Silly Prank
I went to a high school where we had to wear uniform Oxford shirts with a front pocket. One year the seniors started goofing around and “pocketing” each other. It was a dumb made-up prank.
Sort of like pantsing, except they’d tear the victim’s shirt pocket off. By the end of the day, a lot of students no longer had their shirt pockets, and half the class was on in-school suspension.