<catRef>

<catRef> (category reference) specifies one or more defined categories within some taxonomy or text typology. 2.4.3 The Text Classification
Module header — 2 The TEI Header
In addition to global attributes att.pointing (@target, @evaluate)
scheme identifies the classification scheme within which the set of categories concerned is defined
Status Optional
Datatype 

<rng:ref name="data.pointer"/>
data.pointer
Values May supply the identifier of the associated taxonomy element.
Used by
textClass
May contain Empty element
Declaration 

<rng:element name="catRef">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.pointing.attributes"/>
 <rng:optional>
  <rng:attribute name="scheme">
   <rng:ref name="data.pointer"/>
  </rng:attribute>
 </rng:optional>
 <rng:empty/>
</rng:element>
element catRef
{
   att.global.attributes,
   att.pointing.attributes,
   attribute scheme { data.pointer }?,
   empty
}
Example
<catRef target="#news #prov #sales2"/>
<!-- elsewhere -->
<taxonomy>
 <category xml:id="news">
  <catDesc>Newspapers</catDesc>
 </category>
 <category xml:id="prov">
  <catDesc>Provincial</catDesc>
 </category>
 <category xml:id="sales2">
  <catDesc>Low to average annual sales</catDesc>
 </category>
</taxonomy>
Note
The scheme attribute need be supplied only if more than one taxonomy has been declared