handle

    OpenVMS usage:identifier
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by reference
    Identification of the AST request to be canceled. The handle
    argument uniquely identifies the request and is returned when the
    $SETCLUEVT service is called.

 acmode

    OpenVMS usage:access_mode
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Access mode of the cluster configuration event to be canceled.
    The acmode argument is a longword containing the access mode.

    Each access mode has a symbolic name. The $PSLDEF macro defines
    the following symbols for the four access types:

    Symbol         Access Mode

    PSL$C_KERNEL   Kernel
    PSL$C_EXEC     Executive
    PSL$C_SUPER    Supervisor
    PSL$C_USER     User

 event

    OpenVMS usage:event_code
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Event code indicating the type of cluster configuration event for
    which an AST is no longer to be delivered. The event argument is
    a value indicating which type of event is no longer of interest.

    Each event type has a symbolic name. The $CLUEVTDEF macro defines
    the following symbolic names:

    Symbolic Name      Description

    CLUEVT$C_ADD       One or more OpenVMS nodes have been added to
                       the OpenVMS Cluster system.
    CLUEVT$C_REMOVE    One or more OpenVMS nodes have been removed
                       from the OpenVMS Cluster system.