In an Unified Modeling Language (UML) use case diagram, an include dependency is a generalization relationship that describes the inclusion of the behavior described by another use case. A UML use case can include more than one use cases and it can be included in multiple use cases.
An include dependency is represented by a dashed arrow from the base use case to the inclusion use case marked with the include keyword. The base use case is responsible for identifying where in its behavior sequence or at which step to include the inclusion use case. This identification is not done in the UML diagram, but rather in the textual description of the base use case.