No, you're thinking of a different thing. In SF some restaurant will have an "SF employee mandate" line, a 2% surcharge or so, to account for a local law. That'

No, you're thinking of a different thing. In SF some restaurant will have an "SF employee mandate" line, a 2% surcharge or so, to account for a local law. That's a protest against the law: it's the same principle behind listing tax-excluded prices, basically making sure people see how much the local taxes cost them. A smaller set of restaurant does something different. They list some prices, and then in the fine print at the bottom they say "a 6% surcharge will be added to provide a living wage in SF", or something. This is not to comply with any local tax or law, it's just paying your employees more on your own accord, but then excluding an arbitrary percentage of that from your listed prices because... I have no idea why. But all places I've seen that do this have been very left-of-center.