I have a question on this chip scan from the Exchange Club in Beatty, NV. The chip is listed in TCR as N3691. The front side of the chip is for $5.00 but the backside (see below) has this. Is this a cancelling mark? Also, what do the initials represent? I haven't seen any mention of this in the TCR or Campiglia's guide. This newbie would appreciate any help on this chip. Thank you