This form allows you to set preferred values to use for various defaults,
 such as the reverse address mapping directory name to use for a particular
 directory service.

 It is particularly useful to set these defaults using a DECNET_REGISTER
 initialization command file, so that they will set up automatically
 every time DECNET_REGISTER is started.

 See the MAIN_MENU INITIALIZATION_COMMAND_FILE topic for more information
 about initialization command files.