Explicit commands or simply indicate the DNAME target?
<dnameDeleg:target>foo.bar.example</dnameDeleg:target>
(as in draft -00) or:
<dnameDeleg:update>
<dnameDeleg:set>foo.bar.example</dnameDeleg:set>
</dnameDeleg:update>
<dnameDeleg:target>foo.bar.example</dnameDeleg:target>
(as in draft -00) or:
<dnameDeleg:update>
<dnameDeleg:set>foo.bar.example</dnameDeleg:set>
</dnameDeleg:update>