I am in HK airport waiting for my flight and I noticed that there is one CX flight with three flight numbers attached:CX 721, MH 9721, BA 4561. The flight is from Hong Kong to Kuala Lumpur and then to Penang. This is the first time I have seen so many different numbers on one single flight.
The question is: what is the highest number of flight numbers attached to one flight you have seen? I know two is very common, but three is the first for me!