test/valid/ns2.xml

<?xml version="1.0"?>
<!DOCTYPE a:outer [

<!ELEMENT a:outer (a:inner)>
<!ATTLIST a:outer xmlns:a CDATA #FIXED 'urn:namespace'>

<!ELEMENT a:inner EMPTY>
<!ATTLIST a:inner xmlns:a CDATA #FIXED 'urn:namespace'>
<!ATTLIST a:inner attr CDATA #FIXED 'yes'>
]>

<a:outer xmlns:a="urn:namespace">
  <a:inner />
</a:outer>