Show opaque background behind the text during editing. 
   Namespace:   Autodesk.Revit.UI  
  Assembly:   RevitAPIUI  (in RevitAPIUI.dll) Version: 17.0.0.0 (17.0.1090.0) 
  Since:  2017 
Syntax
Remarks
 If false, the background will be opaque or not depending on the edited text note's type Background setting. If true, the background behind the text will always be opaque during editing.