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

    /FROM_SOURCES
    /NOFROM_SOURCES (D)

    Directs MMS to build a target from its sources, regardless of
    whether the target is already up-to-date. This qualifier affects
    the execution of action lines and the behavior of MMS.

    When you specify the /FROM_SOURCES qualifier, MMS does not
    compare the revision times of the specified sources and target.
    Instead, it executes the action lines in the description file
    necessary to update the target. The /FROM_SOURCES qualifier
    is useful when you want to guarantee that an entire system is
    rebuilt, perhaps for an internal release.

    If you specify the /CMS and /FROM_SOURCES qualifiers on the MMS
    command line, MMS uses the sources found in the default CMS
    library. If you do not use /CMS, MMS uses the sources found in
    the specified directory.

    The /FROM_SOURCES qualifier overrides the /SKIP_INTERMEDIATE
    qualifier.