Editing International System of Units (section)

=== Unacceptable uses ===

Sometimes, SI unit name variations are introduced, mixing information about the corresponding physical quantity or the conditions of its measurement; however, this practice is unacceptable with the SI. "Unacceptability of mixing information with units: When one gives the value of a quantity, any information concerning the quantity or its conditions of measurement must be presented in such a way as not to be associated with the unit."<ref name="SIBrochure"/>
Instances include: "[[watt-peak]]" and "[[watt RMS]]"; "[[geopotential metre]]" and "[[vertical metre]]"; "[[standard cubic metre]]"; "[[atomic second]]", "[[ephemeris second]]", and "[[sidereal second]]".