1<schema xmlns="http://www.ascc.net/xml/schematron" > 2 <pattern name="Test attribute"> 3 <rule context="CCC"> 4 <report test="parent::BBB and not(@id)">Attribute id is missing</report> 5 <report test="not(parent::BBB) and @id">Attribute id is used in wrong context</report> 6 </rule> 7 </pattern> 8</schema> 9 10