'''Morse code''' is a [[telecommunications]] method which [[Character encoding|encodes]] [[Written language|text]] characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''.<ref name=Beechey-1876/><ref name=Camm-1941/> Morse code is named after [[Samuel Morse]], one of the early developers of the system adopted for [[electrical telegraph]]y.
'''International Morse code''' encodes the 26 [[ISO basic Latin alphabet|basic Latin letters]] '''{{sc|A}}''' to '''{{sc|Z}}''', one [[Diacritic|accented]] Latin letter ('''{{sc|[[É]]}}'''), the [[Arabic numerals]], and a small set of punctuation and procedural signals ([[Prosigns for Morse code|prosigns]]). There is no distinction between upper and lower case letters.<ref name=ITU-R-M-1677/> Each Morse code symbol is formed by a sequence of ''dits'' and ''dahs''. The ''dit'' duration can vary for signal clarity and operator skill, but for any one message, once the [[rhythm]] is established, a [[beat (music)|half-beat]] is the basic unit of time measurement in Morse code. The duration of a ''dah'' is three times the duration of a ''dit'' (although some telegraphers deliberately exaggerate the length of a ''dah'' for clearer signalling). Each ''dit'' or ''dah'' within an encoded character is followed by a period of signal absence, called a ''space'', equal to the ''dit'' duration. The letters of a word are [[Delimiter|separated by]] a space of duration equal to three ''dits'', and words are separated by a space equal to seven ''dits''.<ref name=ITU-R-M-1677/><ref name=TR-Paris-1949>{{cite report |title=Telegraph Regulations |orig-year=1947 |year=1949 |series=ITU History |place=Geneva, CH |publisher=[[International Telecommunication Union]] |url=https://search.itu.int/history/HistoryDigitalCollectionDocLibrary/1.36.48.en.100.pdf |page=42 |quote=the space between two words is equal to seven dots;}} — Annexed to the ''International Telecommunication Convention'', Atlantic City, 1947; revised Paris, 1949.</ref>{{efn|
Until 1949, words were separated by a space equal to five ''dits''.<ref name=TR-Cairo-1938>{{cite report |title=Telegraph Regulations |orig-year=1932 |year=1938 |series=ITU History |place=Geneva, CH |publisher=[[International Telecommunication Union]] |url=https://search.itu.int/history/HistoryDigitalCollectionDocLibrary/1.35.48.en.100.pdf#search=morse%201938 |page=39 |quote=The space between two words is equal to five dots.}} — Annexed to the ''International Telecommunication Convention'', Madrid, 1932; revised Cairo, 1938.</ref>
