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 a maintainer
element must have a
name
child:
<!ELEMENT maintainer (name)>
<!ELEMENT composer (name)>