I think in the case of "revert", in the Oxford dictionary, it states the use-case mentioned by juddles as being "Indian English". We are not in India.
Just like when I work with the Port Authority of New York, they often refer to tollways as "turnpikes" - which is archaic English. But it is the word they choose to use. So I also use "turnpike" when speaking with them, in their country. I would have thought that by now, many people that use "revert" would have learned that we don't use it here.
Anyway, my point was not about "revert" - it was a funny little aside, however
My point was about not being able to understand at all.