UML22 — Comments owned by Packages

A package can only own packageable elements. That excludes comments. On the other hand the comment definition states: A comment can be owned by any element. That's a contradiction. It's important that packages can own comments. Therefore I propose a change of the package to allow the ownership of comments.

Discussion: It is not quite right to say that “a package can only own packageable elements”. The spec only says that “Only packageable elements can be owned members of a package.” That is, any owned members of the package, considered as a namespace, must be packageable elements – this is because packagedMember subsets the ownedMember derived union and no other property of Package does. However, a namespace (and hence a package) can have owned elements that are not owned members. In fact, all elements inherit the Element::ownedComment property that subsets ownedElement. For a namespace, ownedMember also subsets ownedElement, so the owned elements of a namespace (and hence a package) include both comments and namespace members. However, while a comment can thus owned by a namespace, it cannot be a member of the namespace, since it is not a named element. Disposition: Closed, no change.