reference nominal property value

https://doi.org/10.1351/goldbook.09998

Nominal property value used as a basis for comparison with nominal property values of nominal properties of the same kind-of-nominal-property.

Note: A reference nominal property value can be a true nominal property value of an examinand, in which case it is unknown, or a conventional nominal property value, in which case it is known.

Source:
PAC, 2018, 90, 913. 'Vocabulary on nominal property, examination, and related concepts for clinical laboratory sciences (IFCC-IUPAC Recommendations 2017)' on page 922 (https://doi.org/10.1515/pac-2011-0613)