I went through this issue a few years back on my Football crew. My umpire over the course of the summer got an entire arm mural on his left arm. He did two tours of Afghanistan in the Marine Corps. All of the graphics have some meaning to him and are symbolic of his time in country. I will admit, I had some question regarding the tats. He brought up the issue and said he would wear a sleeve if I wanted him to. Personally I don't care, but my question was how would he/we, we are a team be perceived when coaches and administrators saw his tats. Keeping in mind in Indiana our postseason depends pretty much on our vote from the coaches. I inquired with some administrators and coaches I know, and got mixed results.
In the end, I told him not to cover them up. He's part of the crew and we took him, so the tats come with him. I don't think it has had any effect on our coaches vote. He's becoming a pretty good official, and in the end, I think that's all anyone is really interested in.