Talk:Proven reserves

only fossil fuels?
Does the term proven reserve apply only to fossil fues, as the lede claims, or does it refer to any extracted resource? The section of Helium mentions proven reserves of helium and id like to link that here, but im not sure that is proper. The citation for the first sentence in the lede seems to be dead so i cant check there. Any thoughts/replacement citations? Bonewah (talk) 13:14, 31 August 2021 (UTC)