">Java API for XML
 Processing Specification</a>.</p>

 <p>Resource locations can be specified either in-line or in
 external catalog file(s), or both.  In order to use an external
 catalog file, the xml-commons resolver library ("resolver.jar")
 must be in your classpath.  External catalog files may be either <a
 href="http://oasis-open.org/committees/entity/background/9401.html">
 plain text format</a> or <a
 href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">
 XML format</a>.  If the