To specify an ACEE value, the calling program must be running in a system key or in supervisor state. If the ACEE is not specified, the address space level ACEE is used. In either case, the ability to enable the write-down privilege is determined using the IRR.WRITEDOWN.BYUSER profile in the FACILITY class based on the user ID in the ACEE. The FACILITY class must be active and RACLISTed, the IRR.WRITEDOWN.BYUSER profile must exist in the RACLISTed profiles, and the SETR MLS option must be active.