Evocati (from lat. evocatio, "summoning", name of reactivated veterans in the Roman Empire), also known as Avocados or ETF is a term for a group of players who are voluntarily playtesting Star Citizen's content for future updates of the game before they are released to the Public Test Universe. The group has since grown slightly over time, and waves of inactive players were also removed at some point. They are appointed and invited by CIG, based on their contributions in the Issue Council and activity in the PTU.
The Evocati Test Flight volunteer test program started in April 2016, initially of about 800 players. Evocati are volunteers under a non-disclosure agreement. According to CIG their task is "playtesting builds to make sure they are stable before the build goes out to a wider audience."  ETF players often participate in very specific and time-limited playtests of certain features, as a way for CIG to quickly receive player feedback. ETF players were said to have also tested the Theatres of War game-mode several times in May 2020, which as of April 2022 has not been seen again.