These are just IATA (International Air Transport Association) codes. They are used in aviation to identify and differentiate airports. That’s why a Cape Town Intl Airport to Milan Malpensa Airport flight would often be abbreviated as a CPT to MXP flight. This flight route has multiple associated airports, so we think it might be helpful to learn the name and codes of them as well. They are Bergamo Orio Al Serio Airport (BGY), Milan Linate Airport (LIN), Parma Airport (PMF).