VMS Help EXCHANGE, RENAME, Qualifiers, /SYSTEM  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /SYSTEM
       /NOSYSTEM

    Controls whether the RENAME command renames files that have the
    file type SYS. These files are usually files necessary for the
    operation of an RT-11 system. Only RT-11 volumes handle SYS files
    in this manner.

    The default is /NOSYSTEM; the RENAME command does not rename an
    RT-11 file with the type SYS, whether it is matched by a wildcard
    specification or is named explicitly. EXCHANGE displays a message
    when it skips an SYS file during a rename operation.

    EXCHANGE handles files with the file type BAD in a similar
    manner; that is, the rename operation skips BAD files. However,
    EXCHANGE does not warn that BAD files are being skipped, and the
    /SYSTEM qualifier has no effect on BAD files. To rename a file
    with the type BAD, specify the file explicitly instead of using
    wildcards.