This element is used in the <composite:implementation> section. Any child components and/or template text within the composite component tag in the using page will be re-parented into the composite component at the point indicated by this tag's placement within the <composite:implementation> section. The normal use-case for this element is to have exactly one occurrence within the <composite:implementation> section. Inserting multiple occurrences may cause duplicate id errors. The results are undefined if there are multiple occurrences of this element in the <composite:implementation> section. The results are undefined if there are child components and/or template text in the composite component tag in the using page, but there is no occurrence of this element in the <composite:implementation> section.