Reference Plant Ontologies are being developed in the context of the Planteome project and are being integrated with the Crop Ontology, which provides harmonized breeders’ trait names, measurement methods, scales and standard variables for many crops. The Country and Location Ontology is one of these reference ontologies integrated within the Crop Ontology. It has been adapted from ISO 3166-1 country codes and covers the official ISO 3166-1 alpha-2, alpha-3 and numeric country codes.