--- a/rdf-concepts/index.html Thu Jul 21 11:42:51 2011 +0100
+++ b/rdf-concepts/index.html Thu Jul 21 13:25:51 2011 +0100
@@ -335,21 +335,18 @@
<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>
+ <p>Literals may be <cite>typed</cite> or <cite>language-tagged</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>
+
+ <li>A <a>language-tagged literal</a> is a string combined
+ with a language tag. This may be used for
+ plain text in a natural language. Language-tagged literals
+ are self-denoting.</li>
</ul>
<p>Continuing the example from <a href="#section-Datatypes-intro">section
@@ -819,29 +816,44 @@
<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
+ <p class="issue">This section is a major departure from RDF 2004
+ as <a title="simple literal">simple literals</a> are now treated
+ as syntactic sugar for <code>xsd:string</code>
+ <a title="typed literal">typed literals</a>. Further changes
+ to RDF's literal design are under consideration.
+ <a title="language-tagged literal">Language-tagged literals</a>
+ may receive a datatype, and
+ <a href="http://www.w3.org/TR/rdf-plain-literal/"><code>rdf:PlainLiteral</code>s</a> [[RDF-PLAINLITERAL]]
+ may be folded into the design somehow. 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>A <dfn>literal</dfn> in an <a>RDF graph</a> is either a
+ <a>typed literal</a> or a <a>language-tagged literal</a>.</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
+ <p><dfn title="language-tagged literal">Language-tagged literals</dfn> have
+ a <a>lexical form</a> and a non-empty <dfn>language tag</dfn> as
+ defined by [[!BCP47]]. The language tag MUST be well-formed according to
<a href="http://tools.ietf.org/html/bcp47#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>Concrete syntaxes MAY support <dfn title="simple literal">simple
+ literals</dfn>, consisting of only a <a>lexical form</a>
+ without any language tag or datatype IRI. Simple literals only
+ exist in concrete syntaxes, and are treated as
+ syntactic sugar for abstract syntax
+ <a title="plain literal">typed literals</a> with the datatype IRI
+ <code>http://www.w3.org/2001/XMLSchema#string</code>.
+ Simple literals and <a>language-tagged literals</a> are
+ collectively known as <dfn title="plain literal">plain literals</dfn>.</p>
+
+ <p class="note">Earlier versions of RDF allowed
+ <a title="simple literal">simple literals</a> in the abstract syntax.</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
@@ -1317,6 +1329,7 @@
<h2>Changes from RDF 2004</h2>
<ul>
+ <li>2011-07-21: Updated the two sections on literals to reflect the <a href="">ISSUE-12 resolution</a> that simple literals are no longer part of the abstract syntax. Formally introduced the terms “language-tagged literal”, “simple literal”.</li>
<li>2011-07-21: Updated the introduction, and removed many mentions of RDF/XML. Changed the normative reference for the terms in the RDF namespace from the RDF/XML spec to the RDF Schema spec. Removed any mention of the 1999 version of RDF.</li>
<li>2011-07-21: Replaced RFC 2279 reference (UTF-8) with RFC 3629</li>
<li>2011-07-20: Removed informative sections “Motivations and Goals” (see <a href="http://www.w3.org/TR/rdf-concepts/#section-Overview">RDF 2004 version</a>) and “RDF Expression of Simple Facts” (see <a href="http://www.w3.org/TR/rdf-concepts/#section-SimpleFacts">RDF 2004 version</a>)</li>