QNH is not an Acronym. It is an Initialisation. An acronym is when shortened parts of words are joined (eg PanAm, FedEx) whereas an Initialisation uses the first letter from each of the words (eg NATO).
I now claim my prize for best obscure grammar nitpicking rule of the day.
[Edit: actually I’m not sure what QNH is, as on reflection it cannot be an Initialisation either as Pressure does not begin with a Q! Hopefully this will now start a fruitful discussion which will end in someone saying ‘it is all Msobos fault’]