As a matter of fact, it is the only $0.12½¢ chip I have ever seen that I can recall. Ergo, unique to me. But one must keep in mind, that I am a relative newbee compared to at least 4422 other chippers and readily admit that there are a lot of chips "unique" to me but not to others.

Next time I will try to be more precise and state that it is "unique to me" and therefore might pass the test of correctness to the chipboard patrol.