Lower berth Quota once completely booked, it will show availability as NOT AVAILABLE. If someone cancelled hie/her LB quota berth after showing NOT AVAILABLE, it remains as hidden quota in system and allotted while charting for the eligible person as per their priority in booking (first come, first serve basis). If no one in booking is eligible for LB quota while charting, than that hidden vacant berth will go to GN WL as per priority.