I'm not sure what you mean by "frequent flyer program codes." There is no official standard set of abbreviations for the names of frequent flyer programs, such as there are for airlines, commercial airports, countries in Internet domain names or Olympic games, etc., etc. Are these abbreviations people have used in FT? In that case, they're whatever the poster felt like using. AAA might, for example, be American Airlines AAdvantage, or it might not. The context might give a clue to the others. Or did you find them somewhere else? In that case, where?