Alternative notation. A subscript can be substituted for an underbar; if there is a parallel construction between overbars and underbars, a corresponding superscript may be used to indicate the overbar. Embellishments over symbols may be replaced by superscripts following the symbol. Minus signs and tildes are often used for this purpose.
Except for the vector notation or underlined letters, the copy editor usually consults the author before using one of the alternative notations suggested.
