/sys$common/syshlp/helplib.hlb DISMOUNT, Qualifiers, /FORCE_REMOVAL  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /FORCE_REMOVAL ddcu:

    Expels a named shadow set member from the shadow set.

    If connectivity to a device has been lost and the shadow set
    is in mount verification, you can use the /FORCE_REMOVAL ddcu:
    to immediately expel a named shadow set member (ddcu:) from
    the shadow set. If you omit this qualifier, the device is not
    dismounted until mount verification completes.

    Note that you cannot use this qualifier in conjunction with the
    /POLICY=MINICOPY (=OPTIONAL) qualifier.

    The device specified must be a member of a shadow set that is
    mounted on the node where the command is issued.