4.3.4 Omission of Reference Name for a Contained Object

   When a contained object is defined within its container object, the default language rules require the name of the MOF Reference to identify the containment association involved. However, in practice, there is often only one containment association from the container class to the contained class, and therefore the MOF Reference name can be omitted. When there are two containment associations by which a contained object and its container may be linked, the omission of the reference name is not permitted.