This one is a mystery. It' listed in the Nevada Promo Token book (1068.0) so it's 15 or more years old. White plastic with a symbol that seems to say "no Roman celebrating". Reverse has a serial number so it's possible this is an early slot club member card. My guess though is that it was given out to jackpot winners to allow them to compete for some prize. There's another variety with different style reverse. These are the only two Caesars Tahoe promo items in the book.