A promenade get dressed code - mandatory or now not?

An Illinois Highschool has a 21-web page-lengthy get dressed code (rather?) forbidding "excessively tight" attire, attire which might be better than 3 inches above the knee, and greater. long tight prom dresses

My difficulty with this strict rule e-book is that solely two pages out of the 21 are directed against younger adult males... ~ Jo