A parameter in structural families which allows for family type identification. This will be used for data mapping during model exchange with another program, namely Advance Steel. 
   Namespace:   Autodesk.Revit.DB.Structure.StructuralSections  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 16.0.0.0 (16.0.0.0) 
  Since:  2015 
Syntax
Exceptions
| Exception | Condition | 
|---|---|
| Autodesk.Revit.Exceptions ArgumentNullException | When setting this property: A non-optional argument was NULL |