Readback and Correction

IMO SMCP says a sufficiently important part of a message can be safeguarded by saying Repeat and giving that part again. This is not a claim that every routine sentence needs a full readback; follow the applicable procedure and concentrate verification on identity, position, channel, time, instruction or other critical data.

If you did not properly hear another station, use Say Again. If you made the mistake, say Mistake, then Correction, then the corrected part. Those two paths keep the source of the error clear.

After a correction, release PTT and listen. The receiving station may still need to repeat or confirm the changed group. A clean correction reduces ambiguity but does not prove that the final value was received.