VMS Help DELETE, file, Qualifiers, /BY_OWNER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /BY_OWNER[=uic]

    Selects only those files whose owner user identification code
    (UIC) matches the specified owner UIC. The default UIC is that of
    the current process.

    Specify the UIC by using standard UIC format as described in the
    OpenVMS Guide to System Security.