High school should be a little bit like University except mandatory attendance until you are 18. The Province forces attendance until 16 y/o I think. As for uniforms, it is part of some schools (religious, private) and part of the school rules. You go to the school (or your parents make you go there), you wear the uniform as defined.

back to 'like university', things like phones should not be used in class, but during breaks and lunch periods, why not? I don't see how anybody would ban its use for recreation.