I wouldn’t try make formal registeration form’s.
Those planning doesn’t belong in any public forums. There is rules, sizes, protections, copyright stuff. Its in coding, you should suggest ideas about what it should have inside.
Game can’t have nonprotected links to forums or backward from forums to game as player logged in.
Larger picture having whole support inside game as well chat system replan would be useful.
But its possible and makes a lot bigger whole game.