5 Quantities and units library [quantities]

5.4 Reference [qty.ref]

5.4.4 Unit [qty.unit]

5.4.4.2 Magnitude [qty.unit.mag]

5.4.4.2.1 General [qty.unit.mag.general]

Subclause [qty.unit.mag] specifies the components used to represent the numerical value (IEC 60050, 112-01-29) of a unit with support for powers (IEC 60050, 102-02-08) of real numbers (IEC 60050, 102-02-05).