Okay, this is kind of a stupid question, but I'm not sure. On one's own forum, if there's a member an administrator is having problems with, yet they aren't being a nusiance enough member to the board to be banned, can that administrator add the person to their foes list instead of straight out banning them? Or how does it work when you have your own forum? If I need to explain myself properly, let me know please.
It is physically possible to add a member to your foe list when you are an administrator but really i think as an admin you should never block an user by adding them to your foe list. Part of being an admin is putting up with people you dislike but you still need to be able to read everything. If a user is causing you annoyance, no doubt they are annoying other users and therefore you really need to see what is going on and how that user is behaving.
At the end of the day, as an admin you can ban who you want for whatever reason. It is always better to grit you teeth and put up with the user but that option is always there. It is like shops. The allow you to work in but they have the right to disallow anyone they want for any reason they want. It is their property. Like your house, you can choose who you want to come in your house and who not.