@namespace("eu.dnetlib.iis.referenceextraction.researchinitiative.schemas")
protocol IIS{

    record DocumentToConceptId {
//      document ID, foreign key: DocumentText.id
        string documentId;
        string conceptId;
//		Find more details on `confidenceLevel` constraints in eu/dnetlib/iis/README.markdown file.
        union { null , float } confidenceLevel = null;
    }
}