No, I didn't. MY first thought was "AirNZ doesn't fly to anywhere with a code of AUX. Where the heck is that anyway?" So I looked it up.

Since I live in Auckland, I know full well that its code is AKL, not AUX or AUK (which I have also seen used in error).

AirNZ being my national airline, I am also aware of the routes it flies.

My point remains the same: If you don't know the correct 3-letter code for an airport, either look it up or use the airport's name.