Can Collada be a container for U3D

In one of the topics the Collada format is described as being a superset of U3D.
Does this mean that Collada acts as a kind of container for a U3D-file ?

Our software supports the U3D-export (amongst others);
One of our partners allows Collada-import.
If we could package our U3D-file as a Collada container, maybe add some additional default entities (which we don’t need, but may be required by Collada) we could link both software in a better way …

Hope someone can shed a light on this

best regards

The COLLADA feature set is a superset of U3D. Other then that they are separate specifications and you would need to translate content from one to the other, using a tool like Polytrans for example.