VMS Help SET, AUDIT, Qualifiers, /LISTENER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /LISTENER=device
       /NOLISTENER

    Specifies the name of a mailbox device to which the audit server
    sends a binary copy of all security audit event messages.
    Users can create such a mailbox to process system security
    events as they occur. For a description of the message formats
    written to the listener mailbox, refer to the Audit Analysis
    Utility documentation in the OpenVMS System Management Utilities
    Reference Manual.

    Use the SET AUDIT/NOLISTENER command to disable a listener
    device.