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{{use dmy dates|date=May 2021}}
[[File:Morsetaste.jpg|thumb|right|This Morse key was originally used by [[Gotthard railway#The Gotthard railway telegraph network|Gotthard railway]], later by a [[shortwave radio]] amateur.<ref>{{cite AV media |title=Gotthard morse key used by shortwave radio amateur |medium=photo
[[File:International Morse Code.svg|thumb|upright=1.2|Chart of the Morse code 26 letters and 10 numerals<ref name=ITU-R-M-1677/>]]
{{anchor|MorseKey}}
'''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
'''International Morse code''' encodes the 26 [[ISO basic Latin alphabet|basic Latin letters]] '''{{sc|A}}''' to '''{{sc|Z}}''', one [[
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>
}}
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The American artist [[Samuel F. B. Morse|Samuel Morse]], the American [[physicist]] [[Joseph Henry]], and mechanical engineer [[Alfred Vail]] developed an [[electrical telegraph]] system. The simple "on or off" nature of its signals made it desirable to find a method of transmitting natural language using only electrical pulses and the silence between them. Around 1837, Morse therefore developed such a method, an early forerunner to the modern International Morse code.<ref name=Burns-2004/>{{rp|page=79}}
The Morse system for [[telegraphy]]
In his earliest design for a code, Morse had planned to transmit only numerals, and to use a codebook to look up each word according to the number which had been sent. However, the code was soon expanded by [[Alfred Vail]] in 1840 to include letters and special characters, so it could be used more generally. Vail estimated the [[letter frequency]] of English by counting the [[movable type]] he found in the [[Type case|type cases]] of a local newspaper in [[Morristown, New Jersey]].<ref name=Burns-2004/>{{rp|page=84}} The shorter marks were called "dots" and the longer ones "dashes", and the letters most commonly used were assigned the shortest sequences of dots and dashes. This code, first used in 1844, was what later became known as ''Morse landline code'', ''[[American Morse code]]'', or ''Railroad Morse'', until the end of railroad telegraphy in the U.S. in the 1970s.{{citation needed|date=May 2021}}
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Gerke changed many of the codepoints, in the process doing away with the different length dashes and different inter-element spaces of [[American Morse code|American Morse]], leaving only two coding elements, the dot and the dash. Codes for [[German language|German]] [[Umlaut (linguistics)|umlaut]]ed vowels and '''{{sc|CH}}''' were introduced. Gerke's code was adopted in Germany and Austria in 1851.<ref name=Deutsch-Österreich-Telegr-1851/>
This finally led to the International Morse code in 1865. The International Morse code adopted most of Gerke's codepoints. The codes for '''{{sc|O}}''' and '''{{sc|P}}''' were taken from a code system developed by Steinheil. A new codepoint was added for '''{{sc|J}}''' since Gerke did not distinguish between '''{{sc|I}}''' and '''{{sc|J}}'''. Changes were also made to '''{{sc|X}}''', '''{{sc|Y}}''', and '''{{sc|Z}}'''. The codes for the digits '''{{small|0}}'''–'''{{small|9}}''' in International Morse were completely revised from both Morse's original and Gerke's revised systems. This left only four codepoints identical to the original Morse code, namely '''{{sc|E}}''', '''{{sc|H}}''', '''{{sc|K}}''' and '''{{sc|N}}''', and the latter two had their ''dahs'' extended to full length. The original American code being compared dates to 1838; the later American code shown in the table was developed in 1844.<ref name=Smithsonian-Report-1879/>
===Radiotelegraphy and aviation===
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Radiotelegraphy using Morse code was vital during [[World War II]], especially in carrying messages between the [[warship]]s and the [[naval base]]s of the belligerents. Long-range ship-to-ship communication was by radio telegraphy, using [[encrypted]] messages because the voice radio systems on ships then were quite limited in both their range and their security. Radiotelegraphy was also extensively used by [[warplane]]s, especially by long-range [[scout plane|patrol planes]] that were sent out by navies to scout for enemy warships, cargo ships, and troop ships.
Morse code was used as an international standard for maritime distress until 1999 when it was replaced by the [[Global Maritime Distress and Safety System]]. When the [[French Navy]] ceased using Morse code on
===Demise of commercial telegraphy===
In the United States the final commercial Morse code transmission was on
{{as of|2015}}, the [[United States Air Force]] still trains ten people a year in Morse.<ref name=Swling-2015-12-10/>
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===Applications for the general public===
[[File:SOS.svg|thumb|left|250px|Representation of Morse code '''{{overline|SOS}}''']]
An important application is signalling for help through [[SOS]], "{{morse|dot|dot|dot|dash|dash|dash|dot|dot|dot}}". This can be sent many ways: keying a radio on and off, flashing a mirror, toggling a flashlight, and similar methods. The [[SOS]] signal is not sent as three separate characters; rather, it is a [[prosigns for Morse code|prosign]] {{sc|'''{{overline|SOS}}'''}}, and is keyed without gaps between characters.<ref name=QSL-Prosigns/> The specific meaning of the {{sc|'''{{overline|SOS}}'''}} prosign is equivalent to "This is the start of a distress message" (all other transmissions to go silent for the duration of the message).
===Morse code as an assistive technology===
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# short mark, dot or ''dit'' ({{morse|dot}}): "dit duration" is one time unit long
# long mark, dash or ''dah'' ({{morse|dash}}): three time units long
# inter-element gap between the ''dits''
# short gap (between letters): one dah duration silence, three time units long
# medium gap (between words): a long silence, duration the same as two (silent) dahs sent with a normal one dit gap, seven time units
===Transmission===
Morse code can be transmitted in a number of ways: Originally as electrical pulses along a [[telegraph]] wire, but later extended to an audio tone, a radio signal with short and long tones, or high and low tones, or as a mechanical, audible, or visual signal (e.g. a flashing light) using devices like an [[Aldis lamp]] or a [[heliograph]], a common flashlight, or even a car horn. Some mine rescues have used pulling on a rope - a short pull for a dot and a long pull for a ''dah''. Ground forces send messages to aircraft with panel signalling, where a horizontal panel is a dah and a vertical panel a dit.<ref>{{cite AV media |title=NATO phonetic alphabet, codes & signals |medium=poster |date=11 January 2018 |series=Communications Services, Public Diplomacy Division |publisher=[[NATO Headquarters]] |place=Brussels, Belgium |url=https://www.nato.int/nato_static_fl2014/assets/pdf/pdf_2018_01/20180111_nato-alphabet-sign-signal.pdf
Morse messages are generally transmitted by a hand-operated device such as a [[telegraph key]], so there are variations introduced by the skill of the sender and receiver — more experienced operators can send and receive at faster speeds. In addition, individual operators differ slightly, for example, using slightly longer or shorter ''dahs'' or gaps, perhaps only for particular characters. This is called their "fist", and experienced operators can recognize specific individuals by it alone. A good operator who sends clearly and is easy to copy is said to have a "good fist". A "poor fist" is a characteristic of sloppy or hard to copy Morse code.
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Morse code is often spoken or written with ''dah'' for dashes, ''dit'' for dots located at the end of a character, and ''di'' for dots located at the beginning or internally within the character. Thus, the following Morse code sequence:
:{| style="text-align:center;"
|-▼
| '''{{sc|M}}''' || '''{{sc|O}}''' || '''{{sc|R}}''' || '''{{sc|S}}''' || '''{{sc|E}}'''▼
| {{spaces|5}} || '''{{sc|C}}''' || '''{{sc|O}}''' || '''{{sc|D }}'''|| '''{{sc|E}}'''▼
|-
| {{morse|dash|dash}} || {{morse|dash|dash|dash}} || {{morse|dot|dash|dot}} || {{morse|dot|dot|dot}} || {{morse|dot}}
| || {{morse|dash|dot|dash|dot}} || {{morse|dash|dash|dash}} || {{morse|dash|dot|dot}} || {{morse|dot}}
▲|-
▲| '''{{sc|M}}''' || '''{{sc|O}}''' || '''{{sc|R}}''' || '''{{sc|S}}''' || '''{{sc|E}}'''
▲| {{spaces|5}} || '''{{sc|C}}''' || '''{{sc|O}}''' || '''{{sc|D }}'''|| '''{{sc|E}}'''
|}
is spoken (or sung):
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| ''{{nobr|dah dah}}'' || ''{{nobr|dah dah dah}}'' || ''{{nobr|di dah dit}}'' || ''{{nobr|di di dit}}'' || ''{{nobr|dit}}''
| {{spaces|3}} || ''{{nobr|dah di dah dit}}'' || ''{{nobr|dah dah dah}}'' || ''{{nobr|dah di dit}}'' || ''{{nobr|dit}}''
|-
| {{morse|dash|dash}} || {{morse|dash|dash|dash}} || {{morse|dot|dash|dot}} || {{morse|dot|dot|dot}} || {{morse|dot}}
| || {{morse|dash|dot|dash|dot}} || {{morse|dash|dash|dash}} || {{morse|dash|dot|dot}} || {{morse|dot}}
|-
| '''{{sc|M}}''' || '''{{sc|O}}''' || '''{{sc|R}}''' || '''{{sc|S}}''' || '''{{sc|E}}'''
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| Numbers || [[9 (number)|9]] || {{audio|9 number morse code.ogg|{{morse|dash|dash|dash|dash|dot}}}}
|- valign="top"
| Punctuation || [[Full stop|Period]]
|- valign="top"
| Punctuation || [[Comma (punctuation)|Comma]]
|- valign="top"
| Punctuation || [[Question mark|Question mark]]
|- valign="top"
| Punctuation || [[Apostrophe (punctuation)|Apostrophe]]
|- valign="top"
| Nonstandard <br/> punctuation{{efn|name=not-in-either-ITU-R}} || [[Exclamation mark
|- valign="top"
| Punctuation || [[Slash (punctuation)| Slash ]] or [[Fraction (mathematics)|Fraction bar]]
|- valign="top"
| Punctuation || [[Parenthesis| Open parenthesis]] [''' (
|- valign="top"
| Punctuation || [[Parenthesis| Close parenthesis]]
|- valign="top"
| Nonstandard<br/>punctuation{{efn|name=not-in-either-ITU-R}} || [[Ampersand]]
|- valign="top"
| Punctuation || [[Colon (punctuation)| Colon]]
|- valign="top"
| Nonstandard<br />punctuation{{efn|name=not-in-either-ITU-R|<br/>The character or symbol encoding is not in either [[ITU-R]] M.1172<ref name=ITU-R-M-1172/> or [[ITU-R]] M.1677-1 .<ref name=ITU-R-M-1677/>}} || [[Semicolon]]
|- valign="top"
| Punctuation || [[Equal sign| Double dash]]
|- valign="top"
| Punctuation || [[Plus and minus signs| Plus sign]]
|- valign="top"
| Punctuation || [[Hyphen]] or [[Plus and minus signs| Minus sign]]
|- valign="top"
| Nonstandard<br/>punctuation{{efn|name=not-in-either-ITU-R}} || [[Underscore| Underscore]]
|- valign="top"
| Punctuation || [[Quotation mark]]
|- valign="top"
| Nonstandard <br/> punctuation{{efn|name=not-in-either-ITU-R}} || [[Dollar sign]]
|- valign="top"
| Punctuation || [[Commercial at|At sign]]
|- valign="top"
| [[Prosigns for Morse code|Prosigns]] ||
|- valign="top"
| [[Prosigns for Morse code|Prosigns]] ||
|- valign="top"
| [[Prosigns for Morse code|Prosigns]] ||
|- valign="top"
| [[Prosigns for Morse code|Prosigns]] ||
|- valign="top"
| [[Prosigns for Morse code|Prosigns]] ||
|- valign="top"
| [[Prosigns for Morse code|Prosigns]] ||
|- valign="top"
| [[Prosigns for Morse code|Prosigns]] ||
name=E_S_for_&_note|
The well-established standard abbreviation for ''and'' is {{nobr|'''{{sc|E S}}''',}} adapted from the code for [[ampersand]] in [[American Morse Code|Railroad Morse]]. The code for {{nobr|'''{{sc|E S}}'''}} {{nobr|({{morse|dot}}{{morse|dot|dot|dot}} ) }} is actually slightly shorter in duration than the wait prosign {{nobr|({{morse|dot|dash|dot|dot|dot}} ),}} so there is no motivative to replace it.
}} || {{audio|Morse Prosign - Wait.oga|{{morse|dot|dash|dot|dot|dot}}}}
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br/>extensions || [[Ĵ|Ĵ, ĵ]] || {{audio|Ĵ Morse Code.oga|{{morse|dot|dash|dash|dash|dot}}}}
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br/>extensions || [[Ś|Ś, ś]] || {{audio|Ś Morse Code.oga|{{morse|dot|dot|dot|dash|dot|dot|dot}}}}
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|- valign="top"
| non-Latin{{efn|name=not-in-either-ITU-R}}<br
|}
=== Cut numbers ===
Most numbers have an unofficial short-form, given in the table below. They are only used when both the sender and the receiver understand that numbers, and not letters, are intended;{{citation needed|date=October 2023}} for example, one often sees the most common [[R-S-T system|R-S-T signal report]] rendered as '''{{small|5}}{{sc|NN}}'''[[#double_dagger_anchor|{{sup|[‡]}}]] instead of '''{{small|599}}'''.{{citation needed|date=October 2023}}
:{| class="wikitable"
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! 4
| {{grey|{{n/a|N/A}}[[#dagger_anchor|{{sup|[†]}}]]}}
|style="text-align:center;"| '''{{small|4}}'''[[#dagger_anchor|{{sup|[†]}}]]
| {{morse|dot|dot|dot|dot|dash}}[[#dagger_anchor|{{sup|[†]}}]]
|-
! 5
| {{morse|dot}}{{sup|[[#double_dagger_anchor|{{sup|[‡]}}]]}}
|style="text-align:center;"| {{grey|'''{{sc|e}}''' ''or''}} '''{{small|5}}'''[[#double_dagger_anchor|{{sup|[‡]}}]]
| {{morse|dot|dot|dot|dot|dot}}[[#double_dagger_anchor|{{sup|[‡]}}]]
|-
! 6
| {{grey|{{n/a|N/A}}[[#dagger_anchor|{{sup|[†]}}]]}}
|style="text-align:center;"| '''{{small|6}}'''[[#dagger_anchor|{{sup|[†]}}]]
| {{morse|dash|dot|dot|dot|dot}}[[#dagger_anchor|{{sup|[†]}}]]
|-
Line 563 ⟶ 566:
|style="text-align:center;"| {{anchor|asterisk_anchor}}[*] || Codes that are ''not'' cut numbers, or are not numbers, are {{grey|'''shaded grey'''}} in the table.
|- style="vertical-align:top;"
|style="text-align:center;"| {{anchor|dagger_anchor}}[†] || There are no distinct cut-number codes for '''{{small|4}}''' or '''{{small|6}}''', since cut numbers are made by reducing multiple ''dahs'' in the standard Morse number codes to only one ''dah'', but keeping all the ''dits'' as-is; digits '''{{small|4}}''' and '''{{small|6}}''' already
|- style="vertical-align:top;"
|style="text-align:center;"| {{anchor|double_dagger_anchor}}[‡] || Some operators just send the standard code for '''{{small|5}}''', even when using other cut numbers, since five ''dits'' are still fairly short (same duration as {{nobr|cut
|}
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=== Symbol representations ===
The symbols [''' ! '''], [''' $ '''], and [''' & '''] are not defined inside the official [[ITU-R]] ''International Morse Code Recommendation'',<ref name=ITU-R-M-1677/> but informal conventions for them exist. (The [''' @ '''] symbol was formally added in 2004. The [''' % '''] and [''' ‰ '''] symbols both have recommended long encodings<!-- TODO fixme terminology -->.<ref name=ITU-R-M-1677/>)
; Exclamation mark : There is no standard representation for the [[exclamation mark]] [''' ! '''], although the {{sc| {{overline|KW}} }} [[Digraph (orthography)|digraph]] ({{morse|dash|dot|dash|dot|dash|dash}}) was proposed in the 1980s by the [[Heathkit]] Company.{{efn|[[Heathkit]] was a popular, long-standing vendor of kits for amateur radio equipment.}} While Morse code translation software prefers the Heathkit version, on-air use is not yet universal, as some amateur radio operators in North America and the Caribbean continue to use the older {{sc| {{overline|MN}} }} digraph ({{morse|dash|dash|dash|dot}}){{efn|name=exclamation_note| {{sc| {{overline|MN}} }} or {{sc| {{overline|OE}} }}, {{morse|dash|dash|dash|dot}}, which some telegraphers unofficially use for an exclamation mark [''' ! '''], is shared with unofficial letters
; Currency symbols : The ITU has never formally codified any [[currency symbol]]s into Morse code: The unambiguous [[ISO 4217]] currency codes are preferred for transmission (e.g. [[CNY]], [[EUR]], [[GBP]], [[JPY]], [[South Korean won|KRW]], [[USD]], etc.). However, the {{nobr|symbol [''' $ ''']}} was represented in the [[Phillips Code]]{{efn|The [[Phillips Code]] was a huge collection of abbreviations used on land line telegraphy.}} as two characters "'''{{sc|SX}}'''"; eventually operators dropped the intervening space and merged the two letter code or abbreviation into the single unofficial punctuation encoding {{sc| {{overline|SX}} }} ({{morse|dot|dot|dot|dash|dot|dot|dash}}).
; Ampersand [''' & '''] : The suggested unofficial encoding of the [[ampersand]] [''' & '''] sign listed above,{{efn|name=E_S_for_&_note}} often shown as {{sc| {{overline|AS}} }}, is also the official Morse [[Prosigns for Morse code|prosign]] for ''wait''. In addition, the [[American Morse code|American Morse encoding]] for an ampersand ({{morse|dot|aspace|dot|dot|dot}}) was similar to '''{{sc|ES}}''' ({{morse|dot}}{{morse|dot|dot|dot}}) and [[Amateur radio operators|hams]] have nearly universally carried over this use as an abbreviation for "and" (e.g.
; Keyboard "at" sign [''' @ '''] : On 24 May 2004 – the 160th anniversary of the first public Morse telegraph transmission – the Radiocommunication Bureau of the International Telecommunication Union ([[ITU-R]]) formally added the [''' @ '''] ("[[commercial at]]" or "commat") character to the official Morse character set, using the sequence denoted by the {{sc| {{overline|AC}} }} digraph: {{morse|dot|dash|dash|dot|dash|dot}} .<ref name=ITU-R-M-1677/><ref name=ARRL-News-2003-12-10/>▼
▲; Ampersand [&] : The suggested unofficial encoding of the [[ampersand]] ['''&'''] sign listed above,{{efn|name=E_S_for_&_note}} often shown as {{sc| {{overline|AS}} }}, is also the official Morse [[Prosigns for Morse code|prosign]] for ''wait''. In addition, the [[American Morse code|American Morse encoding]] for an ampersand ({{morse|dot|aspace|dot|dot|dot}}) was similar to '''{{sc|ES}}''' ({{morse|dot}}{{morse|dot|dot|dot}}) and [[Amateur radio operators|hams]] have nearly universally carried over this use as an abbreviation for "and" (e.g. '''{{sc|WX HR COLD ES RAINY}}''' ''the weather here is cold and rainy'').
: This sequence was reported to have been chosen to represent "A[t] C[ommercial]", or a {{nobr|letter
▲; Keyboard "at" sign [@] : On 24 May 2004 – the 160th anniversary of the first public Morse telegraph transmission – the Radiocommunication Bureau of the International Telecommunication Union ([[ITU-R]]) formally added the ['''@'''] ("[[commercial at]]" or "commat") character to the official Morse character set, using the sequence denoted by the {{sc| {{overline|AC}} }} digraph: {{morse|dot|dash|dash|dot|dash|dot}} .<ref name=ITU-R-M-1677/><ref name=ARRL-News-2003-12-10/>
; Percent [''' % '''] and permille [''' ‰ '''] signs
▲: This sequence was reported to have been chosen to represent "A[t] C[ommercial]", or a letter "a" inside a swirl represented by a letter "C". The new character facilitates sending [[email|e‑mail]] addresses by Morse code, and is notable since it is the first official addition to the Morse set of characters since [[World War I]].<ref name=ARRL-News-2003-12-10/>
: [[Percent sign|Percent]] and [[Per mille sign|permille]] signs should be encoded with zeroes separated by a slash, joined to the preceding number by a dash; so e.g. “4%” would be sent as “4-0/0”, and “5‰” as “5-0/00”, and “6.7%” as “6.7-0/0”.<ref name=ITU-R-M-1677/>
===Diacritics and non-Latin extensions <span class="anchor" id="Non-Latin extensions"></span>===
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|date=23 January 1999
|magazine=[[The Economist]]
|url=https://www.economist.com/
|url-status=live
|archive-url=https://web.archive.org/web/20170330221624/https://www.economist.com/node/183572
|archive-date=2017-03-30
| |||