Using the root-catalog.xml file to configure catalogs
Specifying catalogs is now easier in DITA CMS 4.1.
The DITA CMS uses catalogs to locate the DTDs that define the DITA elements and objects used in your system. In DITA CMS 4.0, the master-catalog.xml catalog was added to the oXygen editor. This catalog was specific to a user's current server and Content Store, so users had to configure the catalogs again if they changed server, Content Store, username, etc.
DITA CMS 4.1 introduces a new catalog to simplify this process. This catalog, root-catalog.xml, is stored outside of the user's repository and dynamically points to the master-catalog.xml catalog in the Content Store currently used.
The advantage to this method is that you need to configure the path to the root-catalog.xml only once, when you set up the DITA CMS Eclipse Client.