Amen, Tootler! The train of thought leads me to remember that the last school I taught in, a wonderful community of learners, decreed that all teachers must post their classroom rules in a prominent place, ideally devised by the students. Since I taught all 350 of the students, the list would have been impossibly long, so we would spend a few minutes the first session of the school year brainstorming what behaviours would work best to make the class function. At the end of the week, I invariably posted this:

Be safe
Be kind
Try your best
HAVE FUN!