1  <element name="ab:addressBook" xmlns:ab="http://www.example.com/addressBook"
 2                                 xmlns:a="http://www.example.com/address"
 3           xmlns="http://relaxng.org/ns/structure/1.0">
 4    <zeroOrMore>
 5      <element name="ab:card">
 6        <element name="a:name">
 7          <text/>
 8        </element>
 9        <element name="a:email">
10          <text/>
11        </element>
12      </element>
13    </zeroOrMore>
14  </element>