A stereotype is used to extend meta classes, and the underlying metamodel, by introducing new properties to the meta class. Similar to a class, a stereotype may have properties which are referred to as tag definitions. When a stereotype is applied to a model element, the values of the properties may be referred to as tagged values.

A stereotype can extend any classifier: Classes, Components, Attributes, Use Cases, States, Transitions, Activities, Dependencies, and so on.

A stereotype can be created as separate model element and drawn on a diagram.