I don't understand why people feel the need to label fish. First of all, they rarely stick around for very long so the effort you put into labeling them is usually wasted beyond your current session, and you can just look at their VPIP/PFR to know they're a fish anyway. Same thing with taking notes on fish like "limped pre with J8s and c/c 3 streets on T8xxxx". I fully expect fish to do this so it's not noteworthy, save your notes for regs or fish taking lines that you wouldn't expect.

Categorizing regs is more worth your time imo, but you want to use information you can't get from just glancing at stats. If a reg turns into a calling station vs you postflop, if and how they defend their blinds vs you, if they bluff in bad spots, stack off pre light etc.