VMS Help SHOW, SECURITY, Qualifiers, /EXPIRED  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Modifies the time specified with the /BEFORE or the /SINCE
    qualifier. The /EXPIRED qualifier selects files according to
    their expiration dates rather than by the backup, creation,
    or modification date. (The expiration date is set with the SET
    FILE/EXPIRATION_DATE command.) By default, files are selected
    according to their creation date.