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

       /DELETE[=ALL]

    Deletes ACEs according to the following rules:

    o  The expression /ACL=aces/DELETE deletes the named ACEs.

    o  The expression /ACL/DELETE deletes all unprotected ACEs.

    o  The expression /ACL/DELETE=ALL deletes all ACEs including
       protected ACEs.

    o  The expression /ACL=aces/DELETE=ALL deletes the existing ACL
       (if any) and create a new ACL with the ACEs specifies on the
       /ACL qualifier.