Recommendations for clinical laboratory science reports regarding properties, units, and symbols: the NPU format.

The document describes the Nomenclature for Properties and Units (NPU) format developed by the joint committee on Nomenclature for Properties and Units of the IFCC and IUPAC. Basic concepts, in particular system, component, kind-of-property, and unit are defined. Generalities concerning quantities and units, and terminological rules are recalled. A constant format is structured for reporting clinical laboratory information. It is adapted for examinations, including measurements, performed in the clinical laboratories. The NPU format follows international recommendations. Using this format, more than 16,000 properties examined in the clinical laboratories have been described. A regularly updated version of the descriptions is available from the IFCC. Examples from different disciplines are given to promote the dissemination of the format. The object of the NPU format is the transfer of examination data without loss of accuracy between the laboratory personnel and the clinicians. The format is well-adapted for comparative and epidemiological studies.