I go to a catholic school too and we have strict dress codes here. But they don't really make us wear shorts under our skirts. However, we have to keep our skirt 3 inches below our knees, wear skin-toned bras, absolutely no makeup or accessories, and to tie your hair up at all times, even if it's dripping wet.
I think super strict dress codes like that are absurd and useless. Regarding your case, I think it's fine for them to make you wear shorts if you have skirts above your knees, you know, for modesty.
But to make you wear shorts under a goddamned long skirt? That's ludicrous.
i wear one even if im not required. It makes it easier to move and i dont have to be cautious of my actions all the time. and based from personal experience when my skirt went up when i go out from a public transpo (car), not a good idea... lol
It's to protect your dignity in case of the wind and the boys that like to lift up girls skirts probably. I went to a catholic school for a while. There rules are the worst at times, good luck having to endure it all.