An aviator call sign or callsign is a nickname given to a military pilot, flight officer, and even some enlisted aviators. This call sign is a substitute for the aviator's given name, and is used on flight suit and flight jacket name tags, painted/displayed beneath the officer's or enlisted aircrewman's name on aircraft fuselages or canopy rails, and in radio conversations. They are most commonly used in tactical jet aircraft communities (i.e., fighter and attack) than in other aircraft communities (i.e., airlift, mobility, maritime patrol), but their use is not totally exclusive to the former. Many NASA Astronauts with military aviator backgrounds are referred to during spaceflights by their call signs rather than their first names.