| An xref to an organism taxonomy database, preferably NCBI taxon. This should be an instance of unificationXref, unless the organism is not in an existing database. |
| owl:ObjectProperty |
ObjectProperty(TAXON-XREF annotation(rdfs:comment "An xref to an organism taxonomy database, preferably NCBI taxon. This should be an instance of unificationXref, unless the organism is not in an existing database."^^<http://www.w3.org/2001/XMLSchema#string>)
domain(bioSource)
range(xref))