An Extension is used to indicate that the Properties of a Metaclass are extended through a Stereotype, and provides the flexibility to add (and later remove) stereotypes to a Class.
An Extension is a kind of Association. One end of the Extension is an ordinary Property that ties the Extension to a Class. The other end is an ExtensionEnd tying the Extension to a stereotype that extends the Class.
You can specify an Extension by changing its property values in the Extension Specification window. Each property is described in the description area on this window.
You can format the Extension symbol properties in the Symbol Properties dialog.
