NATO phonetic alphabet
The International Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet or the ICAO phonetic alphabet, is the most widely used radiotelephone spelling alphabet. The ITU phonetic alphabet and figure code is a variant.
To create the alphabet, the International Civil Aviation Organization (ICAO) assigned codewords acrophonically to the letters of the English alphabet, so that letters and numbers would have distinct names that would be most easily understood by those who exchange voice messages by radio or telephone, regardless of language differences or the quality of the communication channel. Such spelling alphabets are often called "phonetic alphabets", but they are unrelated to phonetic transcription systems such as the International Phonetic Alphabet.
The 26 code words in the spelling alphabet are assigned to the 26 letters of the English alphabet in alphabetical order as follows: Alfa, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.Strict adherence to the prescribed spelling words—including the apparently misspelled "Alfa" and "Juliett"—is required in order to avoid the problems of confusion that the spelling alphabet is designed to overcome. A 1955 NATO memo stated that:
It is known that [the ICAO spelling alphabet] has been prepared only after the most exhaustive tests on a scientific basis by several nations. One of the firmest conclusions reached was that it was not practical to make an isolated change to clear confusion between one pair of letters. To change one word involves reconsideration of the whole alphabet to ensure that the change proposed to clear one confusion does not itself introduce others.