A persistent identifier (PID) is a long-lasting reference to a digital resource. Unlike URLs, which may break, a persistent identifier reliably points to a digital entity.
An ORCID iD is an example of a persistent identifier for a person. ORCID works closely with many other PID organizations to build trusted connections between ORCID iDs and other identifiers.
Persistent Work Identifiers
You may have heard of DOIs (digital object identifiers), which are persistent identifiers for things or entities such as journal articles, books, and datasets. Crossref and DataCite are examples of DOI registrars assigning DOIs for scholarly communication. ORCID supports DOIs, and many, many other PIDs that are used to identify scholarly outputs.
As well as identifying works contributed to, ORCID uses these PID types to identify peer review subjects, i.e. works that were reviewed.
Persistent Identifiers normalization
In version 3 of the API, we apply some additional processing to normalize identifier values, so that they are comparable across systems.
ORCID uses Organization Identifiers to disambiguate organizations in ORCID records, most often for Education and Employment affiliations.
Alongside work identifiers, ORCID has a long history of using ISSN identifiers. Since the very beginning it has been possible for researchers and ORCID members to associate Works with Journals using ISSN ids. ISSN IDs sit alongside other persistent identifiers, such as DOIs and Pubmed IDs within work metadata, and provide an unambiguous connection between the person, the work and the journal.
Peer review group identifiers
ORCID connects researchers with their peer review activity. This allows journals to acknowledge the huge amount of effort put in by researchers that might otherwise go unrecognised. Within the ORCID user interface and metadata, peer reviews are grouped together using persistent identifiers, usually ISSNs.
The ISSN portal has enabled ORCID to look up journal names at the authoritative source. We are using the openly available and machine readable ISSN data to display the name, along with a link to the portal landing page for that journal. This means that ORCID members deal with ISSN when managing their journal names. It means that the names we display are accurate, have a chain of provenance, and are up to date. And it means that individuals browsing the registry can discover more about the journals within records by visiting the ISSN portal directly.
Requesting new persistent identifiers
ORCID allows reference identifiers to be added to works, funding, and peer review items to help uniquely identify them within the ORCID Registry. The ORCID Registry also groups funding, works, and peer review items based on their associated unique identifier in both the user interface and API. We encourage anyone adding data to ORCID records to add as many identifiers as are known.
ORCID member organizations which exchange data via the ORCID API can request the addition of new external identifier types that all ORCID members and registrants can use to identify works. Requesting new identifiers is a benefit available only to ORCID members.