2.56. SubCatalog *global*
Allows definition of a catalog which shares most of the characteristics of another catalog. Only the directives that are changed from the base catalog are added. The parameters are: 1) the catalog ID, 2) the base catalog ID, 3) the directory to use (typically the same as the base catalog), and 4) the SCRIPT_NAME that will trigger the catalog. Any additional parameters are aliases for the SCRIPT_NAME.
The main reason that this would be used would be to conserve memory in a series of stores that share most of the same pages or databases.
SubCatalog sample2 sample /usr/catalogs/sample /cgi-bin/sample2