authorSandro Hawke <>
Thu, 10 May 2012 20:02:16 -0400
changeset 355 65b58c9eed81
parent 354 61e8e4c2401e (current diff)
parent 353 41059e4c777d (diff)
child 356 c66759ebc6ad
--- a/rdf-concepts/index.html	Thu May 10 20:01:51 2012 -0400
+++ b/rdf-concepts/index.html	Thu May 10 20:02:16 2012 -0400
@@ -5,7 +5,7 @@
     <title>RDF 1.1 Concepts and Abstract Syntax</title>
     <style type="text/css">
 .figure { font-weight: bold; text-align: center; }
-table.xsd-types td, table.xsd-types th { border: 1px solid #ddd; padding: 0.1em 0.5em; }
+table td, table th { border: 1px solid #ddd; padding: 0.2em 0.5em; }
     <script src='../ReSpec.js/js/respec.js' class='remove'></script>
     <script class='remove'>
@@ -246,12 +246,18 @@
     <li>A good way of communicating the intended referent to the world
-    is to set up the IRI so that it resolves to such a document.</li>
+    is to set up the IRI so that it
+    <a href="">dereferences</a>
+    [[WEBARCH]] to such a document.</li>
     <li>Such a document can, in fact, be an <a>RDF document</a>
     that describes the denoted resource by means of
     <a title="RDF statement">RDF statements</a>.</li>
+<section id="vocabularies">
+    <h3>RDF Vocabularies and Namespace IRIs</h3>
     <p>An <dfn>RDF vocabulary</dfn> is a collection of <a title="IRI">IRIs</a>
     with clearly established <a title="referent">referents</a>
@@ -261,9 +267,32 @@
     RDF vocabularies. Some such vocabularies are mentioned in the
     Primer [[RDF-PRIMER]].</p>
-    <p class="issue">It has been suggested that this specification should
-    also define terms such as “<dfn>namespace</dfn>”, “<dfn>namespace IRI</dfn>”,
-    and “<dfn>namespace prefix</dfn>”.</p>
+    <p>The <a title="IRI">IRIs</a> in an <a>RDF vocabulary</a> often share
+    a common substring known as a <dfn>namespace IRI</dfn>.
+    Some namespace IRIs are associated by convention with a short name
+    known as a <dfn>namespace prefix</dfn>. Some examples:
+    <table rules="all" summary="Some example namespace prefixes and IRIs">
+      <tr><th>Namespace prefix</th><th>Namespace IRI</th><th>RDF vocabulary</th></tr>
+      <tr><td>rdf</td><td><a href=""><code></code></a></td><td>The RDF built-in vocabulary [[RDF-SCHEMA]]</td></tr>
+      <tr><td>rdfs</td><td><a href=""><code></code></a></td><td>The RDF Schema vocabulary [[RDF-SCHEMA]]</td></tr>
+      <tr><td>xsd</td><td><a href=""><code></code></a></td><td>The <a>RDF-compatible XSD types</a></td></tr>
+    </table>
+    <p>In some contexts it is common to abbreviate <a title="IRI">IRIs</a>
+    that start with <a title="namespace IRI">namespace IRIs</a> by using the
+    associated <a>namespace prefix</a>. For example, the IRI
+    <code></code>
+    would be abbreviated as <code>rdf:XMLLiteral</code>.
+    Note however that these abbreviations are <em>not</em> valid IRIs,
+    and MUST NOT be used in contexts where IRIs are expected.
+    Namespace IRIs and namespace prefixes are <em>not</em> a formal part of the
+    RDF data model. They are merely a syntactic convenience for
+    abbreviating IRIs.</p>
+    <p>The term “<dfn>namespace</dfn>” on its own does not have a
+    well-defined meaning in the context of RDF, but is sometimes incorrectly
+    used to mean “<a>namespace IRI</a>” or “<a>RDF vocabulary</a>”.</p>
@@ -300,12 +329,23 @@
 <section id="conformance">
-    <p>Implementations are free to represent <a title="RDF graph">RDF graphs</a> in
-    any other equivalent form.</p>
+    <p>This specification, <em>RDF 1.1 Concepts and Abstract Syntax</em>,
+    defines a data model and related terminology for use in
+    other specifications, such as
+    <a title="concrete RDF syntax">concrete RDF syntaxes</a>,
+    API specifications, and query languages.
+    Implementations cannot directly conform to
+    <em>RDF 1.1 Concepts and Abstract Syntax</em>,
+    but can conform to such other specifications that are based on the
+    RDF data model.</p>
-    <p class="issue">This section needs to explain what kind of artefact
-    can conform to this specification, and what is required in order to
-    conform.</p>
+    <p>Another specification conforms to
+    <em>RDF 1.1 Concepts and Abstract Syntax</em> if it defines operations
+    in terms of <a title="RDF graph">RDF graphs</a>
+    or <a title="RDF dataset">RDF datasets</a>, and if any use of
+    terminology defined in normative sections of
+    <em>RDF 1.1 Concepts and Abstract Syntax</em>
+    is consistent with its definitions and conformance requirements.</p>
@@ -695,8 +735,7 @@
     <p>The <a title="literal">literals</a> that can be defined using this
     datatype are:</p>
-    <table border="1" cellpadding="5" summary=
-    "This table lists the literals of type xsd:boolean.">
+    <table rules="all" summary="This table lists the literals of type xsd:boolean.">
@@ -732,7 +771,7 @@
     listed in the following table are the
     <dfn>RDF-compatible XSD types</dfn>. Their use is RECOMMENDED.</p>
-    <table class="xsd-types" rules="all">
+    <table rules="all" summary="A list of the RDF-compatible XSD types, with short descriptions">
     <tr><th></th><th>Datatype</th><th>Value space (informative)</th></tr>
     <tr><th rowspan="4">Core types</th><td><a href=""><code>xsd:string</code></a></td><td>Character strings</td></tr>
@@ -830,9 +869,7 @@
     <p>RDF provides for XML content as a possible <a>literal value</a>.
     Such content is indicated in an <a>RDF graph</a> using a <a>literal</a>
     whose <a>datatype</a> is a special built-in datatype
-    <code>rdf:XMLLiteral</code>.</p>
-    <p><code><dfn>rdf:XMLLiteral</dfn></code> is defined as follows.</p>
+    <code><dfn>rdf:XMLLiteral</dfn></code>, which is defined as follows:</p>
       <dt><a name="XMLLiteral-uri" id="XMLLiteral-uri">An IRI denoting
@@ -863,22 +900,11 @@
       <dt><a name="XMLLiteral-mapping" id="XMLLiteral-mapping">The lexical-to-value mapping</a></dt>
-      <dd>is defined as follows:
-      <ul>
-      <li>Let <code>xmldoc</code> be the literal's lexical form,
-      wrapped between an arbitrary XML start-tag and matching end-tag</li>
-      <li>Let <code>domdoc</code> be a DOM
-      <a href=""><code>Document</code></a>
-      object [[!DOM-LEVEL-3-CORE]] corresponding to <code>xmldoc</code></li>
+      <dd><ul>
       <li>Let <code>domfrag</code> be a DOM
       <a href=""><code>DocumentFragment</code></a>
-      whose
-      <a href=""><code>childNodes</code></a>
-      attribute is equal to the
-      <a href=""><code>childNodes</code></a>
-      attribute of <code>domdoc</code>'s
-      <a href=""><code>documentElement</code></a>
-      attribute</li>
+      node [[!DOM-LEVEL-3-CORE]] corresponding to the literal's
+      <a>lexical form</a></li>
       <li>Return <code>domfrag.<a href="">normalize</a>()</code></li>
@@ -1107,6 +1133,9 @@
   <h2>Changes from RDF 2004</h2>
+    <li>2012-05-10: New <a href="#conformance">Conformance section</a> to explain that this specification is not implemented directly, but through other specifications that use our definitions</li>
+    <li>2012-05-10: Simplified <code><a>rdf:XMLLiteral</a></code>'s new value space slightly after feedback from Ivan Herman and Arnaud Le Hors.</li>
+    <li>2012-05-10: Added an informative subsection on <a href="#vocabularies">RDF vocabularies and namespace IRIs</a>.</li>
     <li>2012-05-09: Removed an example from the conformance section that didn't make sense any more with the modified <code>rdf:XMLLiteral</code>. Added some new issue boxes.</li>
     <li>2012-05-09: <code><a>rdf:XMLLiteral</a></code> no longer requires lexical forms to be canonicalized, and the value space is now defined in terms of [[DOM-LEVEL-3-CORE]] (<a href="">ISSUE-13</a>)</li>
     <li>2012-05-09: Removed Section 3 <em>RDF Vocabulary IRI and Namespace</em>; its contents will be folded into the RDF Schema document</li>