 must reside within the top level XHTML file for the given
            viewId<span class="changed_modified_2_0_rev_a">, or in a
            template client, but</span> not in a template. The
            implementation must insure that the direct child of the
            facet is a <code>UIPanel</code>, even if there
            is only one child of the facet. The implementation must set
            the id of the <code>UIPanel</code> to be the
            value of the
            <code>UIViewRoot.METADATA_FA