1 and 2
1 and 2
Deceleration point, where the aircraft expects you to begin extending the slats and flaps. So at no.1 the aircraft expects you to extend the flaps to the 1 position and so on. This is mostly found on the A350 and A380 (if I’m not mistaken ).
As mentioned these are the locations where, at the latest, flaps 1 and flaps 2 need to be selected to allow the aircraft to decelerate to final approach speed.