The Relationship Tool works similarly to the Object Tool. Its appearance (Figure 2–3) and functions are similar with the obvious exception that it is used only for viewing and editing specifications of relationship types. Examples of relationship types are Transition in WatchApplication diagrams, or Inheritance in UML Class Diagram.

The fields in the Relationship Tool are the same as the Object Tool. Relationships can have properties and the arrangement of the property dialog can be modified as in the Object Tool. Relationship types can have symbols as well. If no symbol is defined, relationships have no visible component in Diagram Editors, just a red dot at the middle or meeting point of the role lines.

Note that the rules about which objects can be connected by which relationships are not part of the relationship type, but rather are defined by bindings and constraints in the Graph type (see Sections 2.5.4 and 2.5.5).