UML22 — Diagram metaclass shall be introduced and shall be subclass of Element

Diagram metaclass shall be introduced and shall be subclass of Element, because every tool need to add Diagrams into packages (and uses hacks to do that) , Dependencies between diagrams is usable also. Stereotypes for diagrams are also used and even represented in DiagramFrame notation

Discussion: This is definitely outside the scope of an RTF. However, it is also very much against one of the fundamental architectural principles of UML, that the abstract and concrete syntaxes are to be kept distinct. For instance, it should be possible to provide a UML concrete syntax that is completely textual and, hence, has no notion of diagram. Finally, the question of defining concrete syntaxes for MOF-based modeling languages and the issue of how these relate to the models themselves is being addressed by a separate RFP (the “Diagram Definition RFP”). Disposition: Closed, no change