VMS Help CMS, DIFFERENCES, file, Qualifiers, /SKIP=number-of-lines  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Indicates the number of lines at the beginning of each file (or
    generation) that are to be ignored during the comparison of both
    files. You must specify a nonnegative integer value indicating the
    number of lines to be ignored.