Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/eduni/errata-2e/E2b.xml
<!DOCTYPE foo [ <!ELEMENT foo ANY> <!NOTATION one SYSTEM "file:///usr/bin/awk"> <!ATTLIST foo bar NOTATION (one|one) #IMPLIED> ]> <foo/>
