Usual RFC link style

Author: Girgias

reference/filter/constants.xml

@@ -500,7 +500,7 @@
    <listitem>
     <simpara>
      Validates whether the <acronym>URL</acronym> name is valid according to
-     <link xlink:href="&url.rfc;2396">&url.rfc;2396</link>.
+     <link xlink:href="&url.rfc;2396">RFC 2396</link>.
     </simpara>
     <variablelist xml:id="filter.constants.validation.url.options">
      <title>Available options</title>