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The ontology developers should document that the ontology is used by multiple independent people or organizations.


This principle aims to ensure that the ontology tackles a relevant scientific area and does so in a usable and sustainable fashion.

Recommendations and Requirements

It is important to be able to illustrate usage outside of the immediate circle of ontology developers and stakeholders. Note that the ontology can still be listed on the OBO Foundry website while publicising your resource in appropriate channels and searching for users with needs you can meet.


The ontology developers should provide links/citations to evidence of use (publication, external ontology; see examples below for additional types) within your ontology metadata file (replacing with the correct group name, link, and description):

- user: http://www.informatics.jax.org/disease (link to group)
  description: MGI disease model annotations use DO (description of group)
   - url: http://www.informatics.jax.org/disease/DOID:4123 (link to specific example)
     description: Human genes and mouse homology associated with nail diseases (description of specific example)

You may have multiple examples for each user, and mulitple users under the usages tag.


  • Use of the target ontology’s term IRIs in other ontologies. This can be evidenced by linking to the other ontology that uses an ontology term IRI from this ontology

  • Imports in other ontologies, again, evidenced through a link to the importing ontology

  • A documentation page with links to databases using the ontology for annotation

  • Use in semantic web projects (e.g., Open PHACTS usage)

  • Use in diverse software applications, including text mining or analysis pipelines

  • Publications showing the ontology being used in research (evidenced by citation details for the publications; if behind paywall it may be necessary to provide a PDF for the paper)

  • Citations to the ontology publication(s); such citations are only relevant if the authors indicate actual use of the cited ontology within some community (mere mention of the existence is not enough to warrant inclusion)

  • Documentation of requests from multiple users, e.g., via an issue tracker (provide a link to the issue tracker online)

  • Use of the terms from the ontology to structure or annotate experimental or derived data (e.g. GOA; provide details of how to review the annotations)


Mere mention of the existence of an ontology in a publication is not enough to count as evidence of usage

Criteria for Review

Ontology developers must demonstrate at least three external users specified within the metadata file. External users are defined either as researchers not significantly overlapping in personnel with the developers or three independent groups with three independent artefacts (db, etc) that use the ontology. Note that new ontologies are not expected to have a plurality of users, and thus the automatic evaluation of this criterion can be ignored.

This check is automatically validated.

Feedback and Discussion

To suggest revisions or begin a discussion pertaining to this principle, please create an issue on GitHub.

To suggest revisions or begin a discussion pertaining to the automated validation of this principle, please create an issue on GitHub.