The OASIS XML Catalog document type

The OASIS XML catalog is a document describing a mapping between external entity references or URI's and locally-cached equivalents. You can read more about using catalogs in <oXygen/> here.

Association rules

A file is considered to be an XML Catalog document when it has the following namespace: urn:oasis:names:tc:entity:xmlns:xml:catalog or when its root element name is catalog.