Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/sun/not-wf/attlist11.xml
<!DOCTYPE root [ <!ELEMENT root ANY> <!ATTLIST root att1 CDATA #IMPLIED> <!ATTLIST root att2 CDATA #IMPLIED> ]> <root att1="value1"att2="value2"/> <!-- whitespace required between attributes -->
