Child Elements

You only have to declare the immediate children

   <maintainer email="elharo@metalab.unc.edu" 
              url="http://www.macfaq.com/personal.html">
    <name>
      <first_name>Elliotte</first_name> 
      <middle_name>Rusty</middle_name> 
      <last_name>Harold</last_name>
    </name>
  </maintainer>

  <composer id="c1">
    <name>
      <first_name>Julie</first_name> 
      <middle_name></middle_name> 
      <last_name>Mandel</last_name>
    </name>
  </composer> 

• To declare that an element must have exactly one name child:

<!ELEMENT maintainer (name)>
<!ELEMENT composer (name)>