As of now, there is no known use for the clothing/tattoo codes, mainly, because, well, nobody that I know has ever heard of one existing :P
Hopefully, these codes will come into play in a future update, or possibly, the will be given out by the GM's, just like they did in that Test of Strength event they had awhile back (only the codes they handed out for that was for gold. Yay, 150 gold >.>)
Hope that helped
