Each transmission session ends with certain codes. Over time, they become routine, but in order not to be remembered by mistakes, it is very important to use them correctly from the beginning, since there are certain nuances.
Codes transmitted at the end of a session:
| CODE | MEANING | USE |
| AR | End of transmission. Means only “end of transmission” and nothing else. | Transmitted at the end of CQ and at the end of your transmission when you call station(1). |
| K | End of transmission and I turn it over to you. It’s your turn! | At the end of an “over” (2) (reply) and at the end of your transmission when calling a station. I expect to receive. |
| KN | I transfer only to you, please others wait for SK (see below). | At the end of an “over” (reply). Others must wait for the current QSO to be completely completed, without interfering. |
| BK | Interrupt, break. Not transmitted in a merged form. | To interrupt someone else’s or your own reply. It is not transmitted in a merged form. It is used for greater efficiency, as when working “on break” initials are not transmitted at the end and beginning of each line. |
| AR K | End of transmission + I’m transferring it only to you. | DO NOT use it. Bad practice. |
| AR KN | End of transmission + I’m transferring it only to you | DO NOT use it. Bad practice. |
| SK | Complete end of the QSO. | At the end of the QSO. Gives others the freedom to call the station originally using the frequency. |
| AR SK | End of transmission + end of the QSO. | DO NOT use it. Bad practice. |
| SK CL | End of QSO, I am turning off the station and will not respond to other correspondents. | Used when you are terminating work and will not respond to anyone anymore. |
(1) when responding to a station that has called CQ or QRZ.
(2) transmission or over (replica) is not the same as QSO (two way radio communication). A QSO usually consists of a series of overs.
Transmitting “DIT DIT” at the end of a QSO on CW
At the end of the QSO on CW, the two partners in the connection often exchange as the last code two DITs with a slightly longer interval between them (similar to “e e”). This is not an official code, it means and sounds like the colloquial “bye-bye”.
