Morse code abbreviations are shortened sequences of dots and dashes, or combinations of letters, that convey specific procedural meanings, frequently used in telegraphy and radio communication. They are implemented to increase transmission efficiency and to standardize common messages. The abbreviations fall into several categories:
1. Prosigns (procedural signals)
These are special characters transmitted as a single, uninterrupted sequence of elements, and they indicate operational instructions rather than textual content. Common prosigns include:
| Prosign | Morse representation | Meaning |
|---|---|---|
| AR | .-.-. | End of message (also “stop” sign) |
| AS | .-... | Wait (used to pause transmission) |
| SK | …-.- | End of work / signing off |
| KN | -.-.-- | Invitation to transmit (used in two‑station exchanges) |
| BT | -...- | Separator (often used to mark a new paragraph) |
| HH | ........ | Indication of a break or pause (used in some procedural contexts) |
2. Standard abbreviations for frequent words or phrases
These consist of standard letters sent in their usual Morse form, but they represent whole words or phrases. Examples include:
| Abbreviation | Full form | Typical usage |
|---|---|---|
| OM | Old Man (a fellow radio operator) | Conversational |
| TNX | Thanks | Acknowledgment |
| 73 | Best regards | Sign‑off in amateur radio |
| 88 | Love and kisses | Personal sign‑off |
| CQ | Calling any station | General call for contact |
3. Q‑codes
Although originally designed for radiotelegraphy in aviation and maritime services, Q‑codes are three‑letter abbreviations beginning with “Q” that convey specific queries or statements. They are transmitted in Morse and are widely used by amateur radio operators. Selected examples:
| Q‑code | Meaning | Example usage |
|---|---|---|
| QTH | My location is … | “QTH New York” |
| QRM | I am experiencing interference | “QRM?” (question) |
| QRZ | Who is calling me? | “QRZ?” |
| QSL | I acknowledge receipt | “QSL” (affirmative) |
Historical background
The practice of using abbreviations in Morse code dates to the early era of wired telegraphy in the 19th century, when operators created shorthand to reduce transmission time and cost. Formalized sets of prosigns and abbreviations were later standardized by international bodies such as the International Telecommunication Union (ITU). During World War II, additional procedural signals were introduced for military communications, many of which persisted into civilian and amateur radio use after the war.
Current relevance
In contemporary amateur radio, Morse code (continuous wave, CW) remains a licensed mode in many jurisdictions. Operators continue to employ the established abbreviations to facilitate rapid exchanges, especially during contests and “DX” (long‑distance) contacts. The ITU’s “Radio Regulations” still list the core prosigns as part of the standardized international Morse code repertoire.
References
- International Telecommunication Union, Radio Regulations, Section 5. (Official list of prosigns).
- Wikipedia, “Morse code prosign” (accessed 2026).
- ARRL (American Radio Relay League), ARRL Handbook for Radio Communications (latest edition).
