The property umbel:isAbout is used to assert the relation between a named entity (individual) and a Reference Concept class. umbel:isAbout relates the named entity (individual) to the class through the basis of its subject matter. The relation acknowledges that the scope of the class can not be determined solely by the aggregation or extent of its associated individual entity members, and that the nature of the Reference Concept class may not alone bound or define the individual entity.
This property is therefore used to create a topical assertion between an individual and a Reference Concept.