XML Catalog Preferences

To configure the XML Catalog options, open the Preferences dialog box and go to XML > XML Catalog.

The following options are available:

You can also add or configure catalogs at framework level in the Document Type Association preferences page.

When you add, delete or edit an XML catalog to / from the list, reopen the currently edited files which use the modified catalog or run the Validate action so that the XML catalog changes take full effect.

Related information
http://xerces.apache.org/xml-commons/components/resolver/resolver-article.html#ctrlresolver
Working with XML Catalogs