# Type: Ncname _Prefix part of CURIE_ URI: [xsd:string](http://www.w3.org/2001/XMLSchema#string) * [base](https://w3id.org/linkml/base): NCName * [uri](https://w3id.org/linkml/uri): xsd:string * [repr](https://w3id.org/linkml/repr): str ## Identifier and Mapping Information ### Schema Source * from schema: https://w3id.org/oak/taxon_constraints