Some leagues and tournaments invite referees to show cards to coaches, but as has been stated, the LOTG only allows cards are for players, substitutes etc. Coaches can be removed by referees. As for parents, technically, referees aren't supposed to have to deal with them, the coach is. However..... some coaches won't, and some don't do enough. Referees can insist a parent leaves the area or the game will not resume. I've done it several times, and won't hesitate to do it again if need be. Some referees will remove the coach, and that's what we're instructed to so, but in certain situations, that would be to the detriment of the players, and sometimes, the coach isn't all that culpable.
Anytime any of this happens, it is imperative that the referee write a report, both in the online reporting if that particular league has it, and with a supplemental report, sent to league or tournament officials, along with his/her assignor and the association he/she works for. You have to write a report, and make sure as many people see it as possible, so the behavior is eliminated. A name would be nice if you had it, but that team knows who the parent is so the league can find out. Most clubs and most gaming leagues will deal with single bad apple parents, and/or teams of unruly parents. It almost always starts from the coach though. If the coach is abusive, the parents think it's ok to be abusive also. If the coach lays down the law with the parents, and doesn't allow them to scream at referees or to scream instructions, all of this is avoided.
