add syntax definition

Author: fantasai

css3-namespace/Overview.html

@@ -412,6 +412,23 @@ <h2 id=css-qnames><span class=secno>4. </span>CSS Qualified Names</h2>
     </dl>
    </div>
 
+   <p>The syntax for the portion of a CSS qualified name before the local
+    name is given below, both for qualified names that allow wildcard
+    prefixes (<code>wqname</code>) and for qualified names that disallow
+    wildcard prefixes (<code>qname</code>). (The syntax uses notation from
+    the <a href="http://www.w3.org/TR/CSS21/grammar.html">Grammar appendix of
+    CSS 2.1</a> <a href="#CSS21"
+    rel=biblioentry>[CSS21]<!--{{!CSS21}}--></a>):</p>
+
+   <pre><!--
+     -->qname_prefix
+<!-- -->  : [namespace_prefix]? '|'
+<!-- -->  ;
+<!-- -->wqname_prefix
+<!-- -->  : qname | [ '*' '|' ]
+<!-- -->  ;
+--></pre>
+
    <p>CSS qualified names can be used in (for example) selectors and property
     values as described in other modules. Those modules must define handling
     of namespace prefixes that have not been properly declared. Such handling

css3-namespace/Overview.src.html

@@ -289,6 +289,22 @@ <h2 id="css-qnames">CSS Qualified Names</h2>
     </dl>
   </div>
 
+  <p>The syntax for the portion of a CSS qualified name before the local name
+    is given below, both for qualified names that allow wildcard prefixes
+    (<code>wqname</code>) and for qualified names that disallow wildcard prefixes
+    (<code>qname</code>). (The syntax uses notation from the
+    <a href="http://www.w3.org/TR/CSS21/grammar.html">Grammar appendix of
+    CSS 2.1</a> [[!CSS21]]):</p>
+
+  <pre><!--
+     -->qname_prefix
+<!-- -->  : [namespace_prefix]? '|'
+<!-- -->  ;
+<!-- -->wqname_prefix
+<!-- -->  : qname | [ '*' '|' ]
+<!-- -->  ;
+--></pre>
+
   <p>CSS qualified names can be used in (for example) selectors and property
     values as described in other modules. Those modules must define handling
     of namespace prefixes that have not been properly declared. Such handling