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

    /CHANGED=(source1, source2,...)

    Directs MMS to treat only the specified sources as having been
    changed, regardless of their actual modification times. No date
    checking is performed at all; MMS simply rebuilds any targets
    that depend on one or more of the specified sources. This
    qualifier affects the behavior of MMS but not the execution of
    action lines.