Steve, this was a rule of fairly recent vintage. As I recall, maybe 1993 or 1994. I did short piece on the rule in the Club magazine.

It became required at the same time manufacturers were required to put their identification on all casino chips (which is why we see little hats & canes on PaulSon chips and "BJ"s on Bud Jones chips made recently). The rule wasn't retroactive (existing chips were grandfathered in, so the rule only applied to new orders), and it was some years before the manufacturer-ID requirement was enforced, apparently.

Michael