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.

    Event-id is returned by PPL$CREATE_EVENT.

 signal-value

    OpenVMS usage user_arg
    type          longword (unsigned)
    access        read only
    mechanism     by value
    Optional user-defined value to be signaled when the event occurs.
    The signal-value argument is an unsigned longword containing this
    value.