Let’s be honest, some of these rules exist because someone ruined it for everyone. You cannot bring backpacks, coolers, duffel bags, or any opaque bag larger than a clutch. Also, no camera bags, computer bags, or fanny packs that aren’t clear. Basically, if your bag has a zipper and a sense of privacy, it’s staying in the parking lot.
But the surprise villain is the clear tote bag that is the wrong size. I once saw a woman try to bring a clear bag that was 13 inches long. The guard looked at it like it was a loaded weapon. “Ma’am, that’s one inch over regulation. One inch. You’ve broken the covenant.” She had to walk it back, dignity in tatters.