Im sure the avarage pax will know all them airport codes
Think most people would just settle with the idea that PAX actually know the airport or country that they are flying to as a start......
Had a discussion (!!!) with an Essex couple in the 1980's when they swore they hated Spain and would refuse to go there. But they had been to Ibiza for 2 years running, Majorca in the winter and to Torremolinos for 3 years but not Spain.
Sometimes better to agree with someone that burst the sheer innocence that you see and give yourself a headache.