@kilroo said:
Oh, hey, a third meaning. At least, I assume that's short for "in reference," since "in reply" would be more "to" than "of?"
It actually took me a surprisingly long time to realize that most people I encountered read that "RE:" as "REPLY" rather than "REGARDING." Somehow I went for what, in retrospect, seems an astonishingly long time between starting to use email and receiving a FW:.
Actually, where I come from, it's short for Latin 'in re', roughly 'in the matter of' (from res, thing). I strongly suspect that was how it entered the English language too, and the meanings of regarding, referring to, or reply, were later invented by people not aware of the latin origin and meaning.