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Identifiers are unique strings aimed to identify resources.

In research data management, identifiers can include persistent identifiers (PIDs) such as digital object identifiers DOIs, ORCID iDs and the Research Organisation Registry (ROR) to persistently refer to published articles and research datasets or software in repositories and researchers with their affiliation.

Electronic Lab Notebooks (ELNs) and archiving systems typically also use an identifier system. Specific to chemistry, InChI codes serve as a machine-readable identifier for chemical structures. A further example in chemistry is the CAS Registry Number, a proprietary unique identifier assigned to each chemical substance that is indexed in the proprietary CAS database. CAS numbers are widely used in chemical literature and databases, and they are recognized as an international standard.

In terms of the FAIR data principles, identifiers should interlink scientific publications with their corresponding related dataset(s). For example, referring to the DOI of the associated published journal article in a datasets metadata via a related Identifier helps to describe and lend context to the data. Please see the Best Practice article for further details.

Symbols are close relatives to identifiers, but while identifiers require a dubbing process, such as a resolver for PIDs, symbols apply in a more general sense as a mark to represent another entity.

Sources and further information

Main author: ORCID:0000-0003-4480-8661