an extensibility mechanism that allows you to create new information about model element s and presentation element s
an extension of the properties of a UML element
a property-value pair that may be defined by the user
a (Tag, Value) pair that permits arbitrary information to be attached to any model element
The explicit definition of a property as a name-value pair. In a tagged value, the name is referred as the tag. Certain tags are predefined in the UML; others may be user defined. Tagged values are one of three extendibility mechanisms in UML. See: constraint, stereotype.