It sound like you have little programming experiencing so why not go really low tech and use Microsoft Excel: Concatenate the subscribers from REVIEW ALL output of both lists, copy and paste it into Microsoft Excel, Divide it into two columns by selecting Data | Text to Columns and using the Text to Columns Wizard Once in two columns, you can delete either the names field or the email address field and remove duplicates by: Clicking anywhere in the data area and selecting Data | Filter | Advanced Filter from the menu. Check the Unique records only box and Click OK. This hides all the duplicate rows. Highlight the slimmed-down data area. Copy/Paste the data to a new location. It's easier to program and run with it, but this works, needs no programming knowledge and the whole process takes about 5 minutes. Esther Ms. E. Feldman Director, Information and Technology Services The Lookstein Center, Bar-Ilan University tel: +972.35.35.49.80 www.lookstein.org -----Original Message----- From: Hal Keen [mailto:[log in to unmask]] Sent: Wednesday, December 27, 2006 01:18 To: [log in to unmask] Subject: Re: Subscribers to both lists > 2006/12/26, Hal Keen <[log in to unmask]>: > > Easiest low-tech way to do this is to concatenate the subscribers from > > REVIEW ALL output of both lists, hand-snipping out everything else, and dump > > the whole thing into a sort. The MS-DOS interface, or "Command Prompt" > > accessory on Windows, has a sort built in. > > And then use the Windows equivalent of uniq -d. Alas! I don't know of one, which means the next step would be reading through the whole list, looking for duplicates. But uniq -d would fail to catch the very likely case in which the same address is subscribed to both lists, but the name given was different. And, of course, if the person (identifiable by name) is subscribed to both lists but with different addresses, they might not be spotted at all. Looks like programming is seriously better, all around. It should be possible to write something that catches anyone who is subscribed to both lists, with either the same name OR the same address. Again, Perl is the obvious choice, if you've got it. I have had two different subscribers who happened to have the same name. Don't know any obvious way to distinguish such a case, except happening to know the subscribers. But any LISTSERV-based solution, which is what Doug was originally hoping for, would almost certainly only recognize subscriptions using the same address. Hal