- Relation Ontology CC0-1.0
Relation Ontology project; original artifact license CC0-1.0 (https://creativecommons.org/publicdomain/zero/1.0/); https://obofoundry.org/ontology/ro.html
http://purl.obolibrary.org/obo/RO_0002533 ; https://purl.obolibrary.org/obo/ro.owl ; snapshot SHA-256 9a3190d49564743aa00f0b0f2e2d9c5fc5673ac7bb3c369284bf490294d42f77 ; exact artifact license https://creativecommons.org/publicdomain/zero/1.0/ ; retrieved 2026-11-07