Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/ibm/valid/P58/out/ibm58v01.xml
<!DOCTYPE test [ <!NOTATION that SYSTEM 'beta'> <!NOTATION this SYSTEM 'alpha'> ]> <test> This is a positive test with different patterns for NOTATION </test>