The system used by pilots and air traffic controllers is officially known as the International Radiotelephony Spelling Alphabet, though it is most commonly called the NATO Phonetic Alphabet or the ICAO Alphabet. Developed by the International Civil Aviation Organization (ICAO) in the 1950s, its primary purpose is to eliminate ambiguity in voice communications. Because many letters sound similar over poor radio connections (like "M" and "N" or "B" and "D"), the alphabet assigns a unique word to each letter: Alfa, Bravo, Charlie, Delta, Echo, Foxtrot... and so on. In 2026, this remains the global standard to ensure that a pilot from Japan can clearly communicate a tail number or waypoint to a controller in France without linguistic confusion. Interestingly, it also includes specific pronunciations for numbers, such as "tree" for 3, "fife" for 5, and "niner" for 9, to further prevent errors.