One one hand I want civil liberties, on the other, I understand not wanting a distraction from classes in the form of boobs hanging out or hateful shirts or cursing. Sometimes it's nice when people label themselves so you know who to stay away from

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No, children need to learn how to dress and how clothing can affect the way they are percieved by society. Most people learn their social skills in school, and dressing well is a social skill.
If uniforms are to be enforced, they must give girls/women the option to wear pants. Forcing them to wear skirts limits their movement and independence as individuals.
There is tremendous pressure to conform to popular groups and expensive clothing, however, school uniforms do not eliminate this. Anyone who's been to a uniform-wearing school knows people have other ways of ostricising and parting from each other - it's not the clothes, it's part of human social interaction. Even jewelry, hairstlye, physical beauty, or parental jobs can be factors. The kids are going to need to learn how to stand up to the pressure to buy and conform eventually, and when you're young and supervised by school and parents is the best and safest time to learn these things. There's risk showing up at school and being made fun of for having bad clothing (due to poverty or lack of knowledge or care), but there's more risk with showing up at an important job interview or social event and not knowing what to wear, or why people care about what you're wearing.