/sys$common/syshlp/helplib.hlb RPC, rpccp, show_mapping, ARGUMENTS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

         host-address
                 The host-address argument is a string binding that
                 indicates where to find the target endpoint map.
                 When accessing the local endpoint map, you can
                 specify what protocol sequence to use (optional);
                 ncadg_ip_udp:

                 When accessing a remote endpoint map, you must
                 specify both a protocol sequence and a network
                 address for the remote system (required); for
                 ncadg_ip_udp:16.20.16.44

                 An endpoint is unnecessary in local or remote host
                 addresses, and the remove mapping command ignores
                 any endpoint specified as part of a host address.