XMI24 — 5.2 rule 6

5.2 rule 6 defines PackageElement which seems to have no purpose - such an element will never appear in an XMI file (there is nothing in section 6.4 for it).
So this whole rule 6 and sub-rules 6a to 6h should be deleted.

Though a metamodel package defines elements, there is no need for an element for the package itself: there is never the need to exchange an instance of the package ‘UML’ as an XML element for example (as opposed to instances of uml:Model or uml:Package as defined by the UML metamodel). Furthermore there is nothing in section 4.8 covering ‘Package Representation’.

Unlike MOF 1.x, MOF 2 does not support static features : this was one original reason for packageElements at earlier versions of MOF/XMI.