Unified Modeling Language Reference Manual, The, Second Edition

include

A relationship from a base use case to an inclusion use case, specifying that the behavior defined for the inclusion use case is to be inserted into the behavior defined for the base use case. The base use case can see the inclusion and can depend on the effects of performing the inclusion, but neither the base nor the inclusion may access each other's attributes.

See also extend, use case, use case generalization.

Semantics

The include relationship connects a base use case to an inclusion use case. The inclusion use case in this relationship is not a separate instantiable classifier. Instead, it explicitly describes an additional behavior sequence that is inserted into a use case instance that is executing the base use case. Multiple ...