org.eclipse.vex.core/plugin.xml

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.4"?>
<plugin>
   <extension
         point="org.eclipse.wst.xml.core.catalogContributions">
      <catalogContribution
            id="XInclude">
         <uri
               name="http://www.w3.org/2001/XInclude"
               uri="xsd/XInclude.xsd">
         </uri>
         <system
               systemId="http://www.w3.org/2001/XInclude.xsd"
               uri="xsd/XInclude.xsd">
         </system>
      </catalogContribution>
   </extension>

</plugin>