In restaurants the tags usually go straight to the office. In a butcher shop I handled all of the seafood and we kept a little plastic filing box with the tags

In restaurants the tags usually go straight to the office. In a butcher shop I handled all of the seafood and we kept a little plastic filing box with the tags in a folder by month. I think there is some rule about keeping them 30 days or so after the stop of sale. We were always able to provide the tags easily because health inspectors check them. I told customers about the tags when they asked about the safety of eating oysters. I don’t remember ever being asked for them by a customer but once I turned away a box of either oysters or mussels from a supplier whose tag had fallen off. Personally I would respect a customer who asks to see the tags once to see if the place is compliant. It’s like when a customer corrects someone who asks if the sushi-grade fish is “fresh” or “never frozen” (being frozen at extreme temperature is what makes it legally sushi-grade and the equipped ships are often at sea for months, so “fresh” is just a buzzword). It’s encouraging when consumers know the product.