VMS Help CMS, ANNOTATE, Qualifiers, /GENERATION[=generation-expression]  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Specifies a particular generation of the element to be annotated.
    If you omit /GENERATION, CMS annotates the most recent generation
    on the main line of descent.

    The history contains a description of every generation of the
    element, including those created after the specified generation.
    (Generations created after the specified generation are not marked
    with an asterisk.)