"Hanky Code" for chastity enthusiasts

So, in the gay community, there is (or at least was) a bit of a "Hanky Code" to help identify one another.  Well, I just saw this article about "Feral Cat Hats" and thought it would make a great Hanky Code for chastity belt enthusiasts.  Maybe we'd clip the right ear instead, or maybe fold one over and pin it down!