patel-Schneider, <!--</li>-->
+
+      <!--<li>-->Jerome Euzenat, <!--</li>-->
+
+      <!--<li>-->Massimo Marchiori, <!--</li>-->
+
+      <!--<li>-->Tim Berners-Lee, <!--</li>-->
+
+      <!--<li>-->Dave Reynolds <!--</li>-->
+
+      <!--<li>-->and Dan Connolly. <!--</li>-->
+<!--
+      <li class="todo">[[[Other contributors]]]</li>
+    </ul>
+-->
+</p>
+    <p>Jeremy Carroll thanks <a href="mailto:[email protected]">Oreste
+    Signore</a>, his host at the <a href="http://www.w3c.it/">W3C
+    Office in Italy</a> and <a href="http://www.isti.cnr.it" lang="it"
+    xml:lang="it">Istituto di Scienza e Tecnologie dell'Informazione
+    “Alessandro Faedo”</a>, part of the <a href="http://www.cnr.it"
+    lang="it" xml:lang="it">Consiglio Nazionale delle Ricerche</a>,
+    where Jeremy is a visiting researcher.</p>
+
+    <p>This document is a product of extended deliberations by the
+    RDFcore Working Group, whose members have included:
+
+<!--</p><ul>-->
+      <!--<li>-->Art Barstow (W3C), <!--</li>-->
+
+      <!--<li>-->Dave Beckett (ILRT), <!--</li>-->
+
+      <!--<li>-->Dan Brickley (ILRT), <!--</li>-->
+
+      <!--<li>-->Dan Connolly (W3C), <!--</li>-->
+
+      <!--<li>-->Jeremy Carroll (Hewlett Packard), <!--</li>-->
+
+      <!--<li>-->Ron Daniel (Interwoven Inc), <!--</li>-->
+
+      <!--<li>-->Bill dehOra (InterX), <!--</li>-->
+
+      <!--<li>-->Jos De Roo (AGFA), <!--</li>-->
+
+      <!--<li>-->Jan Grant (ILRT), <!--</li>-->
+
+      <!--<li>-->Graham Klyne (Nine by Nine), <!--</li>-->
+
+      <!--<li>-->Frank Manola (MITRE Corporation), <!--</li>-->
+
+      <!--<li>-->Brian McBride (Hewlett Packard), <!--</li>-->
+
+      <!--<li>-->Eric Miller (W3C), <!--</li>-->
+
+      <!--<li>-->Stephen Petschulat (IBM), <!--</li>-->
+
+      <!--<li>-->Patrick Stickler (Nokia), <!--</li>-->
+
+      <!--<li>-->Aaron Swartz (HWG), <!--</li>-->
+
+      <!--<li>-->Mike Dean (BBN Technologies / Verizon), <!--</li>-->
+
+      <!--<li>-->R. V. Guha (Alpiri Inc), <!--</li>-->
+
+      <!--<li>-->Pat Hayes (IHMC), <!--</li>-->
+
+      <!--<li>-->Sergey Melnik (Stanford University) and <!--</li>-->
+
+      <!--<li>-->Martyn Horner (Profium Ltd). <!--</li>-->
+    </p> <!--</ul>-->
+    <p>This specification also draws upon an earlier RDF Model and
+    Syntax document edited by Ora Lassilla and Ralph Swick, and RDF
+    Schema edited by Dan Brickley and R. V. Guha. RDF and RDF Schema
+    Working Group members who contributed to this earlier work are:
+
+     <!--</p><ul>-->
+      <!--<li>-->Nick Arnett (Verity), <!--</li>-->
+
+      <!--<li>-->Tim Berners-Lee (W3C), <!--</li>-->
+
+      <!--<li>-->Tim Bray (Textuality), <!--</li>-->
+
+      <!--<li>-->Dan Brickley (ILRT / University of Bristol), <!--</li>-->
+
+      <!--<li>-->Walter Chang (Adobe), <!--</li>-->
+
+      <!--<li>-->Sailesh Chutani (Oracle), <!--</li>-->
+
+      <!--<li>-->Dan Connolly (W3C), <!--</li>-->
+
+      <!--<li>-->Ron Daniel (DATAFUSION), <!--</li>-->
+
+      <!--<li>-->Charles Frankston (Microsoft), <!--</li>-->
+
+      <!--<li>-->Patrick Gannon (CommerceNet), <!--</li>-->
+
+      <!--<li>-->R. V. Guha (Epinions, previously of Netscape
+      Communications), <!--</li>-->
+
+      <!--<li>-->Tom Hill (Apple Computer), <!--</li>-->
+
+      <!--<li>-->Arthur van Hoff (Marimba), <!--</li>-->
+
+      <!--<li>-->Renato Iannella (DSTC), <!--</li>-->
+
+      <!--<li>-->Sandeep Jain (Oracle), <!--</li>-->
+
+      <!--<li>-->Kevin Jones, (InterMind), <!--</li>-->
+
+      <!--<li>-->Emiko Kezuka (Digital Vision Laboratories), <!--</li>-->
+
+      <!--<li>-->Joe Lapp (webMethods Inc.), <!--</li>-->
+
+      <!--<li>-->Ora Lassila (Nokia Research Center), <!--</li>-->
+
+      <!--<li>-->Andrew Layman (Microsoft), <!--</li>-->
+
+      <!--<li>-->Ralph LeVan (OCLC), <!--</li>-->
+
+      <!--<li>-->John McCarthy (Lawrence Berkeley National Laboratory), <!--</li>-->
+
+      <!--<li>-->Chris McConnell (Microsoft), <!--</li>-->
+
+      <!--<li>-->Murray Maloney (Grif), <!--</li>-->
+
+      <!--<li>-->Michael Mealling (Network Solutions), <!--</li>-->
+
+      <!--<li>-->Norbert Mikula (DataChannel), <!--</li>-->
+
+      <!--<li>-->Eric Miller (OCLC), <!--</li>-->
+
+      <!--<li>-->Jim Miller (W3C, emeritus), <!--</li>-->
+
+      <!--<li>-->Frank Olken (Lawrence Berkeley National Laboratory), <!--</li>-->
+
+      <!--<li>-->Jean Paoli (Microsoft), <!--</li>-->
+
+      <!--<li>-->Sri Raghavan (Digital/Compaq), <!--</li>-->
+
+      <!--<li>-->Lisa Rein (webMethods Inc.), <!--</li>-->
+
+      <!--<li>-->Paul Resnick (University of Michigan), <!--</li>-->
+
+      <!--<li>-->Bill Roberts (KnowledgeCite), <!--</li>-->
+
+      <!--<li>-->Tsuyoshi Sakata (Digital Vision Laboratories), <!--</li>-->
+
+      <!--<li>-->Bob Schloss (IBM), <!--</li>-->
+
+      <!--<li>-->Leon Shklar (Pencom Web Works), <!--</li>-->
+
+      <!--<li>-->David Singer (IBM), <!--</li>-->
+
+      <!--<li>-->Wei (William) Song (SISU), <!--</li>-->
+
+      <!--<li>-->Neel Sundaresan (IBM), <!--</li>-->
+
+      <!--<li>-->Ralph Swick (W3C), <!--</li>-->
+
+      <!--<li>-->Naohiko Uramoto (IBM), <!--</li>-->
+
+      <!--<li>-->Charles Wicksteed (Reuters Ltd.), <!--</li>-->
+
+      <!--<li>-->Misha Wolf (Reuters Ltd.) and <!--</li>-->
+
+      <!--<li>-->Lauren Wood (SoftQuad). <!--</li>-->
+    <!--</ul>--></p>
+</section>
+
+
+<section class="appendix informative" id="changes">
+  <h2>Changes from RDF 2004</h2>
+
+  <ul>
+    <li>2011-06-01: Replaced the URI References section with <a href="#section-IRIs">new section on IRIs</a>, and changed “RDF URI Reference” to “IRI” throughout the document, except in <a href="#section-fragID">section 8</a>.</li>
+    <li>2011-06-01: Changed language tag definition to require well-formedness according to BCP47; added a note that this invalidates some RDF</li>
+    <li>2011-05-25: Added boxes for known WG issues throught the document</li>
+    <li>2011-05-25: Deleted “Structure of this Document” section, it added no value beyond the TOC</li>
+    <li>2011-05-25: Implemented resolution of <a href="http://www.w3.org/2011/rdf-wg/track/issues/40">ISSUE-40: Skolemization advice in the RDF dcocument</a> by adding a section on <a href="#section-skolemization">Replacing Blank Nodes with IRIs</a></li>
+    <li>2011-05-25: rdf:XMLLiteral is disjoint from any datatype not explicitly related to it, per erratum <a href="http://www.w3.org/2001/sw/RDFCore/errata#concept-xmlliteral">[concept-xmlliteral]</a></li>
+    <li>2011-05-25: Added Conformance section with RFC2119 reference</li>
+    <li>2011-05-25: Updated all W3C references to latest editions, and Unicode from v3 to v4</li>
+    <li>2011-05-24: Converted to ReSpec, changed metadata to reflect RDF 1.1</li>
+  </ul>
+</section>
+
+
+<section id="references">
+    <div class="issue">
+      <ul>
+        <li>RFC 2279 is obsoleted by RFC 3629</li>
+        <li>Change OWL reference to OWL2?</li>
+        <li>Change XHTML10 reference to XHTML5?</li>
+      </ul>
+    </div>
+</section>
+
+  </body>
+</html>
+