A general-purpose mechanism for organizing elements into groups, establishing ownership of elements, and providing unique names for referencing elements.

See also access, dependency, import, model, namespace, subsystem.


A package is a grouping of model elements and diagrams. Every model element that is not part of another model element must be declared within exactly one namespace; the namespace containing the declaration of an element is said to own the element. A package is a general-purpose namespace that can own any kind of model element that is not restricted to a particular kind of element. A package may contain nested packages and ordinary model elements. Usually there is a single root package that owns the entire model ...

Get Unified Modeling Language Reference Manual, The, Second Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.