The XML catalog mechanism enables files to be retrieved from local folders, thus increasing the overall processing speed, as well as improving the portability of documents—since only the catalog file URIs then need to be changed. See the section How Catalogs Work for details.
Altova's XML products use a catalog mechanism to quickly access and load commonly used files, such as DTDs and XML Schemas. This catalog mechanism can be customized and extended by the user, and it is described in the section Altova's XML Catalog Mechanism. The section Variables for System Locations list Windows variables for common system locations. These variables can be used in catalog files to locate commonly used folders.
This section is organized into the following sub-sections:
For more information on catalogs, see the XML Catalogs specification.