Or rx, tx, wkg, and lots of others I can't remember. All preceeded SMS...
Used to be lots of 'Q' codes originally developed by morse signallers -
If all involved totally and without any time wasted to decipher understand the one and only interpretation og the abbreviation, there is no problem.
Your example with ham radio actually illustrates exactly what the issue is: if all involved are radio amateurs, use radio amateur abbreviations if you wish, if even ONE is not fluent in those, do not use them. As all involved here (are supposed to) understand microcontrolers use microcontroller/electronic abbreviations and none other. It would be defeating the purpose to use "move external" instead of MOVX in explaining a piece of assembly, but there is no requirement that an electronic engineer for whom 'r' stand for resistance/resistor should be able to decipher in which case that is so and in which cases it stands for "are". There have been threads that got totally off track because someone was too lazy to add two letters to 'r'.

Some "defences" for '-ve' have been posted "it has been around for ages", but who knows if it has ever "been around" in e.g. Slovakia. A bit of consideration for the international nature of this forum should be displayed when posting.

There are some with english as their native language that have no problem with SMS, that is one thing, I, for one, take 'u' as meaning 'micro' and 'r' as meaning resistance. Then after having read the whole sentence I say to myself "that can't be it" and go back and spend time trying to figure out what it really means.

Erik