Here's a link to a parental conduct agreement that every player's parent must sign and submit. It's from the local kids rec league in which I used to be active, both as an official and as a Board member. The league gives jackets with the league's logo on it to all Board members so that parents will know that it's a Board member with authority who is monitoring each game. This league usually has about 1200 kids in it in grades 3-12.
http://www.tigardbasketball.org/docl...%20parents.pdf