Steve,
Have you ever seen a chip marked "Poker Room".
Horseshoe WSOP $2.50 chips come to mind. FQ's and other casinos have had them also.
Chips marked this way are not playable on the pit tables and casino cages are not supposed to cash them. (Some will).

Only the poker room cashier is supposed to cash them. They are almost a thing of the past.
BTW the Frontier $1 is a Christy Jones H&C. Tells you how long ago they had Pan.