<?xml version="1.0"?>

<!DOCTYPE foo [

<!ELEMENT foo (bar)>
<!ATTLIST foo id CDATA #IMPLIED>
<!ELEMENT bar (#PCDATA|cheese)*>
<!ATTLIST bar id ID #REQUIRED>
<!ELEMENT cheese (#PCDATA)>
<!ATTLIST cheese kind ID #IMPLIED>
]>

<foo id="foobar">
  <bar id="fb1">
    baz
    <cheese kind="edam">gouda</cheese>
    baz
    <cheese kind="gouda">cheddar</cheese>
    baz
  </bar>
</foo>