I think first you need to post the rule word for word in the forum. Next you need to mention whether or not this is a public school or not. As another asked where was the car? What the car parked on a public street or in a school parking lot? If the car was parked on a public street then I doubt there is anything anyone can do about it and the rule will not apply. If the car is on private property then you might have an issue. Again, you really have to know the facts before you can give proper advice. I have yet to see where a public school at least in the area I live in has closed their outside basket ball courts or stopped the students from arriving early and parking their cars, but that is my area and my high school and things are different in different areas. I have never seen it happen in Chicago either. I have seen assigned spots for teachers in parking lots where students were not allowed to park. I have also seen hangers assigned to students for parking purposes at larger high schools. As I mentioned things are different in different places.And your proper advice is.... what?
So the proper advice is going to depend on the circumstances that apply to the area you live, your High School, the actual rule, and reason behind why they have it.
Jason