Library /sys$common/syshlp/tcpip$ucp_help.hlb SHOW, HOST, Qualifiers, /DOMAIN  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /DOMAIN=domain

    Optional. Default: Name service domain.

    Domain to be used by the local host. However, the definition of
    the domain name is valid only during the execution of the current
    SHOW HOST command. The BIND request is sent to the specified
    domain.