Content & context: 3. Select identifier schemes

This step defines what needs to be assigned an identifier and selects appropriate identifier schemes. Established identifiers should be reused where possible, with new unique, persistent and resolvable identifiers introduced only where required.

Identifiers allow research objects, their versions, components and the entities they describe to be referenced unambiguously across systems and over time. Appropriate identifiers support discovery, citation, provenance, linking, integration and reproducibility.

A FAIRification activity may require several identifier schemes. Different schemes may be appropriate for the research object as a whole, individual objects, versions, components, domain entities, people, organisations, instruments and related resources.

This step builds on the research object inventory established in Step 1 and the types, relationships and domain model defined in Step 2. These determine what needs to be identified, at what level of granularity and for which intended uses.

An identifier scheme includes more than the identifier’s syntax. It also includes its namespace, issuing authority, uniqueness scope, resolution mechanism, persistence commitment and lifecycle policy. Not every internal component requires a globally resolvable persistent identifier. The level of identification should be proportionate to the intended uses, while ensuring that research objects and components that need to be independently discovered, cited, accessed, versioned or referenced can be identified reliably.

Use this step during project examination to inventory existing identifiers, define identifier requirements, assess candidate schemes and identify dependencies. During an implementation cycle, use it to reuse established identifiers, mint new identifiers where needed and validate the resulting identification and resolution arrangements.

Identifier minting

Create, assign and register new identifiers—unique, persistent and resolvable.

This capability is required when no suitable established identifier exists or when a new research object, version or independently identifiable component is created. It includes selecting an appropriate identifier scheme and issuing authority; preventing duplicate assignment; associating identifiers with the correct subjects and metadata; and supporting the required resolution, persistence, versioning and lifecycle arrangements.

Identifier minting would normally be provided by a repository, registry, institutional service or infrastructure provider rather than brought in by the FAIRification team itself.

Resources

Identifier discovery and reuse

Recognise, assess, retain and apply established identifiers for research objects, components and domain entities.

This capability enables consistent identification across systems and communities. It relies on and preserves existing links, avoids duplicate identities and enables information about the same subject to be connected across research objects, repositories, services and workflows. Identifier reuse may depend on external authorities, registries, repositories, lookup services or community expertise. It includes determining what existing identifiers represent, whether they are suitable for reuse and how they should be used and referenced in the FAIRification activity.

Resources