Barring a bug (and no such bug has been reported), this can only happen if the file is edited by hand, or (under unix) if the file is corrupted after a system crash or the like. Under VM there have been a couple instances of people putting the LISTSERV code on a R/O disk and the migration procedure failing to erase a REXX procedure that had become obsolete and did not know about the new LIST format. In general you get unpredictable results on VM if you do not put the code on the A disk. Some people do it because of security auditing requirements, but it's not a supported mode. At the very least, it requires manual installation. The auto-install method can't know what special local steps it needs to take to update write protected code, besides in most cases these steps will start with "log in to LISTADM userid" or "call security auditor" or some other action a program can't do. Anyway, this is maybe 2 sites in the network, so I'm only mentioning it for the sake of completeness. Eric