test/relaxng/tutor1_2.rng

<element name="addressBook" xmlns="http://relaxng.org/ns/structure/1.0">
  <oneOrMore>
    <element name="card">
      <element name="name">
        <text/>
      </element>
      <element name="email">
        <text/>
      </element>
    </element>
  </oneOrMore>
</element>