That’s very common for guys in a certain fraternity. Half the team in 1989 had that. Definitely a painful initiation which also includes getting your ass kicked (according to a former co-worker of mine who was in the Wyoming chapter).This is not meant negatively at all:
Watching the replay just now, I noticed (8:22 left in the 1st half) that BJ Green has fairly large symbols burnt into his left upper arm. That causes really serious pain, and this is one tough man.