International Phonetic Alphabet Amateur radio operators are required to identify themselves over the air by their alphanumeric call signs, so its no wonder that many hams may know one another only by the sign instead of an actual name or handle. However, identifying the call signs correctly can be a challenge, especially when the letters in a sign sound similar to one another. For instance, the letter “M” sounds similar to the letter “N”, “B” may sound like “D”, and so forth. This can be particularly troublesome if the transmission is weak or encounters a lot of interference.
To avoid confusion and clarify communications, amateurs use the phonetic alphabet. It was not a unique concept, as phonetic alphabets were already in use by the British military during World War 1, but it was not worldwide standard. The first known international alphabet was established by the International Telecommunications Union (ITU) in 1926. The ITU made various changes to the alphabet during the next twenty years until a version was adopted by the International Civil Aviation Organization (ICAO) in 1956 and finalized by the ICU. The phonetic alphabet in use today is now a universally recognized standard.
Here is the internationally recognized ITU Amateur (Ham) Radio phonetic alphabet