Reminds me of the video that I probably saw here of breaking up fights in Japanese school, in that they really don't try to do that and let them work it out on their own. Japan rules
That doesn't seem to make a lot of sense...I mean if you we want kids to behave like adults (taking public transport on their own etc.), then we ought to let them charge each other with assault and face the consequences.
I've heard teachers use phrases like 'schoolyard rules', it's ever been advocated for by someone who I found to be thoughtful.