How to add 2D CAD detail inside Revit Window family so you can show it in the project on the callout views or sections.
Go to edit family mode of a window (or different object) and create a section view.
Insert a 2D detail component by going to Insert -> Load a family
Go to Section View and place the 2D CAD component. On the video (I dragged and dropped the family from the project browser, the other method would be to select Annotate->Detail Component)
Remember to check visibility settings. The best method would be to make it visible in the section views on the highest level of detail.