I stand corrected, everything to the left of the "@" sign is case
 sensitive.  It makes perfect sense if you think about it, which I
 should have done before I posted. :)  On UN*X systems, the usernames
 jimj, JIMJ, JimJ etc... are all unique.  The hostnames, meaning
 everything to the right of the "@" sign are not case sensitive.
 
 The info on the effects of not registering an ":internet" tag is
 still accurate however.  I've appended some commands, and LISTSERV's
 reponses to demonstrate what I was describing in my previous note.
 It may not be the source of the problem we're discussing in this
 this thread, but I thought it still might help someone on the list.
 I'd definitely advise anyone on a Bitnet machine to register their
 Internet host name.
 
 To understand what the following commands illustrate, note that the
 BITEARN NODES entry for JHUVM includes a :internet.JHUVM.HCF.JHU.EDU
 tag.  That's why the "DEL" command found and removed the subscriber
 on the list using the Internet host name.
 
 -jj
 
 ----
tell listserv quiet add jhtest-1 [log in to unmask] Test User
Ready; T=0.04/0.07 00:17:46
* [log in to unmask] has been added to list JHTEST-1.
* Notification has NOT been sent to Test User
 
tell listserv quiet del jhtest-1 testuser@umbc2
Ready; T=0.03/0.07 00:18:11
* TESTUSER@UMBC2 does not appear in list JHTEST-1.
 
tell listserv quiet del jhtest-1 [log in to unmask]
Ready; T=0.03/0.07 00:18:22
* [log in to unmask] has been removed from list JHTEST-1.
* Notification has NOT been sent to [log in to unmask]
 
 
tell listserv quiet add jhtest-1 [log in to unmask] Test User
Ready; T=0.04/0.07 00:18:42
* [log in to unmask] has been added to list JHTEST-1.
* Notification has NOT been sent to Test User
 
tell listserv quiet del jhtest-1 testuser@jhuvm
Ready; T=0.03/0.07 00:18:51
* [log in to unmask] has been removed from list JHTEST-1.
* Notification has NOT been sent to [log in to unmask]