Brief note on usernames:
Epistemic status: Kidding around, but also serious
If you want to create an account without using your name, I recommend choosing a distinctive username that people can easily refer to, rather than some variant on "anonymous_user".
Among usernames with 50+ karma on the Forum, we have:
I'm pretty sure I've seen at least one comment back-and-forth between two accounts with this kind of name. It's a bit much :-P
You could write that the username is deliberately anonymous in your Forum bio.