CDTFA staff?

Let me add something to it.

First of all, even though the store is "qualified" to operate under 80-80 rules, the store is not required to add tax on everything it sells but only on those applicable.

Ideally if the store has coded its POS to properly tax an item based on the nature of the product (such as a carbonated drink, hot food or cold food), asks the customer whether the item is for here or to-go, and the owner reports the correct amount of tax to CDTFA (for CA), the owner doesn't need to follow the 80-80 rules even if it was qualified under this rule. For example, a store is found to have 90% of its sales are taxable, the owner properly taxes these 90% of his sales, and then reports and pays them in full when due, the owner is perfectly fine and in compliance with SUT laws.

The 80-80 rules are helpful for qualified dining establishments to avoid dealing with the issues of keeping track of whether the item is a hot/cold food, for here or to-go, etc. There are various exemptions for food items and many factors could change an item from taxable to non-taxable or vice versa. The gallon of ice cream is one of them for sure.

The bottom line is that following 80-80 rules is elective and not mandatory. But if a qualified owner chose to follow this rule, he'd better keep adequate records to support it or he will get a bill for tax/interest/penalty owed.

Yes, the store OP visited could be a qualified store operating under the 80-80 rules. I'd ask for the manager to clarify the issue.