Prosigns for Morse code
Procedure signs or prosigns are shorthand signals used in Morse code 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 in the 1860s for wired telegraphy. They are distinguished from common Morse abbreviations. Since Morse code communication preceded voice communications by several decades, many of the much older Morse prosigns have exact equivalent procedure words for use in the more recent radio telephony.
In printed material describing their meaning and use, prosigns are represented by either a sequence of dots and dashes, or by an overlined sequence of letters, which, if sent without the normal inter-character spacing, correspond to the prosign symbol.
History
In the early decades of telegraphy, many efficiency improvements were incorporated into operations. One of these was the introduction of Morse symbols called procedure signs or prosigns. Prosigns were not defined by the inventors of Morse code, but were gradually introduced to improve the speed and accuracy of high-volume message handling.Improvements to the legibility of formal written telegraph messages using white space formatting were thus supported by the creation of procedure symbols. Mastery of these Morse code prosigns was important in becoming an efficient telegraph operator.
Notation / representations
There are at least three methods used to represent Morse prosign symbols:- Unique dot/dash sequences, e.g..
- Unique audible sounds, e.g. "Dahdidididah"
- Non-unique printed or written overlined character groups, e.g. '
Because there are no letter boundaries in the transmitted prosigns, their division into letters is arbitrary and may be done in multiple equivalent ways. For example, ' is exactly equivalent to ' and '. Likewise, the well-known prosign ' could just as well be written ', ', or even . Normally, one particular form is used by convention, but some prosigns have multiple forms in common use.
Many Morse code prosigns do not have written or printed textual character representations in the original source information, even if they do represent characters in other contexts. For example, when embedded in text the Morse code sequence represents the "double hyphen" character. When the same code 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. When used as a prosign, there is no actual written or printed character representation or symbol for a new paragraph, other than the two-line white space itself.
Some prosigns are in unofficial use for special characters in languages other than English, for example "Ä" and, neither of which is part of the international standard. Other prosigns are officially designated for both letters and prosigns, such as "+" and, which marks the end of a message. Some genuinely have only one use, such as or , the International Morse prosign that marks the start of a new transmission or new message.
Official International Morse code procedure signs
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, 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 FROM | ITU-R M.1172 ITU-R M.1677-1 | Used to precede the name or other identification of the calling station. | |
| UNKNOWN STATION | International Code of Signals | Used for directional signaling lights, but not in radiotelegraphy. | ||
| NIL | NOTHING HEARD | General-purpose response to any request or inquiry for which the answer is "nothing" or "none" or "not available". Also means "I have no messages for you." | ||
| R | ROGER | ITU-R M.1172 | Means the last transmission has been received, but does not indicate the message was understood or will be complied with. | |
| K | OVER | ITU-R M.1677-1 | Invitation to transmit after terminating the call signal.. | |
| OUT | ITU-R M.1172 ITU-R M.1677-1 | End of transmission / End of message / End of telegram. | ||
| CL | CLOSING | ITU-R M.1172 | Announcing station shutdown. | |
| CQ | CQ | ITU-R M.1172 | General call to any station. | |
| 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? | ||
| WAIT | ITU-R M. 1170 ITU-R M.1172 ITU-R M.1677-1 | "I must pause for a few minutes." Also means "I am engaged in a contact with another station ; please wait quietly." | ||
| WAIT OUT | ACP 124 | I must pause for a more than a few minutes. | ||
| Verified | ITU-R M.1677-1 | Message is verified. | ||
| QRS | SPEAK SLOWER | |||
| 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 refer is all that follows the text... | |
| AB | ALL BEFORE | ITU-R M.1172 | The portion of the message to which I refer is all that precedes the text... | |
| BN | ALL BETWEEN | ITU-R M.1172 | The portion of the message to which I refer is all that falls between... and... | |
| ? | SAY AGAIN | ITU-R M.1677-1 ACP 124 | When standing alone, a note of interrogation or request for repetition of a transmission not understood. When ? is placed after a coded signal, modifies the code to be a question or request. | |
| INTERROGATIVE | ACP124, ACP131, Radiotelegraph Operations Guide | Military replacement for the ? prosign; equivalent to Spanish ¿ punctuation mark. When placed before a signal, modifies the signal to be a question/request. | ||
| CORRECTION | ITU-R M.1677-1 | Preceding text was in error. The following is the corrected text. | ||
| C | CORRECT / AFFIRMATIVE | ITU-R M.1172 | Answer to prior question is "yes". | |
| N | NEGATIVE | International Code of Signals ACP 131 | Answer to prior question is "no". | |
| ZWF | WRONG | Your last transmission was wrong. The correct version is... | ||
| DISREGARD THIS TRANSMISSION; OUT | The entire message just sent is in error, disregard it. | |||
| QTR? | REQUEST TIME CHECK | Time-check request. / What is the correct time? | ||
| QTR | TIME | The following is the correct UTC in HHMM 24-hour format | ||
| BREAK | ITU-R M.1172 ITU-R M.1677-1 | Start new section of message. Same as character = or – –. | ||
| BK | BREAK-IN | ITU-R M.1172 | Signal used to interrupt a transmission already in progress. AX in ACP131. In military networks is used instead. | |
| ATTENTION | ITU-R M.1172 ITU-R M.1677-1 | Message begins / Start of work / New message | ||
| CFM | I ACKNOWLEDGE | ITU-R M.1172 | Message received. | |
| WX | ITU-R M.1172 | Weather report follows. | ||
| INTERCO | INTERCO | ITU-R M.1172 | International Code of Signals groups follow. |
Morse code prosigns for message handling and formatting in Amateur Radio NTS nets
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 |
| Start new line | Space down one line; typewritten as Carriage Return, Line Feed. Also written. | "didahdidah" | Ä, Á | ||
| Message separator, start new message / telegram. | New Page, space down several lines. Decoder software may show "+". Alternative for "Break" in conversational Morse. Also written. | "didahdidahdit" | + | ||
| Wait | Respond with:, or characters "R" or "C". | "didahdididit" | & | ||
| Start of new section / new paragraph. | Space down two lines; typewritten CR-LF-LF. Decoder software may show "=". | "dahdidididah" | =, – – | ||
| Start of transmission Start of new message. | Attention commencing transmission. Also written. | "dahdidahdidah" | |||
| Error / correction | Always followed by correct text. Sometimes transcribed as "????". Sometimes written. | "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" | ? | |
| Invitation for named station to transmit | Go ahead, specific named station. Decoder software may show equivalent character " | "didididahdahdahdididit" | |||
| BK | Break in conversation | Morse abbreviation for "back-to you". In conversational Morse some use either,,, or "K" instead. | "dahdididit dadidah" | BK | |
| CL | Closing down | Abbreviation for "closing station". | "dahdidahdit didadidit" | CL''' |