In UML models, you can add template parameters to classes
to create template classes, and to collaborations to create patterns.
A template parameter is a placeholder that another
model element must fill when a new model element is generated from the
template. You can use template parameters to create general definitions
of particular types of template. For example, when you add template
parameters to a class, it becomes a template class, which is sometimes
called a parameterized class. If you use a template class as a general
pattern, you can create a group of classes that use template parameters
to define more specific behavior.
You must have a model that contains
at least one class or collaboration open in the Modeling perspective.
To add a template parameter to a class or collaboration,
in the Model Explorer view, right-click a class
or collaboration; then click .