Specific bans do not have to be mentioned, there are plenty of examples. The biggest one is a player changing their city names to something that is ban worthy, then having their team mates turn them in for it, so they get a non-attackable ban and then they do not address the ban until their red revolts on their cities have ended. I have seen it in many worlds, and I have also cautioned team mates of my own about their city names possibly being ban worthy, because another favorite thing to do is check the attacking players city names and if you find one that could possibly get them banned to end the onslaught of attacks from them, you have every player on your team send in a support ticket about it to get it done.