Putting this conversation in the LC thread where it belongs:
This is a very nice rule. But the problem is that it’s not complete. It definitely identifies barbers, but I’m not sure it’s perfect at identifying non-barbers. There are lots of non-stylists that I would consider crappy barbers that neither wash your hair nor use a razor and hot lather.
Nonetheless, next time I get into a debate about whether someone is a barber or hair stylist, I’m definitely going to have this criterion in my back pocket and be prepared to use it.