As a commish is it true you can keep people from returning from season to season if you do not want them in your world?

I was always informed that you don't HAVE to let anyone in your world if you don't want them there anymore. IF they are just a pain in the ***, wait until the end of the season and not allow them to return.

I am really only asking this because I am having a discussion with another owner that doesn't seem to understand what I am trying to tell him. I am telling this owner to STFU in the world and stop arguing because it can cost him the right to stay. He thinks that they can't stop him from returning but in a sense they can because I have always been told by Admin that if they are not breaking the fairplay guidelines that I have to wait until the end of the season to remove them since they can't remove them in mid season for "nothing".