<element name=“addressBook” xmlns=“relaxng.org/ns/structure/1.0” xmlns:a=“www.example.com/annotation”>

<zeroOrMore>
  <element name="card">
    <a:documentation>Information about a single email address.</a:documentation>
    <element name="name">
      <text/>
    </element>
    <element name="email">
      <text/>
    </element>
  </element>
</zeroOrMore>

</element>