I "think" it says (or at least said; I do not know if that remains the case, though it appears so), a Free Fire Zone is "A specific designated area into which any weapon system may fire without additional coordination with the establishing headquarters." Those are the words quoted from the manual at the link I posted (and everywhere else that I have seen.) However, and once again, I never wanted to parse Vietnam, so if you want to withdraw the sidebar you introduced, that is fine with me.