certified nominal reference material

https://doi.org/10.1351/goldbook.10035

Nominal reference material accompanied by documentation issued by an authoritative body and providing one or more specified nominal property values with examination uncertainty and examination traceability, using valid examination procedures.

Source:
PAC, 2018, 90, 913. 'Vocabulary on nominal property, examination, and related concepts for clinical laboratory sciences (IFCC-IUPAC Recommendations 2017)' on page 932 (https://doi.org/10.1515/pac-2011-0613)