This class contains the panel definition for the panels. It contains the ribbon items of the panel. Multiple tabs can reference a single panel.

Autodesk.AutoCAD.Customization.ElementBase
    Autodesk.AutoCAD.Customization.VersionableElement
        Autodesk.AutoCAD.Customization.CustomizationElement
            Autodesk.AutoCAD.Customization.RibbonItem
            Autodesk.AutoCAD.Customization.ICustomizationContainer
                Autodesk.AutoCAD.Customization.RibbonPanelSource

Public Class RibbonPanelSource
Inherits RibbonItem
Inherits ICustomizationContainer

public class RibbonPanelSource : RibbonItem, ICustomizationContainer;