This issue comes up with regularity. The answer is simple. If you want a direct answer...scroll to the last paragraph of this email.
----- Background -----
Let's play out a scenario from the point of a 3rd party listening to two sides of a valid QSO from the "old days" of voice-based meteor scatter communications:
Man's Voice: CQ W2AAA CQ W2AAA CQ W2AAA Break Woman's Voice: W2AAA K0ZZ W2AAA K0ZZ W2AAA K0ZZBreak Man's Voice: K0ZZ W2AAA K0ZZ W2AAA K0ZZ W2AAA Break Woman's Voice: W2AAA S5 W2AAA S5 W2AAA S5 Break Man's Voice: Roger S5 S4 Roger S5 S4 Roger S5 S4 Break Woman's Voice: Roger S4 73 Roger S4 73 Roger S4 73 Break Man's Voice: Roger Roger Roger Break Woman's Voice: Roger Roger Roger Break Man's Voice: Roger Roger Roger Break Woman's Voice: Roger Roger Roger Break Man's Voice: Roger Roger Roger Break Woman's Voice: Roger Roger Roger Break (silence)
Unless you were part of the QSO or had engaged in this particular agreed upon protocol before, you would have no way to decipher what just happened.
I could explain everything that happened (including the fact that the Man's side of the QSO didn't copy enough to agree that a QSO had occurred during the last exchange and required three repeats until their QSO Protocol was satisfied)... but ultimately, the point is:
A QSO is "valid" when two parties agree to a protocol (or follow an events' established protocol) and follow it to their satisfaction. Doing so honorably is part of the hobby.
Regards, Ev, W2EV Chairman, Rochester VHF Group The Rochester VHF Group