Unified Modeling Language Reference Manual, The, Second Edition

extension point

A named marker that identifies a location or set of locations within the behavioral sequence for a use case, at which additional behavior can be inserted. An extension point declaration opens up the use case to the possibility of extension. An insertion segment is a behavior sequence in an extension use case (a use case related to a base use case by an extend relationship). The extend relationship contains a list of extension point names that indicate where the insertion segments from the extension use case insert their behavior.

See also extend, use case.

Semantics

An extension point has a name. It references a set of one or more locations within a use case behavior sequence. The concept of location is not defined within UML, ...