All of the UML diagram link elements share common context menu commands. To use the context menu for a link, simply right click on the link in the Diagram view. To view the common context menu commands, see Common Link Context Commands.
On a class or package diagram the association, composition, and aggregation links share the common context menu commands. In addition to the common commands, this context menu offers the Apply Pattern command:
Selecting this command launches the Apply Pattern dialog displaying the available patterns. Select a pattern from the Patterns list to apply to the link.
Tip: There are many patterns to choose from. For example, use Apply Pattern to designate a link as an association array list or hashtable.