Un-used chips like the ones shown are notched samples that were kept by the manufacturer (Burt Co.) and also used as examples sent to the distributors as examples of the order. They were never used, were notched to prevent being cashed in and should be considered as RARE manufacturing samples of an order. That have to be UNUSED! Otherwise they are just cancelled chips. Several styles of cancelling were used for samples depending upon what period they were manufactured in.