Since 2003,[28] the use of spaces as separators (for example: 20000 and 1000000 for "twenty thousand" and "one million") has been officially endorsed by SI/ISO 31-0 standard,[29] as well as by the International Bureau of Weights and Measures and the International Union of Pure and Applied Chemistry (IUPAC),[30][31] the American Medical Association's widely followed AMA Manual of Style, and the Metrication Board, among others.