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