Roy,

John is correct. In this instance, it is the rotation of the H&C that makes the difference. On some chips it will be a different size, a different location or a combination of all of them.

The UV is printed along with the rest of the inlay.

If you have a blacklight you can view the UV marks. I would be interested in you what you find when you view your box of chips. Perhaps you can sort them into piles and let me know if you find a 3rd variation. I personally don't consider minor shifts in location to be a different variety. Usually, the UV mark must be have moved at least 1/4 inch or so.

Greg