Rebound damping
The damper’s resistance while extending. More rebound tends to hold the platform down and settle body motions — useful for aero stability and for slowing the pitch change as brakes are applied — but too much keeps the damper from extending fast enough, momentarily unloading the tire and inviting oscillations. Less rebound lets the tire chase the surface at the cost of a busier platform. Balance it against bump damping and spring stiffness rather than tuning it in isolation.
Effect by corner phase
Rear rebound in particular can slow the forward pitch under braking, which tends to add braking stability.
Rebound control keeps the platform — and with it the aero balance — steadier through sustained load.
Symptom tendencies
These describe tendencies, not rules.
The car feels disconnected or oscillates after kerbs
Too much rebound at that end is a usual suspect — the tire is being held off the road as the damper recovers.
Verify on track before you commit to a change.