xmlns="http://relaxng.org/ns/structure/1.0">

  <zeroOrMore>

    <element name="card" ns="http://www.example.com">

      <element name="name" ns="http://www.example.com">

        <text/>

      </element>

      <element name="email" ns="http://www.example.com">

        <text/>

      </element>

    </element>

  </zeroOrMore>

</element>