Found these today in my trek across AZ...
What I find interesting is:

1. Aren't these just home game/ common chips?
2. If yes - why would they be notched? (used in a bar or something to keep people from bringing their own from home?)
3. ALL of them are notched... and most of them have a stamp (one side only - and it's just a cheap rubber stamp or something- NOT hotstamp) with a circle and
T/S
3

I am just curious - do/ did / would someone stamp and notch these just for home games? ??????