UModel supports the ball and socket notation of UML. Classes that require an interface display a "socket" and the interface name, while classes that implement an interface display the "ball".
In the shots shown above, Class2 realizes Interface1, which is used by classes 1, 3, and 4. The usage icons were used to create the usage relationship between the classes and the interface.
To switch between the standard and ball-and-socket view:
•Click the Toggle Interface notation icon at the base of the interface element.