libopc/third_party/libxml2-2.7.7/test/relaxng/tutor3_1.rng

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