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.