This is the base class of RibbonRowPanel and RibbonFoldPanel. It is mostly for internal use except for providing some common properties between the two panels. Please use RibbonRowPanel and RibbonFoldPanel in your applications.

Autodesk.AutoCAD.Customization.ElementBase
    Autodesk.AutoCAD.Customization.VersionableElement
        Autodesk.AutoCAD.Customization.CustomizationElement
            Autodesk.AutoCAD.Customization.RibbonItem
            Autodesk.AutoCAD.Customization.ICustomizationContainer
                Autodesk.AutoCAD.Customization.AbstractRibbonSubPanel
                    Autodesk.AutoCAD.Customization.RibbonFoldPanel
                    Autodesk.AutoCAD.Customization.RibbonRowPanel

Public abstract Class AbstractRibbonSubPanel
Inherits RibbonItem
Inherits ICustomizationContainer

public abstract class AbstractRibbonSubPanel : RibbonItem, ICustomizationContainer;