This class is used to create a cascading submenu within another menu. It references another PopMenu by the UID that is stored in its MenuReference property.

Autodesk.AutoCAD.Customization.ElementBase
    Autodesk.AutoCAD.Customization.VersionableElement
        Autodesk.AutoCAD.Customization.CustomizationElement
            Autodesk.AutoCAD.Customization.PopMenuItemBase
                Autodesk.AutoCAD.Customization.PopMenuRef

Public Class PopMenuRef
Inherits PopMenuItemBase

public class PopMenuRef : PopMenuItemBase;