[Kanji_The_Wanderer]

Do all schools have uniforms? I have seen schools where the guys were all black. Black pants, shoes, and a long sleeve black shirt. The girls wear a white shirt, a black skirt, and a black over coat/shirt. Is this a common uniform? Or is it only for a certain place/region? Did you go to school there and wear these types of clothing?

Are uniforms optional? This has always interested me, and I have never got a good enough answer.