1./test/valid/xlink.xml:450: element termdef: validity error : ID dt-arc already defined 2 <p><termdef id="dt-arc" term="Arc">An <term>arc</term> is contained within an e 3 ^ 4./test/valid/xlink.xml:199: element termref: validity error : IDREF attribute def references an unknown ID "dt-xlg" 5