... and focus on making it "definitive". As I previously stated in that lengthy discussion thread about proof/facts vs. the "attribute to" lingo, you simply need documentation as evidence to support any claim. Pass that documentation onward to those who generate the chip collecting guides.

Your case in point, if the casino issued the chip in question: handed it to you to use inside their casino at any table game and the chip was generic in appearance, had insufficient markings (no casino name) on it, did not look like any other chip inside the casino, but accepted inside that very casino to use anywhere as a legitimate chip, then that casino will have the information you need to prove your provenance. Go back to that casino, show them the chip and ask about it - why was this chip used/issued on the date in question? Ask them "politely" to see if they would give you something in writing that states that indeed the chip in question was issued at said casino for whatever reason. Even if you had video showing the chip in play at said casino, that is proof. Keep a digital camera or cell phone with video capability with you the next time you go to a casino - have your own proof right then and there.

Regards,
Thomas (R-7788)