DesignerActionTextItem Represents a string on the smart tag panel
DesignerActionHeaderItem Represents a bolded string on the smart tag panel
DesignerActionMethodItem Represents a command link on the smart tag panel. Each method item is backed by a method in a DesignerActionList.
DesignerActionPropertyItem Represents a property entry on the smart tag panel. Each property item is backed by a property on a DesignerActionList. Boolean properties are represented by a check box.