Beginning in OpenVMS Version 7.3-2, a number of functional
    changes were made to SYS$ACM[W]. In the following descriptions
    of these changes, nonprivileged processes refer to processes
    running in user mode that do not have SECURITY privilege.

    These changes are the following:

    o  Timeout processing

       Timeout processing is now enforced for nonprivileged
       processes. Othe processes can request time processing by
       specifying the ACME$M_TIMEOUT function modifier.

    o  Dialogue mode iteration limit

       Nonprivileged processes are now limited in the number of
       iterative requests they can make in a dialogue sequence of
       calls.