Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/libraries/HaXml/tests/xml-conformance/ibm/invalid/P56/out/ibm56i02.xml
<tokenizer UniqueName="Ac999"> <b attr="Ac999"></b> This is a negative test for validity constraints the value of the attribute with a type ID appears more than once in the XML document </tokenizer>
