The atomic weights used in computing molecular weights and the factors in the assays and elsewhere are those recommended in 1997by the IUPAC Commission on Atomic Weights and Isotopic Abundances.Chemical formulas,other than those in the Definitions,tests,and assays,are given for purposes of information and calculation.The format within a given monograph is such that after the official title,the primarily informational portions of the text appear first,followed by the text comprising requirements,the latter section of the monograph being introduced by a boldface double-arrow symbol ».(Graphic formulas and chemical nomenclature provided as information in the individual monographs are discussed in the Preface.)