I have spent a long period of time living in South Africa.
School uniforms in SA are very expensive and in most cases, can only be obtained from specialist school outfitters who exploit the general public. My grand-daughter attended a private school in SA and her uniform was ridiculously expensive. The rules for uniform, personal appearance etc. were strictly enforced. Skirt lengths had to be no shorter than one hand width above the knee, measured when the child was kneeling.
When we returned to Norfolk just over a year ago, we were very happy with the fact that uniforms are easily obtainable through most local supermarkets. At Long Stratton High School we have seen that a lot of the girls seem to be allowed to wear copious amounts of make-up, tangled waist length loose hair and one or two girls get away with wearing very short skirts.
I personally feel that outright bans are draconian.
Schools should enforce hem, make-up and hair regulations and hold frequent inspections. All girls (and boys) need to be taught to respect regulations within the school environment. Banning is the lazy alternative and drives problems elsewhere.