David Bradley explains a dramatic, historic passage in the evolution of the meaning of “billion”:
…In the issue of Nature dated 2nd July 1992, the journal stated: “…from now on, the English word “billion” will be understood as meaning 10^9 rather than 10^12. It is earnestly hoped that readers will not mistake this upheaval in editorial practice for the witless indulgence of innovation for its own sake. Rather it is a case where tradition [of close to 125 years] has been overwhelmed by others’ usage.”…
Anon (1992). Billion bites the dust Nature, 358 (6381), 2-2 DOI:10.1038/358002b0