Morse Code Numbers, Punctuation and Prosigns

Once you can copy the 26 letters, the rest of International Morse is small and pleasantly logical. The ten digits follow a single rule you can learn in minutes. A dozen punctuation marks cover almost everything in real traffic. And a handful of special signals called prosigns, plus some well-worn abbreviations, give you the grammar of an actual conversation. This guide covers all of it.

The numbers 0 to 9

Every digit in Morse is exactly five elements long, and the pattern is a simple sliding scale. The digits 1 through 5 start with that many dots followed by dashes to fill five places; 6 through 9 start with dashes and end with dots; and 0 is five dashes.

Read down the table and you can see the dots “filling up” from the left for 1 to 5, then “draining” from the left for 6 to 0. Because all ten are the same length and the shift is so regular, most learners find numbers easier than letters. The one thing to watch is that 5 (five dots) and H (four dots) are close relatives, as are 0 (five dashes) and O (three dashes). Context usually resolves it, and with practice the extra element becomes obvious.

Cut numbers

In fast contest and traffic operating, where numbers are frequent and predictable, operators use abbreviated “cut” numbers: T for 0, A for 1, N for 9 and so on. A signal report of “599” is often sent as “5NN”. These are not part of the official code and should only be used where both sides expect them, but you will hear them constantly on the amateur bands.

Punctuation you will actually use

International Morse defines codes for a range of punctuation marks. Most are six elements long, which makes them slower to send than any letter, so operators use them sparingly. The ones worth learning first are in the table below.

Two things stand out. First, several punctuation codes double as prosigns, which is not a coincidence: the prosigns came first and the punctuation meanings were layered on. Second, the @ sign is the only character added to International Morse in living memory, formally approved by the ITU in 2004 so that operators could exchange email addresses. It is a run-together A and C, sometimes called the “commat”.

You can hear any of these by typing them into our Morse translator. The exclamation mark, by the way, has no official ITU code; the widely used -.-.-- is a convention from amateur practice.

Prosigns: the punctuation of conversation

A prosign, short for procedural signal, is two letters sent as one character with no gap between them. In writing they are shown with a bar over the top or in angle brackets, such as <AR>. They do not spell anything; they tell the other operator what is happening in the exchange. SOS is technically a prosign, which is why it is covered in our SOS article. The ones you will hear in almost every contact are:

Hearing BT is a good sign in a long transmission; it means the operator is collecting their thoughts and you get a moment to catch up. Hearing AR means it is nearly your turn. SK at the end of a contact is often followed by the other station’s callsign and a friendly “73”. Some operators add “dit dit” after SK, an informal sign-off that works something like a wave goodbye.

Ham radio abbreviations

Because every character costs time, radio operators developed a rich shorthand. Unlike prosigns, these are sent as ordinary separate letters. A small vocabulary goes a long way:

The numeric codes 73 and 88 come from the “92 Code”, a list of numbered shorthand messages adopted by Western Union in 1859. Most of the list is forgotten, but 73 survived and became so ingrained that operators say it aloud on voice too. Note that it is already plural in sense, so “73s” is a minor faux pas, though nobody will mind.

A sample exchange

Putting it all together, a short amateur contact might go like this. Station A calls “CQ CQ CQ DE A1AA A1AA K”. Station B answers “A1AA DE B2BB B2BB KN”. A replies “B2BB DE A1AA <BT> TU FER CALL UR RST 599 5NN <BT> QTH LONDON <BT> HW? <AR> B2BB DE A1AA KN”. B sends a similar report back, and the contact closes with “73 ES TU <SK> A1AA DE B2BB”. Every element in that exchange is something from this article: digits, a cut number, three prosigns and half a dozen abbreviations.

If the letters themselves still need work, the alphabet guide and the interactive Morse code chart are the place to start. Numbers and prosigns are the easy part; they are also what turns a list of letters into a conversation.