UMLR — UML: Diagrams as Model Elements

Diagrams as Model Elements
Make diagrams full and equal model elements, tied to the regular model element that the diagram is displaying. Refer to the SysML specification in Annex A.

All diagrams types should have an unique 2-3 character model element type, and also supporting diagram types.

As a regular model element is should be able to support attributes, such as ownership, status, purpose, version (possibly operations also) and dependencies. As a model element, it should be referable by any URL/URI scheme that can reference model elements.