Describes a field of a SemanticType Defines a semantic type. Notes: Granularity of SemanticType is infered from the granularity of the record it derives from. In a record, this granularity is specified by the AppliesTo attribute. This specifies what this record is an attribute of. The options are Global, Dataset, Image, or Region. Describes semantic types that can be derived from custom attributes. Just some human-readable text to serve as documentation.