P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="langKnown">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.datable.w3c.attributes"/>
 <rng:ref name="att.datable.iso.attributes"/>
 <rng:ref name="att.editLike.attributes"/>
 <rng:attribute name="tag">
  <rng:ref name="data.language"/>
 </rng:attribute>
 <rng:optional>
  <rng:attribute name="level">
   <rng:ref name="data.word"/>
  </rng:attribute>
 </rng:optional>
 <rng:ref name="macro.phraseSeq.limited"/>
</rng:element>

element langKnown
{
   att.global.attributes,
   att.datable.w3c.attributes,
   att.datable.iso.attributes,
   att.editLike.attributes,
   attribute tag { data.language },
   attribute level { data.word }?,
   macro.phraseSeq.limited
}