In the case of that example, you should probably add ".net" after the "WNFF", perhaps in a smaller font (matter of taste). I am also of the opinion that if you're trying to advertise something, it should always go on the back of a shirt, not the front. After all, who's going to stare at your chest long enough to read something?
Whatever the joke is, it went over my head 
Winter league uniforms are absolutely covered with ads.
