Scope The ontologies should have a clearly specified scope (the domain it intends to cover). Have textual definitions The ontologies should have textual definitions for each item, in a human-readable way. That means that beside the alphanumeric identification for each item, they should be described in natural language by logical affirmations following the Aristotelian logic in a way that is unique within the ontology. Standardized relations and the Relation Ontology (RO) The ontologies should use relations between items from the Relations Ontology (RO). This ensures that different ontologies can integrated seamlessly, which is specially important for logical inference. The Relation Ontology (RO) is an ontology designed to represent the relationships between different biomedical concepts. It describes rigorously relations like "part_of", "located_in" and "preceded_by" that are reused by many OBO Foundry ontologies. Documentation OBO ontologies need to be thoroughly documented. Frequently this is done via GitHub repositories for each specific ontologies (see List of OBO Foundry ontologies). Plurality of users The ontologies should be useful for multiple different people, and ontology developers should document the evidence of use. This criterion is important for the review process. Examples of use include linking to terms by other ontologies, use in semantic web projects, use in annotations or other research applications. Openness to collaborations The ontologies should be developed in a way that allows collaborations with other OBO Foundry members. Locus of authority The ontologies should have one person responsible for the ontology who mediates interaction with the community. Naming conventions Naming conventions for OBO ontologies aim at making primary labels unambiguous and unique inside the ontology (and preferably, inside OBO). Labels and synonyms should be written in English, avoiding the use of underscores and camel case. OBO lacks a mechanism for multilingual support, in contrast to Wikidata, which allows labels in different systems. The naming system in OBO is based on a series of surveys at cataloguing naming conventions of current ontologies, as well as discover issues relating to these conventions. Maintenance The ontologies should be updated with regards to changes in scientific consensus. The OBO Foundry defines scientific consensus as "multiple publications by independent labs over a year come to the same conclusion, and there is no or limited (<10%) dissenting opinions published in the same time frame." See also Ontology Lookup Service Gene Ontology Consortium Sequence Ontology Generic Model Organism Databases Functional Genomics Data (FGED) Ontology for Biomedical Investigations Plant ontology