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

       /MERGED[=n]

    Specifies that the output file contain a merged list of
    differences with the specified number of matched records
    listed after each group of unmatched records. The value of the
    parameter n must be less than or equal to the number specified
    in the /MATCH qualifier. By default, the DIFFERENCES command
    produces a merged listing with one matched record listed after
    each set of unmatched records (that is, /MERGED=1). If the
    /MERGED, /SEPARATED, or /PARALLEL qualifier is not specified,
    the resulting output is merged, with one matched record following
    each unmatched record.

    Use the /MERGED qualifier to override the default value of the
    parameter n, or to include a merged listing with other types of
    output.