I interpreted it as "Account Name != Nickname", so my script isn't sending the current nick (which may change) but an "Account" name stored elsewhere.
Hasn't failed me yet on various networks that support SASL, so I'd assume they're not the same in general.
Most of those networks (if not all, would have to check) have a separate numeric (raw 330 if I'm not mistaken) to return such an account name. First saw this with Quakenet (where the Nick is not tied into the account) and others automagically worked by handling 330 (even though they use NickServ or similar, which is essentially and historically treated like an account); but that could be a coincidence.
