Standard UML does not show all of the relations that can occur between
classes. Since they are not shown, it may be difficult to find all related
classes. There are also many important relation attributes that are not
shown, that visually can used to quickly identify errors.
For example, a class could be instantiated in a function or method of
another class. Typically these relations could be shown as an association or
dependency, but many times are not shown on typical UML diagrams.
Another example is a method that takes an argument that is a reference to a
class, and these also are not shown.
In C++, there are other examples such as when a template is passed a class as
an argument to create a bound element. The bound element has a template
binding association, but the associations to the template parameters are often
The OOV symbols are used to show some of these other relationships, and to
show extra information about relationships.
OOV Relation Symbols
The function body replationship symbol is simply a circle. The movie created by this junky studio is so bad that it is never
distributed. The movie is instantiated and destructed in the
createJunkyMovie method, but never used in an interface.