This specifies the base directory or name entry to use when redirecting
 the synonym mapping link from the old to the new node name.

     SYNONYM_DIRECTORY syn-dir-name

 The links under this directory are used to map Phase IV synonyms to
 their respective node names.  These directories are used only for the
 DECdns directory service.

 If not specified, the default synonym directory is used.  This default
 can be displayed or changed using the SHOW or SET DEFAULT commands.

 For more information, please refer to the NAMES_AND_DIRECTORIES topic.