What i want to know about my topic

I want to know why dress codes are being restricted, because there are some on the dress code i really dont understand why. I want to know who the person is to decide the dress code...is it the principle or do the teachers have a meeting to decide what should be a dress code. What are common punishments for violating dress codes?....Why cant we wear pajama pants to school?....Why cant we wear hats or anything like that at school?....Why cant we wear sunglasses or stunna shades?....Why cant we wear booty shorts to school?