Something else to consider on the employment/dress code/tats covered issue. There are a lot of tats that make political or religious statements too, another no-no in a customer-service related business in which you are dealing with the public. An employer can tell me not to wear a shirt to work that says "Vote Obama!" etc., it is similar with requiring tattoos be covered. They cannot really take them on a case by case basis, there must be a general rule for all.

When I was a waitress I had to keep my hair a certain way and dress a certain way. It isn't discrimination, it's just that business's code. If I didn't want to dress that way or keep my hair that way, I was free to look for employment elsewhere that didn't require it. I think it is the same with businesses who have a "dress code" that includes body art displays.