Sometimes in a restaurant, when you order regular coffee the waitress will bring decaf. In most restaurants, after 8 p.m. or so, all the coffee is decaf because no one wants to clean two different coffeepots. The server will bring out a tray with 12 coffees on it and give some to the customers who ordered regular, others to the ones who ordered decaf. But they're all decaf.
Source: Reader’s Digest, 10/3/12