Did Nat used to have a tattoo?

I was just wondering. I saw this picture and I'm just wondering WHAT is on his arm? I saw these marks in the Holler Till You Pass Out music video as well but the vid isn't clear enough to tell what it is.

So, if it's a tattoo it's definately gone now. Maybe he had surgery to get it off?

Maybe it's just something drawn on his arm in marker, I'm not really sure. What do you guys think?