We have a problem in that someone is getting mail from several library related lists, including ours, yet is not subscribed to any of them and she is very upset about it. The best we can figure out is that someone is forwarding the material to her, so we are looking for common subscribers on AUTOCAT, PACS-L, and LIBPLN-L. This is a very tedious job done "manually." My question is this: does anyone out there in Listowner Land know of a program which will compare different text files and give a report as to the exact matches in them? It can be a program for UNIX, VAX, VM/CMS, or DOS. One or the other of us should be able to use it. Any advice is welcome as the prospect of comparing large subscriber lists for common subscribers is a bit daunting. Douglas Winship Austin, Texas [log in to unmask] Secondary AUTOCAT Listowner