I went to some private schools at times, and there were all sorts of rules on dress and manners and such, and to hell with them all.
But the school that really boggles the mind was the George Ford Elementary School in Detroit, where I went for first grade. I have trouble convincing people this was real, but one of the rules was that one had to walk down the corridors in strict single file, and that included taking the corners at a precise 90 degrees. Even in first grade, the school was run like a junior high, with students going from classroom to classroom, so there was a lot of marching. There were frequent assemblies, where we watched movies, usually some kind of government public service stuff about how we were all going to be bombed by the Russians. We had a science class, in which about the only movie I remember was about the scourge of malaria. The school was firmly dedicated to "whole word" reading, such that most students in first grade couldn't read, and we spent so much time on that that we did not get any arithmetic at all - not even counting. It started out with a giant Dick and Jane flipbook which the teacher opened at the head of the class. Run Dick Run. We did have a time learning to read a clock, which I found difficult, because the hands were defined as big and little. According to idiot psychologists, kids that age think of the long hand as bigger whether it is or not. I did not. I thought the short fat hand was bigger than the long thin one. My confusion on this was baffling to the teacher, who was apparently incapable of conceiving that the difference between hands is length. I did learn to read (at home, phonically) and got a watch for my 6th birthday halfway through the year, whereupon I also learned to tell time.
We also had, of course, air raid drills, in which it was obligatory to put your right arm over the head and the left under. To do it in reverse was wrong!
Oh, and there was a rule that if you lived within a mile of the school you were not permitted to bring lunch. You had to go home. The lunch room was virtually empty, but every day my mom had to come to school to walk us home, whereupon we had about ten minutes to wolf down lunch before being walked back. The rule, like all rules there, was inflexible. It did not matter that I was 5 years old and living in a city.