> I recently inherited maintenance of a list and web subscription interface. I
> am noticing that since ListServ is case-sensitive, users are actually
> allowed to subscribe twice or more, depending on case variations.

This is why I prefer people to send mail subscriptions.  Even if it's just
a blank email to list-subscribe-request, you can be sure that it'll actually
pick up the correct email address.  Trusting users to know what their email
address is is a folly in large organisations.  First hand experience.

Have fun,

Paul