1  <?xml version="1.0"?>
 2  <!DOCTYPE a:outer [
 3  <!ELEMENT a:outer (a:inner)>
 4  <!ATTLIST a:outer xmlns:a CDATA #FIXED "urn:namespace">
 5  <!ELEMENT a:inner EMPTY>
 6  <!ATTLIST a:inner xmlns:a CDATA #FIXED "urn:namespace">
 7  <!ATTLIST a:inner attr CDATA #FIXED "yes">
 8  ]>
 9  <a:outer xmlns:a="urn:namespace">
10    <a:inner/>
11  </a:outer>