Administration > Environment Variables > APTCATPATH — Specifying Paths for Catalog Files
  
APTCATPATH — Specifying Paths for Catalog Files
Specifies the paths for the set catalogpath command, which is the list of path names to directories used for locating a catalog file. The initial default directory is the Arbortext-path\doctypes directory. You need to include this default (for example using %D) in your search path for Arbortext Editor to work correctly.
The catalog path can also be set on the File tab in the Preferences dialog box for permanent default settings. Add the path name to the list in the Catalog Path field.
For example,
set APTCATPATH .:~/doctypes: %D
Two symbolic parameters (%H and %D) may be specified as part of the search path.
* 
The append_catalog_path function appends or prepends paths to the existing catalog path. The results of this function will override the contents of the APTCATPATH environment variable.
If you are implementing a custom document type, you should consider using the Arbortext-path\custom\doctypes directory to load it automatically upon startup.