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

    Output File Qualifier

    Creates a new version of a file if a file with an identical
    specification already exists at the location to which the file is
    being restored or copied. The new file is created with the same
    name and type and a version number one higher than the highest
    existing version.

    By default, BACKUP does not restore a file with the same file
    name, file type, and version number as a file that already exists
    in a directory. Rather, BACKUP issues an error message and does
    not restore the file. The /OVERLAY and /REPLACE qualifiers also
    override this default, but produce different results than the
    /NEW_VERSION qualifier.

    Note that when copying or restoring files using the /NEW_VERSION
    qualifier, files are processed in decreasing version number
    order and are created in ascending order. The result is that
    the version numbers are inverted.

    Because this qualifier causes version numbers to change, do
    not use the /NEW_VERSION qualifier with the /COMPARE or /VERIFY
    qualifier.