Just to be sure it's understood - there's nothing wrong with using a pseudonym at mudcat, and I'd recommend it particularly for women in many situations. It's the deceptive use of pseudonyms that's a problem. If you want to change your user name once, that's not a problem. If you want to change it every other week, that's another matter.
It's preferable to be a registered member and to be logged in, but it's not required - as lond as you use a consistent name when posting.

-Joe-