VMS Help RTL Routines, LIB$, LIB$RESERVE_EF, Argument  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 event-flag-number

    OpenVMS usage:ef_number
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Event flag number to be allocated by LIB$RESERVE_EF. The event-
    flag-number argument contains the address of a signed longword
    integer that is this event flag number.