Terry, please UV your El San Juan chip! I can't find the thread but Jill and I would be VERY interested if you are able to detect any UV barcode-like marks on your chip! I have them on my cancelled ESJ Chipcos and Jill has them on some unknown Harrah's Chipco's. The curveball part of the barcode mark is that all our barcode chips were in the possession of the Caro Co. It would be very (!!!) interesting to us if your chip had them and was from a different source than Caro!