The mini was once a common dress code for all kinds of organizations and professions (waitresses, choir, nurses, FHA, and even and military uniforms). Private schools didn't require the skirts to minis; however, it wasn't forbidden, so naturally it became part of the dress code. Sadly, besides cheerleaders, I'd say that minskirt has largely become extinct as a uniform; I guess they figure it takes away from the seriousness and professionalism of the person wearing it.
But I'm proud to say we're keepin' the flame alive on Retrospace. Note that we are going to bypass stewardesses and cheerleaders as theirs have warranted multiple posts each. Plus, we'll skip the French Maid as that has already been covered. I have a plethora of choir girls and other school related uniforms (most of these images come from old yearbooks). I'm a bit lacking in the nurse and waitress department. Any vintage photos in those domains would be much appreciated. Enjoy.
I guess the girls tennis outfit would also qualify as uniform miniskirt that has stood the test of time. Maybe a tennis Miniskirt Monday is in our near future.