<?xml version=“1.0”?> <element name=“foo”

       xmlns="http://relaxng.org/ns/structure/1.0"
       xmlns:a="http://relaxng.org/ns/annotation/1.0"
       xmlns:ex1="http://www.example.com/n1"
       xmlns:ex2="http://www.example.com/n2">
<a:documentation>A foo element.</a:documentation>
<element name="ex1:bar1">
  <empty/>
</element>
<element name="ex2:bar2">
  <empty/>
</element>

</element>