HS – Have sold – provisionally held flight


HK – Holds confirmed – confirmed flight


NN – Need request – not yet confirmed by the airline


PN – Pending need – waiting for confirmation from the airline


UC/UN – Unable to confirm 


HX – Cancelled by the airline


KK – Airline confirms a booking from NN or PN status


TK – Airline time/flight number change


AK – Passive flight