Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/ibm/xml-1.1/not-wf/P05/ibm05n04.xml
<?xml version="1.1" encoding="UTF-8"?> <!DOCTYPE root [ <!ELEMENT root ANY> <!ELEMENT ‿BadName EMPTY> ]> <!-- BadName containing char 0x203F; --> <root> <‿BadName/> </root>