During WWI , Seneca edition, with spelling alphabet for telephone and radio use In
World War I battle lines were relatively static and forces were commonly linked by wired telephones. Signals could be weak on long wire runs and
field telephone systems often used a single wire with
earth return, which made them subject to inadvertent and deliberate interference. Spelling alphabets were introduced for wire telephony as well as on the newer radio voice equipment.
Between WWI and WWII Commercial and international telephone and radiotelephone spelling alphabets.
During WWII The later
NATO phonetic alphabet evolved from the
procedures of several different Allied nations during World War II, including: • The United States Navy (multiple versions in 1913, 1927, 1938, and WWII) • The United States Army (multiple versions in 1916, 1939, 1944, and 1961) • The United States Army Air Force • Joint Army/Navy Phonetic Alphabet (1941–1956) • The British Royal Air Force phonetic alphabet (1921 onwards)
Post-WWII For the 1938 and 1947 alphabets, each transmission of figures is preceded and followed by the words "as a number" spoken twice. The ITU adopted the
International Maritime Organization's phonetic spelling alphabet in 1959, and in 1969 specified that it be "for application in the maritime mobile service only". During the late 1940s and early 1950s, there were two international aviation radio spelling alphabets, the "Able Baker" was used by most Western countries, while the "Ana Brazil" alphabet was used by South American and Caribbean regions. Pronunciation was not defined prior to 1959. From 1959 to present, the underlined syllable of each code word for the letters should be stressed, and from 1969 to present, each syllable of the code words for the digits should be equally stressed, with the exceptions of the unstressed second syllables of fower, seven, niner, hundred.
ICAO Radiotelephone Spelling Alphabet After WWII, the major work in producing a better spelling alphabet was conducted by the ICAO, which was subsequently adopted in modified form by the ITU and IMO. Its development is related to these various international conventions on radio, including: • Universal Electrical Communications Union, Washington, D.C., December 1920 • General Radiocommunication and Additional Regulations (Madrid, 1932) • Instructions for the International Telephone Service, 1932 (ITU-T E.141; withdrawn in 1993) • The ARRL and 1928 Western Union alphabets likely originated earlier. • General Radiocommunication Regulations and Additional Radiocommunication Regulations (Cairo, 1938) • Radio Regulations and Additional Radio Regulations (Atlantic City, 1947), where "it was decided that the International Civil Aviation Organization and other international aeronautical organizations would assume the responsibility for procedures and regulations related to aeronautical communication. However, ITU would continue to maintain general procedures regarding distress signals." • 1959 Administrative Radio Conference (Geneva, 1959) • Final Acts of WARC-79 (Geneva, 1979). Here the alphabet was formally named "Phonetic Alphabet and Figure Code". • International Code of Signals for Visual, Sound, and Radio Communications, United States Edition, 1969 (Revised 2003) • NATO phonetic alphabet history •
International Telecommunication Union, Radio The
ICAO Radiotelephony Alphabet is defined by the
International Civil Aviation Organization for international aircraft communications.
Law enforcement Defined by the
Association of Public-Safety Communications Officials-International. The APCO first suggested that its Procedure and Signals Committee work out a system for a "standard set of words representing the alphabet should be used by all stations" in its April 1940 newsletter. Note: The old APCO alphabet has wide usage among Public Safety agencies nationwide, even though APCO itself deprecated the alphabet in 1974, replacing it with the ICAO spelling alphabet. See https://www.apcointl.org and
APCO radiotelephony spelling alphabet.
Amateur radio The FCC regulations for Amateur radio state that "Use of a phonetic alphabet as an aid for correct station identification is encouraged" (47 C.F.R. § 97.119(b)(2)), but does not state which set of words should be used. Officially the same as used by ICAO, but there are significant variations commonly used by stations participating in HF contests and DX (especially in international HF communications). The official ARRL alphabet changed over the years, sometimes to reflect the current norms, and sometimes by the force of law. In rules made effective beginning April 1, 1946, the FCC forbade using the names of cities, states, or countries in spelling alphabets. ==Additions in other languages==