If they make the issuing of a license conditional on their rules, which they do, then you need to abide by them. This is how their anti-doping rules work. That they've the time to think about and create rules on tattoos tells you all you need to know about their thinking.
If they make the issuing of a license conditional on their rules, which they do, then you need to abide by them. This is how their anti-doping rules work. That they've the time to think about and create rules on tattoos tells you all you need to know about their thinking.