VMS Help RTL Routines, PPL$, PPL$DISABLE_EVENT, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 event-id

    OpenVMS usage identifier
    type          longword (unsigned)
    access        read only
    mechanism     by reference
    Identifier of the event. The event-id argument is the address of
    an unsigned longword containing the identifier.