The XML Catalog preferences panel is opened from menu .
The Prefer option is used to specify if Oxygen XML Developer will try to resolve first the PUBLIC or SYSTEM reference from the DOCTYPE declaration of the XML document. If PUBLIC is preferred and a PUBLIC reference is not mapped in any of the XML catalogs then a SYSTEM reference is looked up.
When using catalogs it is sometimes useful to see what catalog files are parsed, if they are valid or not, and what identifiers are resolved by the catalogs. The Verbosity option selects the detail level of such logging messages of the XML catalog resolver that will be displayed in the Catalogs view at the bottom of the window:
If the Process namespaces through URI mappings for XML Schema option is not selected only the schema location of an XML Schema that is declared in an XML document is searched in XML catalogs. If the option is selected the schema location of an XML Schema is searched and if it is not resolved the namespace of the schema is also searched.
If the Use default catalog option is checked the first XML catalog which Oxygen XML Developer will use to resolve references at document validation and transformation will be a default built-in catalog. This catalog maps such references to the built-in local copies of the schemas of the Oxygen XML Developer frameworks: DocBook, DITA, TEI, XHTML, SVG, etc.
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 you must reopen the current edited files which use the modified catalog or run the action Reset Cache and Validate so that the XML catalog changes take full effect.