<billing.information person.href='person.1.xml'> 
  <credit.card id='c1' type='visa' number='1234123412341234' expires.on='20000601'>
    <name>Bill Jones</name> 
      <us.address object.id='object:account3:0007'>
        <street>10 Pluto Terrace</street> 
        <city>Chicago</city> 
        <state>IL</state>
        <zip main='60601' sub='6000'/> 
      </us.address> 
  </credit.card> 
</billing.information>