This specifies the base directory or name entry to use when accessing
 reverse address mapping links (also called back translation links) in
 the specified directory service.

 The links under this directory are used to map NSAP values to their
 respective node names.  These are used only for the DECdns directory
 service.

 See the MAIN_MENU NAMES_AND_DIRECTORIES REVERSE_ADDRESS_MAPPING topic
 for more information on these directories.