"SK" meaning Silent Key is not a Morse prosign, it is an initialism as you might use anywhere else in English. The individual letters "S" and "K" are sent separ

"SK" meaning Silent Key is not a Morse prosign, it is an initialism as you might use anywhere else in English. The individual letters "S" and "K" are sent separately just like any other word: ••• —•— or di-di-dit (pause) dah-di-dah There is a prosign <SK> but it has a different meaning - "end of transmission" - and it is sent like this: •••—•— or di-di-di-dah-di-dah A prosign is sent as if it were a single letter, without the pauses you would use between letters. As you might guess, the same prosign could be spelled multiple ways. For example, a prosign named <VA> would be indistinguishable from <SK>, because VA as separate letters would be sent like this: •••— •— or di-di-di-dah (pause) di-dah If you take out the pause you have the exact same thing as <SK> above. Prosigns are customarily typeset with a solid bar over all the letters to indicate they are sent with no pauses as if it were a single letter. When that isn't possible, a prosign may be spelled with angle brackets around it or a similar indication. This may be a subtle distinction, but in the old days it could save your life. If you ever had to send <SOS> in Morse, trained operators would recognize it faster if you sent it correctly as a prosign: •••———••• or di-di-di-dah-dah-dah-di-di-dit instead of sending it incorrectly as individual letters: ••• ——— ••• or di-di-dit (pause) dah-dah-dah (pause) di-di-dit Here is a chart of Morse code characters and prosigns: https://morsecode.scphillips.com/morse.html https://morsecode.scphillips.com/morse.html