I went to a Catholic Boarding school with my twin sister. It was run by a group of nuns along with a number of lay staff. In general, it was a loving environment but was rather strict.
During the day, we wore our school uniforms and in the evenings and at weekends we also had a sort of uniform. A young nun called Sister Claire ran our dorm, and she was quite easy going, almost ignoring the rules on underwear and knee-length socks, especially in our weekend clothes. She would, however, smack our legs with a ruler if we got rowdy.