The NATO phonetic alphabet, more accurately known as the International Radiotelephony Spelling Alphabet and also called the ICAO phonetic or ICAO spelling alphabet, as well as the ITU phonetic alphabet, is the most widely used spelling alphabet. Although often called "phonetic alphabets", spelling alphabets do not have any association with phonetic transcription systems, such as the International Phonetic Alphabet. Instead, the International Civil Aviation Organization (ICAO) alphabet assigned code words acrophonically to the letters of the English alphabet so that critical combinations of letters and numbers can be pronounced and understood by those who transmit and receive voice messages by radio or telephone regardless of their native language or the presence of transmission static.
The 26 code words in the NATO phonetic 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. Some of the 26 words have altered pronunciations: Charlie can be spoken as either "char-lee" or "shar-lee" and Uniform as either "you-nee-form" or "oo-nee-form". Oscar is pronounced "oss-cah" and Victor as "vik-tah" without the 'r'. Papa is pronounced "Pa-PAH" with the accent on the second syllable instead of the first. The code word Quebec is pronounced as French "keh-beck". The ICAO and FAA use the standard number words of English (zero, one, two, three, four, five, six, seven, eight, nine) with four altered pronunciations (tree, fower, fife, niner), whereas the ITU and IMO use ten code words for numbers (nadazero, unaone, bissotwo, terrathree, kartefour, pantafive, soxisix, setteseven, octoeight, novenine).