In a previous life, we consistenly modified SYSPROF EXEC to conditionally access 319 and 31A (and 19F). If they were missing: no prob, and no error. But most users got them. We then plunked various third party packages (or stubs) onto these disks.
The value of this was that users might trash their PROFILE EXEC (which users are prone to do on any platform) and still get our standard disks, and yet these "standard disks" were not in DCSS so that small changes were much easier, as Mike Coffin suggested. -- R; <><