Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/eduni/xml-1.1/049.xml
<?xml version="1.1"?> <!-- has an LSEP character in element content whitespace; well-formed in both XML 1.0 and 1.1, but valid only in 1.1 --> <!DOCTYPE foo [ <!ELEMENT foo (foo*)> ]> <foo> </foo>