Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/eduni/namespaces/1.0/001.xml
<?xml version="1.0"?> <!-- Namespace name test: a perfectly good http URI --> <!DOCTYPE foo [ <!ELEMENT foo ANY> <!ATTLIST foo xmlns CDATA #IMPLIED> ]> <foo xmlns="http://example.org/namespace"/>