Good question.
We've always had a problem with anonymity, but since I've finely caved into the idea of registration, I would like to try to put that behind us now.
I don't think that there is any problem with using a handle like Loco112,or (just looking back over this thread) Southern Steam, or even RogerDelafield, but I would like to ask that you do identify yourself in your profile.
If you have a valid reason for not identifying yourself, say you work for a RR and you've been asked not to post here, then you probably shouldn't be posting here in the first place.
Don