Happy Holidays from the ChipGuide. OG means Old School and for the ChipGuide, old school means just casino chips, the way that Greg Susong had it. I've heard from some collectors that want to see just chips from casinos on the ChipGuide. Leave out all the other stuff and leave out the advertising chips and all the items that are not from casinos. That is what the ChipGuide OG is all about, just CASINO CHIPS. To access ChipGuide OG, just click on the link at the top of the FEATURES section, and you can return to the current ChipGuide by clicking a 2nd time. Happy Holidays.