The compensation for flight attendants on standby (often called "reserve") is a nuanced part of airline labor contracts. Generally, flight attendants do receive a base pay or a "reserve guarantee," which is a minimum number of hours they are paid for each month regardless of whether they actually fly. However, they typically do not earn their full "flight pay" rate just for sitting in the airport or waiting at home. Flight pay usually only kicks in once the aircraft door is closed (the "block-to-block" time). While on "Airport Reserve," where they must be in uniform at the airport ready to go at a moment's notice, they may receive a small hourly stipend or "per diem," but it is significantly less than their active flying rate. This is a major point of contention in union negotiations, as many crew members argue they are working by being restricted in their movements and availability, even if they aren't currently in the air. The specifics vary wildly between legacy carriers and budget airlines.