> For the complete documentation index, see [llms.txt](https://fairsharing.gitbook.io/fairsharing/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://fairsharing.gitbook.io/fairsharing/record-sections-and-fields/general-information/identifier-type.md).

# Identifier Type

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**Why is this important?**

[GUPRIs](/fairsharing/record-sections-and-fields/general-information/globally-unique-persistent-and-resolvable-identifier-schemas.md) (and identifier schemas that have some combination of these qualities) enable databases to identify and reference their digital objects consistently over time. Recording the identifier schemes used by your database helps researchers understand how your data can be cited, linked and integrated with other resources.

**FAIR:** Supports **Findability** by documenting the identifier schemes used within your database.
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The identifier type field is applicable to our **database** registry only.
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Providing the type of identifier system your database uses is **mandatory** for all database records.

*Please also see the general information regarding our* [*minimal curation requirements*](/fairsharing/record-sections-and-fields/how-to-update-a-record.md#minimal-curation-requirements)*.*
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Unambiguous identification of database content is important both for alignment with the FAIR Principles and for referencing and attribution of individual datasets within a database.

FAIRsharing **requires** that each database record provide the type of identifier(s) used in one of two ways:

1. Add the standardised persistent identifier schema to your record via the [Relationships](/fairsharing/associated-records.md) tab with the ***implements*** relationship type. An example is [Dryad](https://doi.org/10.25504/FAIRsharing.wkggtx), which ***implements*** the [DOI](https://doi.org/10.25504/FAIRsharing.hFLKCn) identifier schema. The ***implements*** relationship should only be used for the IDs minted/created by the database. To use this option, your database will either mint these identifiers for a) all or b) some of its records. For example, if DOIs are only created upon request (as is the case for some institutional repositories), you may still add a relationship to DOIs.
2. Tick the box in the [General Information](/fairsharing/record-sections-and-fields/general-information.md) tab that confirms that the database uses an internal identifier schema, and therefore will not require a relationship to the appropriate identifier schema as outlined in item 1.  An example is [OpenBiodiv](https://fairsharing.org/3818), which uses internal identifiers such as <https://openbiodiv.net/5f324c6b-d93e-4ff4-b123-ba3f9e293d68>.

For more information on the identifier schemas registered with FAIRsharing, please see our [note on identifier schema records](/fairsharing/record-sections-and-fields/general-information/registry-type.md#a-note-on-identifier-schema-records).