I just stumbled on this by chance. I was scanning the UV light over a few racks of soon to be obs $1 Luxors and had a rack of Boulder Station chips nearby. I notice that half of them showed really bright fluoresence while the others showed nothing. I put the light on the faces.

On one type, the inlay area lights up and there is a security code 'BJ' in the center. The rest of the chip is completely dark (no reaction)
On the other type the edge markings and 'dashes' on the face light up. The inlay and rest of the chip is completely dark. Needs a separate TCR listing IMO. BJ security code chips must be newer.

I cant post a pic at the moment as I dont have a plug in UV lamp. Jim Follis, what do you have???