In English is largely synonymous with @O04365@, and may be preferred when the value represents a mere parameter or number rather than being related to chemical systematics or a state of the atom in a compound. Etymologically, it stems from the no-longer-used term @S06020@ (oxidation number of a @C00930@; the charge it would bear if all the ligands were removed along with the electron pairs that were shared with the @C00930@) and the likewise obsolete term @E02231@ (ion charge).
PAC, 2014, 86, 1017. (Toward a Comprehensive Definition of Oxidation State) on page 1020-1021 [Terms] [Paper]
PAC, 2016, 88, 831. (Comprehensive definition of oxidation state) on page 832 [Terms] [Paper]