<foo xmlns:petal="http://purl.org/petal/1.0/willBeReplaced"
     xmlns:petal-meta="http://purl.org/petal/1.0/"
     petal-meta:attributes="xmlns:petal string:http://purl.org/petal/1.0/">
        <bar baz="default" 
             buzz="default"
             quxx="default"
             petal:attributes="baz replace; buzz replace; quxx replace"
             petal-meta:attributes
                 ="petal:attributes string:baz ${baz_meta}\; buzz ${buzz_meta}\; quxx ${quxx_meta}" />
        <bat petal-meta:content="string:Content\;"></bat>
        <bat petal-meta:replace="string:Replace\;"></bat>
</foo>