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

       /LIMIT=n

    Optional.

    Maximum number of copies of the requested service allowed to run
    on the system. If the maximum number is reached, any additional
    requests for the service are rejected.