Identifier
Specific attribute that uniquely identifies an object in a dataset. The National Service for Water Data and Reference-dataset Management (Sandre) produces identifiers in the reference datasets. For example, the code of a measuring station is the identifier naming unequivocally that station.
Source:
According to Onema and IOWater
Identifiant:
http://www.glossaire.eaufrance.fr/fr/concept/identifier