<?xml version="1.0" encoding="UTF-8"?>

<!ELEMENT outer:song (outer:verse*)>
<!ATTLIST song 
	  xmlns:outer CDATA #FIXED "http://outer.com/"
	  xmlns:inner CDATA #FIXED "http://inner.com/">

<!ELEMENT outer:verse (inner:line*)>
<!ELEMENT inner:line (#PCDATA)>