here Good on those school heads. Pushing the boundaries is of course what the teenage years is all about, but there are boundaries and then there's vagina. I think it's right to draw the line - preferably more than an inch below the knickers.
I find this article odd. The journalist compares teenaged girls flashing their fanjos in a beltskirt to the wearing of a kipper tie. Did he forget to switch his brain on before writing? 
He also drew a comparison with the behaviour of real, human children and those featured in The Beano. I think the answer to the above question is 'yes'.
IMO the ban is a good idea but a better approach would have been to hold a school-wide discussion on the sexualisation of our culture and the ramifications for teenaged girls who are choosing to wear these beltskirts. I'd hope that that would get the girls to think more about the choices they make - if not now, then a few years down the line.