Andrew, like you I ‘grew up’ with, learnt and used most of the Q codes, prosigns and ham abbreviations but sadly I think we are fighting a losing battle.
So nowadays, I’m reluctant to use the less-frequently used ones in a QSO with an op who clearly doesn’t appear to know them. Of course, this leads to less efficient communications [in terms of characters sent] but clarity of meaning is uppermost in my mind. It’s like with experts, they can talk in jargon for efficiency but need to use plain language when talking to non-experts.
73 [there I go again when it’s written English]
Andy