Return Value
            The name of the field used to define subtypes.
            
| Exception | Description | 
|---|---|
| System.NotSupportedException | The definition does not support this operation (e.g., the table is a shapefile). | 
| ArcGIS.Core.Data.Exceptions.GeodatabaseException | A geodatabase-related exception has occurred. | 
Target Platforms: Windows 11, Windows 10, Windows 8.1