An Element that stores a user-defined parameter. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 16.0.0.0 (16.0.0.0) 
  Since:  2016 
Syntax
Remarks
 Revit supports both built-in and user-defined parameters. Built-in parameters ship with the application, and they are not stored in Revit documents. User-defined parameters are dynamically created, and they are stored in the documents that use them, wrapped in ParameterElement objects. Different subclasses of ParemeterElement represent different kinds of user-defined parameters. 
 Inheritance Hierarchy
  System Object  
Autodesk.Revit.DB Element
Autodesk.Revit.DB ParameterElement
Autodesk.Revit.DB GlobalParameter
Autodesk.Revit.DB SharedParameterElement
 
 Autodesk.Revit.DB Element
Autodesk.Revit.DB ParameterElement
Autodesk.Revit.DB GlobalParameter
Autodesk.Revit.DB SharedParameterElement