<rng:ref name="data.pointer"/>
data.pointer
<rng:element name="classCode"><rng:ref name="att.global.attributes"/><rng:attribute name="scheme"> <rng:ref name="data.pointer"/></rng:attribute><rng:ref name="macro.phraseSeq.limited"/></rng:element>
element classCode{ att.global.attributes, attribute scheme { data.pointer }, macro.phraseSeq.limited}