It is illegal but so far nobody wants to raise an issue with it because it's a school that has a lot of govt officials, diplomats, expats, and businessmen sending their kids there. No one wants to risk stinking their own reputation by raising an issue.

As for "how", apparently if someone accidentally snaps a picture of those kids riding things they shouldn't be, anytime, and a school disciplinary officer sees it, anywhere, he can give out the warning. Has done so a few times actually.

The rationale of the rule is that vehicle operation is something not befitting the image of a student, especially a student at this (supposedly) prestigious school.

Suffice to say the damn rule made me apprehensive of riding in a friend's car for a while, and of the idea of getting my own license when I became of age.

When I decided to ask the school about the apprppriateness and legality of the rule (as an alumnus), they said "we are disappointed in you. You were a great student. We did not expect you to become someone who tries to force us to change our ways of life." That said, unless you grow up to become a nationalist or a right-winger, you are a disappointment to them, so maybe even without this vehicle use thing I'm still a disppointment to them anyway.

This story sounds absurd but yes it is supposed to be this absurd.

I still pass by this school many times as it's on my way to work. I wish I could tell those kids and new parents who might not be aware of "the system" something they should know ...