The IDLE REVERSE is another detent in the A320 throttle quadrant. It’s basically switching the engine to reverse, but instead of applying full reverse thrust, it’s applying the same thrust as an idle thrust. Just in reverse direction. It’s usually used to either save fuel on landing and to minimise noise on longer runways that you don’t need full reverse to stop.
The TCA quadrant doesn’t have that detent being designed, so I usually set this if I hold it slightly under the idle latch. If I move it back further it will apply the full reverse.
