American Football Rules IFAF Approved Ruling 6-5-3:III-V

III. A scrimmage kick strikes the ground beyond the neutral zone and bounces high into the air and B1 signals for a fair catch. RULING: Invalid signal. The ball is dead when recovered.
[Cited by 2-8-3-b]
IV. B1 catches a scrimmage kick beyond the neutral zone and then signals for a fair catch.
RULING: Invalid signal. The ball is dead where the signal first was given. [Cited by 2-8-3-b]
V. Team A’s scrimmage kick is rolling beyond the neutral zone when B17 alerts his teammates to stay away from the ball by a “get away” signal. RULING: Invalid signal. The ball is dead by rule when either team recovers. [Cited by 2-8-3-b]