I also once saw a boy being led from the headmistress’ office by the senior master; judging from his demeanour, he had been caned on his bottom. The school was mixed, but I do not believe that girls were caned. Very occasionally, though, a girl would be slippered by the headmistress; on one occasion she felt the need to announce this fact to the school at assembly.
A researcher looking through the punishment book for this school would therefore get the impression that CP was used only occasionally in this school.