https://doi.org/10.1351/goldbook.15375
Deprecated term that includes both a quantity and a unit. Replace by mass fraction expressed as percent.
Example: Deprecated: the solubility of \(\ce{B}\) is \(\pu{2.5 mass \%}\). Recommended: the solubility of \(\ce{B}\) is \(w_{\ce{B}} = 0.025\), or \(w_{\ce{B}} = \pu{2.5\%}\), or (especially in table headings and labels on axes of plots) \(100 w_{\ce{B}}\), with entry \(\pu{2.5}\) in table or on axis.