Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/ibm/not-wf/P18/ibm18n01.xml
<?xml version="1.0"?> <!DOCTYPE student [ <!ELEMENT student (#PCDATA)> ]> <!-- testing invalid CDSect with missing CDStart --> <student>My Name is SnowMan. This is <normal> text]]></student>