Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/xmltest/valid/sa/out/076.xml
<!DOCTYPE doc [ <!NOTATION n1 SYSTEM 'http://www.w3.org/'> <!NOTATION n2 SYSTEM 'http://www.w3.org/'> ]> <doc></doc>