The pattern behind the numbers
All ten digits are five elements long, which makes them easy to tell apart from letters. Starting from 1 (-----), each digit swaps one leading dot into the dash group until 5 is five dots (....-); 6 to 0 then fill up with dashes from the front, ending with 0 as five dashes (----.). Contest operators often shorten numbers they send constantly — N for 9 and T for 0, so a signal report of 599 becomes 5NN — but these “cut numbers” are an amateur convention, not part of the ITU table.
Signs the ITU tells you to spell
ITU-R M.1677-1 gives instructions for signs that have no signal of their own: the multiplication sign is sent as the letter X, and percent as 0/0 joined to the number by a hyphen (..--- -....- ----- -..-. ----- for “2%”). Inverted commas (quotation marks) have their own signal, sent before and after the quoted words; for minutes and seconds after a number, the apostrophe is used once or twice.
Prosigns are single characters
A prosign is several letters run together without the usual letter gap. Several share their signal with punctuation — AR is the + sign, BT is the = sign — so context tells you which is meant. In the translator, type a prosign in angle brackets, such as <SK>, to send it as one character.
Sources
- Recommendation ITU-R M.1677-1 (10/2009), International Morse code — Annex 1, §1.1.2 Figures, §1.1.3 Punctuation and miscellaneous signs, §3 signs without a Morse signal
- Recommendation ITU-R M.1172 — Miscellaneous abbreviations and signals (AR, AS, BT, K, KA, VA)
- Rochester (NY) Amateur Radio Association — Common CW Abbreviations (cut numbers N = 9, T = 0)