The HasDataTypeRefinement is a concrete ReferenceType and can be used directly. It is a subtype of HasChild.
The semantic of this ReferenceType is to link from a DataType to a DataTypeRefinement Object that defines the allowed refinements of instances of a DataType.
The SourceNode of References of this type shall be a DataType.
The TargetNode of this ReferenceType shall be a DataTypeRefinement Object or a subtype.