Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/ibm/valid/P56/out/ibm56v10.xml
<test> <nametokens thistoken="x:lang y:country"></nametokens> In an attribute declaration, values of type NMTOKENS match the Nmtokens production </test>