The retail cashier's favorite joke...NOT!
Worse yet, it's not even our jobs to make sure shit is tagged properly, it's the floor associates. Get them on the radio, it takes 10 minutes to get a SKU or UPC! Tell them that their shit doesn't have the right tag, no tag, or is not in the system and they look at you like "So?"
My other favorite phrase that customer throw at me is "The sign says..."! Example - they bring two items up and say "The sign says these are buy one get one free." No, that's what you want it to say, what it really says is "Buy one get one 50% off."