The problem with this particular one is that, to many people, the meaning of the phrase (in terms of everyday English) may appear so 'obvious' that, despite what you say, they won't even suspect that they are making an 'assumption'. ... We all know the meaning of 'sugar free', 'additive free', 'toxin free', 'lead free', 'gluten free', 'nut free' 'maintenance free', 'surcharge free', 'toll free', 'postage free' etc. etc. etc.- and if I threw an unfamilar 'X free' at members of the general public, most would automatically believe that they knew what it meant - so why should they think they're making an assumption when they believe that they know the meaning of "volt free"? If 'nut free' was used by food manufacturers to mean something other than 'the obvious', there would probably be deaths as a result. One has to wonder about "volt free".How about people finding out what "volt free" (or any other term which they know they don't know what it means) means rather than thinking it's OK to do circuit design on the basis of ignorant assumptions?how about something like 'isolated' or 'independent'?
Maybe, but that's getting very close to the only-too-common 'arrogance' (or 'protectionism') of so many trades and professions, which seemingly want to maintain mysticism and make it more difficult for 'outsiders' to understand their 'languiage'/jargon - in other words, they sometimes seem to want outsiders to remain 'ignorant' and hence erect obstacles to 'non-ignorance'. I don't condone that - do you?It really doesn't matter how you try and spin it, every one of your "yes but it's confusing to the ignorant" simply reinforces the position that the ignorant should not fiddle.
The other issue here, of course, is that I'm quite sure that at least some electricians won't be familiar with the sense in which "volt free" is being used in this context - so it's not even just 'ignorant outsiders'.
Kind Regards, John