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 member of the working committee of the Combined Communications Board), enlisted the help of Harvard University's Psycho-Acoustic Laboratory, asking them to determine the most successful word for each letter when using "military interphones in the intense noise encountered in modern warfare.". He included lists from the USA, Royal Air Force, Royal Navy, British Army, AT&T, Western Union, RCA Communications, and that of the International Telecommunications Convention. According to a report on the subject, The results showed that many of the words in the military lists had a low level of intelligibility, but that most of the deficiencies could be remedied