Eh idm them being posted in the thread LOL.
I got really confused since I was about to answer and I was like where these posts at.
To answer your question:
I have made it so when you register your account you cannot have special characters in your name however, underscores don't qualify as a special character.
I thought I specified that in the post.
I'd rather people didn't use underscores but yeah.
So yes to underscores, no to minus symbols.