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

    Combines two generations of an element and creates a single
    file that contains the annotated listing. The parameter on the
    /MERGE qualifier specifies the generation that is merged into the
    retrieved generation. This command creates a file that contains
    the text common to both generations and the changes made to both
    generations. When changes that are not identical are made in
    the same position of the common ancestor, the changes from both
    generations are included in the resulting file and are marked as a
    conflict. By default, generations are not merged.