Sometimes it is difficult to get a message across the circuit correctly and you need to resort to spelling the words of the message. This is where the ‘International Radiotelephony Spelling Alphabet’ comes in. This alphabet was originally used by the International Civil Aeronautical Organization (ICAO) and called the ICAO Phonetic Alphabet. It used standard words and pronunciations of those words to allow airplane pilots and air traffic control operators from around the world to understand each other. The alphabet has since been adopted by the North Atlantic Treaty Organization (NATO) where it is called the NATO Phonetic Alphabet, by the International Telecommunications Union (ITU), and by the American Radio Relay League (ARRL) as well as several other international organizations.
The alphabet covers the twenty-six letters of the English alphabet and the numbers from one to zero. Most of the letters and numbers are pronounced as in common English usage, however, some are distinctly different. It is important to pronounce all of the letters and numbers in the specified manner in order to insure maximum understanding. The syllables in boldface type are emphasized in the pronunciation of the code word.