CW Abbreviations and Prosigns: Reading the Code on the Air

Listen to two operators on CW for a minute and the exchange sounds like a private language: CQ DE LY4A K, GM OM TNX FER CALL UR RST 579 ES NAME IS JONAS HW CPY, 73 TU SK. It is a language, but a small one, and you can learn it in a few evenings. These CW abbreviations exist for a good reason. They shorten transmissions when conditions are poor, they work between operators who share no spoken language, and they have been refined by more than a century of practice. This guide lists the ones you will actually hear, explains the prosigns that control a conversation, and walks through a complete contact so you can see how it all fits together.

Learning abbreviations is the second step in learning to operate CW, after you can copy letters and numbers comfortably. If you are still working on that first step, our guide to learning Morse code and building CW speed covers it.

Where These Abbreviations Come From

Many abbreviations date from the days of commercial and maritime telegraphy, when operators were paid by the word or by the minute and brevity mattered. Amateurs adopted what they found useful and added their own. Some are plain contractions, such as PWR for power or ANT for antenna. Some are borrowed from the Q code, a set of three-letter signals beginning with Q that each mean a sentence, as in QTH for location. We cover those separately in our article on ham radio Q codes. Others are conventions that grew up on the air and are not official, such as FB for fine business, meaning good or excellent.

There is no single authoritative list, and usage varies by region and by operator. Treat any list, including this one, as a guide to common practice rather than a rulebook. The formal part is the character set and the procedural signals. The ITU maintains the international Morse code recommendation, ITU-R M.1677, which defines the characters and the procedural signals used in international Morse transmissions. The abbreviations built on top of that are tradition.

Prosigns: The Punctuation of CW

A prosign, short for procedural sign, is a group of letters sent together with no gap between them, so that they sound like one character. Prosigns are written with a bar over the letters, or with the letters joined by a character such as an equals sign, because they are single signals and not two letters. They control the flow of a conversation, the way a speaker says over or out.

The full set of prosigns and their variants is described in the article on Morse code prosigns. A few of them behave differently in ordinary conversation than the formal definitions suggest, so listen to how operators actually use them. K and KN are the pair that cause the most confusion. Sending K at the end of your over invites any station to call, which is correct when you are calling CQ. In a QSO, KN tells everyone else to stay out, and that is the polite signal when you are in the middle of a contact on a busy band.

Everyday Abbreviations You Will Hear

The following groups cover most of what appears in a routine contact. They are common, not universal.

Greetings and courtesy

• GM, GA, GE, GN: good morning, good afternoon, good evening, good night.
• TU, TNX, TKS: thank you, thanks.
• PSE, PLS: please.
• SRI: sorry.
• GL: good luck.
• 73: best regards, the standard sign-off. Operators using very low power sometimes send 72.
• 88: love and kisses, used between friends, and often to a female operator.

People and the station

• OM: old man, a friendly term for a male operator. YL: young lady, a female operator. XYL: wife.
• OP: operator, as in OP IS JONAS. NAME and QTH give your first name and location.
• RIG: transmitter and receiver. ANT: antenna. PWR: power. WX: weather. TEMP: temperature.
• HR: here. UR: your, or you are.

Conversation and copy

• ES: and. FB: fine business, meaning excellent. FER: for. WID: with. ABT: about. B4: before.
• AGN: again. Used as in PSE AGN to ask for a repeat.
• CPY: copy. HW CPY: how do you copy me.
• R: received, understood. NW: now. WKD: worked.
• VY: very. HPE: hope. CUL: see you later. CUAGN: see you again.
• HI: the sound of laughter in CW, used instead of a smiling face.
• DX: long distance, usually another country. SKED: a scheduled contact.

Signal reports use the RST system, with numbers for readability, strength and tone. In contests the numbers are often shortened, for example 5NN for 599, which we explain in our guide to cut numbers and CW contest exchanges.

A Complete Contact, Line by Line

This is a typical ragchew start at moderate speed. The text is what you would send, with the prosigns marked, and the notes explain each part.

1. The CQ call: CQ CQ CQ DE LY4A LY4A LY4A K. Three CQs, your callsign sent three times after DE (from), then K to invite any station. Keep it short if the band is busy.
2. The answer: LY4A DE OH2XYZ OH2XYZ K. The replying station sends your call once, DE, then its own callsign, and K.
3. The first over: OH2XYZ DE LY4A GM OM TNX FER CALL UR RST 579 579 ES NAME IS JONAS JONAS QTH VILNIUS HW CPY AR OH2XYZ DE LY4A KN. The report comes first, then the name and location, a request for confirmation and the AR prosign, finishing with the other callsign and KN.
4. The reply: LY4A DE OH2XYZ R GM JONAS TNX FER RPRT UR RST 589 ES NAME HERE IS MIKA MIKA QTH ESPOO RIG HR HOMEBREW PWR 100W ANT DIPOLE BT WX HR CLOUDY ES COLD HW? LY4A DE OH2XYZ KN. Note the BT between the equipment and the weather, and the question mark at the end of a question.
5. The sign-off: OH2XYZ DE LY4A R FB MIKA TNX FER NICE QSO ES 73 CUAGN SK OH2XYZ DE LY4A. A friendly close, 73, SK for the end of the contact and a final identification.
6. The confirmation: LY4A DE OH2XYZ R 73 TU SK. The other station returns the compliment and signs off.

Two points from the example are worth noting. First, the callsigns are sent often, because on a crowded band the other station may be unsure who is calling. Second, the structure is flexible. Some operators send a short exchange of reports and sign off within a minute, while others spend an hour on weather, equipment and family. Both are fine.

Common Confusions When Copying

Beginners trip over a few look-alikes. AR and RA are different: only the first is a prosign, sent as one unbroken signal. SK sent as a prosign ends a contact, while the letters S and K sent separately are just letters. AS asks the other station to wait, and it is easy to mistake for the start of a word. In a callsign, the letter O and the number zero can both be sent as a long dash group in a hurry, so context decides. Numbers sent as cut numbers, for example a T for zero or an N for nine, are normal in contests and confusing on first hearing. When in doubt, ask for a repeat with AGN or PSE AGN, or send a question mark after the part you missed. Asking is never rude on CW, and every experienced operator has done it many times.

Abbreviations in Contests

A contest exchange strips the conversation to the minimum. Most of the shorthand above disappears, and the stations exchange a callsign, a report and a serial number or a zone. Typical signals are TU for thanks, QRZ to ask who is calling, AGN to request a repeat and sometimes a plain question mark. You will hear 5NN in place of 599, and cut numbers for digits in the serial number. Our guide to weekly CW contests for practice gives you a safe place to practise at speed without a live pileup.

Good Habits When Using Abbreviations

• Do not overdo it. A message that is all abbreviations is harder to copy than plain text for a beginner. Use common ones and spell out anything unusual.
• Send a question mark after a question. HW CPY needs it, and so does anything else you are asking.
• Match the other station’s style. If the other operator uses plain English and few abbreviations, follow suit. If they send fast and clipped, they will probably be comfortable with the same from you.
• Do not make up your own. A private abbreviation gives the other station nothing to decode. Stick to the common set.
• Slow down for new operators. A station that sends slowly and in plain text is often a new CW operator. Replying at their speed is both kind and the quickest way to a pleasant contact.
• Identify properly. Send your callsign at the start and the end of the contact and at the intervals your licence requires. The requirements vary between countries, so check your own rules.

Learning Abbreviations Efficiently

The fastest way to learn them is to hear them used. Listen to ordinary QSOs, either on the air or from a recording, and write down what you copy. Notice that a handful of abbreviations account for most of the use. Start with CQ, DE, K, R, TU, 73, ES, FB, AGN, PSE and the signal report words. After a week of listening, add RIG, ANT, PWR, WX, QTH and NAME. Practise sending them with a paddle or a key as well as copying them, because the rhythm of a prosign is something your hand must learn. Our guide to iambic keying and keyer setup covers the sending side.

The Bottom Line

CW abbreviations are a small, practical shorthand: a few dozen terms cover almost every ordinary contact. Prosigns such as K, KN, AR, SK and BT control the conversation, and a typical QSO follows a fixed shape of CQ, exchange, exchange, sign-off. Learn the core set by listening, use plain text when in doubt and remember that the aim is to be understood, not to be clever. Within a few contacts the language stops being a barrier and starts to feel like conversation.

Frequently Asked Questions

What does SK mean in CW?

SK is the prosign for the end of a contact. It is sent as a single signal, not as two letters, and tells the other station you have finished. Many operators follow it with the other callsign and their own as a final identification.

What is the difference between K and KN?

K invites any station to transmit, so it is used when calling CQ. KN invites only the named station to transmit, which tells others on the frequency that you are in a contact and do not want a break-in.

What does AR mean?

AR is the prosign for the end of a message. Operators often use it at the end of a CQ call or a longer transmission, followed by the other callsign and K or KN.

Are CW abbreviations official?

Only partly. The characters and the procedural signals are defined in the international Morse code recommendation. Most conversational abbreviations, such as FB and ES, are tradition and vary by region and operator.

Is it rude to use plain English on CW?

No. Many operators prefer plain text, especially when speaking with a newer CW operator or a station that sends slowly. Use the common abbreviations that help and spell out anything the other operator might not know.

How many abbreviations do I need to learn?

Around twenty or thirty cover most routine contacts, including CQ, DE, K, KN, AR, SK, R, TU, 73, ES, FB, AGN, PSE, NAME, QTH, RIG, ANT, PWR and WX. Learn them by listening to real QSOs and add others as you meet them.