Actually, I tried that before I posted, this is what it says in that area:
Edit Avatar
Your Current AvatarNo Avatar Specified Avatars are small graphics that are displayed under your username whenever you post.
Do not use an avatar
Note: if you have a custom avatar selecting this option will delete it.
There is no way to "uncheck" the "do not use an avatar button". What can others see?
Looks like the signature part is working!