In UML modeling, when you
draw use-case diagrams, you communicate the essence of the system
or application without exposing unnecessary details. It's generally
good practice to hide the complexity of the system, but there are
times when you might need to expose details. You can depict these
details in their own use cases and connect them to base use cases,
which enables you to reveal information that would otherwise be hidden.
Creating an extension point for a use case
In UML modeling, you can
create extension points for the base use case. These extension points
identify where the behavior of an extension use case can be inserted
into the base use case.