Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/ibm/not-wf/P72/ibm72n05.xml
<!DOCTYPE root [ <!ELEMENT root (#PCDATA)> <!ATTLIST root att CDATA #IMPLIED> <!--* wrong order *--> <!ENTITY % "<!-- comments -->" paaa> %paaa; ]> <root/>