NATO phonetic alphabet by those who exchange voice messages by radio or telephone, regardless of language differences or the quality of the communication channel. The 26 code words in the NATO phonetic alphabet are assigned to the 26 letters of the English alphabet in alphabetical order as follows: , Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, , Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu. Strict adherence to the prescribed spelling words is required in order to avoid the problems of confusion that the spelling alphabet is designed to overcome. As noted in a
NATO phonetic alphabet code words for the letters of the alphabet and for the digits was made after hundreds of thousands of comprehension tests involving 31 nationalities. The qualifying feature was the likelihood of a code word being understood in the context of others. For example, "football" has a higher chance of being understood than "foxtrot" in isolation, but "foxtrot" is superior in extended communication. The pronunciation of the code words varies according to the language habits of the speaker. To eliminate wide variations in pronunciation, recordings and posters illustrating the pronunciation desired by the ICAO are available. However, there are still differences