A rectangle with three sections for name, attributes, and operations. The attribute section is empty and the operation section is limited to the publicly available methods of the Interface. An alternate representation is a circle and a unique name. Therefore, collaborations have both structural as well as behavioral meanings. A single class might participate in more than one Collaboration.
Collaborations represent the implementation of patterns that make up the system.
An ellipse with dashed lines usually labeled with the Collaboration name. Use Cases are used to structure the behavioral elements of the system. The realization of a Use Case is a Collaboration. An ellipse with solid lines, usually only including the Use Case name as a label. However, their uses are unique enough to require special treatment.