partial xml in atom:content ?

[Eric Scheid]

Is this a valid atom entry?

    <entry>
        [...elided...]
        <summary>a snippet of foo xml</summary>
        <content type="application/foo+xml">
            <foo:thing xmlns:foo="http://xmlns.com/foo/0.1/";>
                <foo:name>King George</foo:name>
            </foo:Person>
        </content>
    </entry>

That is, is a partial xml document valid inside the atom:content element?
What about xml formats whose specs state that there must be a certain root
element (similar to how atom documents must have either <feed> or <entry> as
root elements)?

e.