Stephen Fry says that there are almost 19500 airports in the world, and that "every single one of them" uses the three letter identification code (known as the IATA airport code) that are typically found on baggage tags etc. This is incorrect: not all airports use this code, because simply there aren't enough unique combinations; 26 times 26 times 26 is 17576, and as stated above, the number of airports in the world exceeds that. The code that designates every single airport around the world is a four-character alphanumeric code called the ICAO airport code (which has a total of 1679616 possible combinations).