There is a very important use of minraising in both tournament and ring play. Although some might consider it 'colluding', the minraise, when used three times within 10 minutes, is a signal to players that the minraiser is a complete donkey. If you notice someone minraising three times within 10 minutes, know that they are a donkey but keep quiet, because it is a secret signal. You don't want to get banned for colluding.
If you are a complete donkey, you may use this play to secretly tell other players that you are a total donk. It is considered polite to use this to let others know you are a fish because it makes it easier for the experienced players to relieve you of your chips more quickly, thus reducing the rake the casino takes as your chips are distributed among your opponents.
like taking rake, so they may ban you if you are caught using the "3 minraise in 10 minutes" collusion tactic. So stay quiet while applying this and you will be able to let your chips slide away from you peacefully and without conflict.