Procedure signs or prosigns are shorthand signals used in radio telegraphy procedures, for the purpose of simplifying and standardizing communications related to radio operating issues among two or more radio operators. They are distinct from general Morse code abbreviations, which consist mainly of brevity codes that convey messages to other parties with greater speed and accuracy.
There are also specialized variations used in radio nets to manage transmission and formatting of messages. In this usage, Morse prosigns play a role similar to the role played by the nonprinting control characters of teleprinter and computer character set codes such as Baudot or ASCII.
The development of prosigns began development in the 1860s for wired telegraphy. They can be distinguished from abbreviations because prosigns have exact equivalents for radio telephony (voice) procedure words.
Although as written, some of the prosigns appear to be simply two adjacent letters, most prosigns are instead digraphs that have zero spacing between the patterns that represent the "combined" letters, and are properly written with an overbar (if more than one single character) to indicate this. The difference is subtle, but the meaning is not. For example, the prosign AA (▄▄▄▄▄▄▄▄▄▄▄▄▄▄) has the same meaning as the voice procedure word UNKNOWN STATION, but the prosign AA (▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄) has the same meaning as the voice procedure word "ALL AFTER", and is used to indicate that part of the previously transmitted message needs to be re-transmitted; the only difference between the Morse code prosigns is an inter-letter space between the two "dot dash dot dash" sequences".
In the early decades of telegraphy many operating efficiency improvements were incorporated into telegraph operations, including the introduction of Morse symbols known as procedure signs or prosigns. Prosigns were not defined by the inventors of Morse code, but were gradually introduced over time, and greatly improved the speed and performance of daily high-volume message handling operations.
Improvements to the legibility of formal written telegraph messages (telegrams) by means of white space formatting were thus supported by the creation of the additional new procedure symbols. Mastery of these special Morse code prosigns is an important part of becoming a fluent and efficient telegrapher/telegraphist.
Prosigns may be represented in printed material either by a sequence of dots and dashes, or by a sequence of letters, which, if sent without the normal inter-character spacing (concatenated), correspond to the prosign symbol.
For example, when embedded in text the Morse code dot/dash sequence (▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄) represents the character "=" or "—"; when it appears alone it indicates the action of spacing down two lines on a page in order to create the white space indicating the start of a new paragraph or new section in a message heading. There is no actual written or printed character representation or symbol for a new paragraph (no symbol corresponding to "¶"), other than the two line white spaces themselves. Many Morse code prosigns do not have written or printed textual character representations in the original source information.
Of methods used to represent Morse prosign symbols there are at least three:
Some prosigns are in unofficial use for special characters in languages other than English, for example "Ä" and AA, neither of which is part of the international standard. Other prosigns are officially designated for both letters and prosigns, such as "+" and AR.. Some genuinely have only one use, such as CT or KA (▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄), the International Morse prosign that marks the start of a new transmission or new message.
The procedure signs below are compiled from the official specification for Morse Code, ITU-R M.1677, International Morse Code, while others are defined the International Radio Regulations, including ITU-R M.1170, ITU-R M.1172, ITU-R M.1677-1, and the International Code of Signals, with a few details of their usage appearing in ACP-131, which otherwise defines operating signals, not procedure signals.
|Prosign||Matching Voice Procedure Word||Code Symbol||Defined in||Explanation|
|DE||THIS IS||▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172ITU-R M.1677-1||Used to preceded the name or other identification of the calling station.|
|AA||UNKNOWN STATION||▄▄▄▄▄▄▄▄▄▄▄▄▄▄||International Code of Signals|
||ITU-R M.1172||Means the last transmission has been received, but does not indicate the message was understood or will be complied with.|
||ITU-R M.1677-1||invitation to transmit, Terminating the call signal (e.g. call sign—DE—▄▄▄▄▄▄▄▄▄▄▄▄)|
||ITU-R M.1172ITU-R M.1677-1||Used to terminate all telegrams (end of message). End of transmission. Same symbol as +
Replacement for K? See conflicting cw procedure
|CQ||CQ||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172||General call to all stations|
|CP||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172||General call to two or more specified stations|
|CS||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172||What is the name or identity signal of your station?|
||ITU-R M. 1170ITU-R M.1172
|I must pause for a few seconds. May optionally be followed by a number indicating in minutes the probable duration of the waiting time.|
|AS AR||WAIT OUT||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ACP 124||I must pause for a more than a few seconds.|
||ITU-R M.1677-1||understood. Response to AS/WAIT? Research to see if ARRL-specific.|
|WA||WORD AFTER||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172|
|WB||WORD BEFORE||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172|
|AA||ALL AFTER||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172||The portion of the message to which I have reference is all that follows……………|
|AB||ALL BEFORE||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172|
|BN||ALL BETWEEN||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172||All between ... and ...|
||ITU-R M.1677-1ACP 124||Note of interrogation or request for repetition of a transmission not understood.
When ? is placed after a signal, modifies the signal to be a question or request.
|INT||INTERROGATIVE||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ACP 124||Military equivalent of the ? prosign. When placed before a signal, modifies the signal to be a question/request. Was previously "The correctness of a short portion of a message may be questioned directly by the receiving operator using the interrogatory prosign INT, but this method should not be used to question a part of a message for which a receipt has been given.|
|N||NEGATIVE||▄▄▄▄▄▄▄▄||International Code of SignalsACP 131||Double check ITU docs. NO (▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄) in aeronautical usage.|
|ZWF||WRONG||▄▄▄▄▄▄▄▄▄▄▄▄▄▄ ▄▄▄▄▄▄▄▄▄▄▄▄ ▄▄▄▄▄▄▄▄▄▄▄▄||Your last transmission was wrong. The correct version is ...|
|EEEEEEEE AR||DISREGARD THIS TRANSMISSION—OUT||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄ ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||This transmission is in error, disregard it. (This proword shall not be used to cancel a message that has been completely transmitted and receipted.|
|QTR||REQUEST TIME CHECK||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||I am requesting an accurate time check.|
|QTR||TIME||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||The time I am transmitting is exact as at the moment I transmit [the R in QTR?]|
|BT||BREAK||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172ITU-R M.1677-1||Same symbol as =|
|BK||BREAK-IN||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172||Signal used to interrupt a transmission in progress. AX in ACP131|
||ITU-R M.1172ITU-R M.1677-1||Starting signal, to precede every transmission. Sometimes written as CT (start of work/new message).|
|CFM||I ACKNOWLEDGE||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172||Confirm?|
|WX||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||ITU-R M.1172||Weather report follows|
|ITU-R M.1172||International Code of Signals groups follow|
For the special purpose of exchanging ARRL Radiograms during National Traffic System nets, the following prosigns and signals can be used, but many of them do not have equivalents in any other definition of Morse code signals, including the ITU-R and Combined Communications Electronics Board telecommunications specifications.
|Prosign||Code Symbol||Meaning||Comments||Verbalization||As text|
|AA||▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Start new line||Space down one line; typewritten as Carriage Return, Line Feed (CR-LF). Also written RT.||"didahdidah"||Ä, Á|
|AR||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Message separator, start new message / telegram.||New Page, space down several lines. Decoder software may show "+". Alternative for "Break" in conversational Morse. Also written RN.||"didahdidahdit"||+|
|AS||▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Wait ||Respond with: SN, or characters "R" (Received) or "C" (Confirmed).||"didahdididit"||&|
|BT||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Start of new section / new paragraph.||Space down two lines; typewritten CR-LF-LF. Decoder software may show "=".||"dahdidididah"||=, — |
|CT||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Start of transmission Start of new message.||Attention commencing transmission. Also written KA.||"dahdidahdidah"|
|HH||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Error / correction||Always followed by correct text. Sometimes transcribed as "????". Sometimes written EEEEEEEE.||"didididididididit"|
|K||▄▄▄▄▄▄▄▄▄▄▄▄||Invitation for any station to transmit||Lone alphabetic character "K" at the end of a transmission.||"dahdidah"||K|
|?||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Please say again||Lone question mark "?" from the receiving station in response to a transmission.||"dididahdahdidit"||?|
|KN||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Invitation for named station to transmit||Go ahead, specific named station. Decoder software may show "(".||"dahdidahdahdit"||(|
|NJ||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Shift to Wabun code||Shift from Morse code to Wabun code Kana characters. Also written XM.||"dahdididahdahdah"|
|SK||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||End of contact / End of work||Also written VA.||"didididahdidah"|
|SN||▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Understood. Verified.||Message received and checks okay. Alternatively shift from Wabun to Morse code. "SN?" verification requested. Also written VE.||"didididahdit"||Š, Ś|
|SOS||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Start of distress signal||Only used by original message sender, and only for imminent danger to life or property. ( listen (help·info))||"didididahdahdahdididit"|
|BK||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Break in conversation||Morse abbreviation for "back-to you". In conversational Morse some use AR, KN, or "K" instead.||"dahdididitdadidah"||BK|
|CL||▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄||Closing down||Abbreviation for "closing station" (Morse abbreviation).||"dahdidahditdidadidit"||CL|
|Prosign||Matching Voice Procedure Word||Former Code Symbol||Explanation||Defined in|
|VE||General call||▄▄▄▄▄▄▄▄▄▄▄▄▄▄||1937 Royal Navy Signal Card|
|ii||Separative sign break||▄▄▄▄▄▄ ▄▄▄▄▄▄|
|EEEEE||Erase sign (exactly five dots [code for numeral 5], as opposed to today's exactly eight)||▄▄▄▄▄▄▄▄▄▄▄▄|
|e||Further message sign||▄▄▄▄▄▄▄▄▄▄▄▄▄▄|
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