TEI: Guidelines for Electronic Text Encoding and Interchange

<taxonomy xml:id="tax.b">
<bibl>Brown Corpus</bibl>
<category xml:id="tax.b.a">
<catDesc>Press Reportage</catDesc>
<category xml:id="tax.b.a1">
<catDesc>Daily</catDesc>
</category>
<category xml:id="tax.b.a2">
<catDesc>Sunday</catDesc>
</category>
<category xml:id="tax.b.a3">
<catDesc>National</catDesc>
</category>
<category xml:id="tax.b.a4">
<catDesc>Provincial</catDesc>
</category>
<category xml:id="tax.b.a5">
<catDesc>Political</catDesc>
</category>
<category xml:id="tax.b.a6">
<catDesc>Sports</catDesc>
</category>
</category>
<category xml:id="tax.b.d">
<catDesc>Religion</catDesc>
<category xml:id="tax.b.d1">
<catDesc>Books</catDesc>
</category>
<category xml:id="tax.b.d2">
<catDesc>Periodicals and tracts</catDesc>
</category>
</category>
</taxonomy>

<taxonomy>
<category xml:id="literature">
<catDesc>Literature</catDesc>
<category xml:id="poetry">
<catDesc>Poetry</catDesc>
<category xml:id="sonnet">
<catDesc>Sonnet</catDesc>
<category xml:id="shakesSonnet">
<catDesc>Shakespearean Sonnet</catDesc>
</category>
<category xml:id="petraSonnet">
<catDesc>Petrarchan Sonnet</catDesc>
</category>
</category>
<category xml:id="haiku">
<catDesc>Haiku</catDesc>
</category>
</category>
<category xml:id="drama">
<catDesc>Drama</catDesc>
</category>
</category>
<category xml:id="meter">
<catDesc>Metrical Categories</catDesc>
<category xml:id="feet">
<catDesc>Metrical Feet</catDesc>
<category xml:id="iambic">
<catDesc>Iambic</catDesc>
</category>
<category xml:id="trochaic">
<catDesc>trochaic</catDesc>
</category>
</category>
<category xml:id="feetNumber">
<catDesc>Number of feet</catDesc>
<category xml:id="pentameter">
<catDesc>>Pentameter</catDesc>
</category>
<category xml:id="tetrameter">
<catDesc>>Tetrameter</catDesc>
</category>
</category>
</category>
</taxonomy>
<!-- elsewhere in document -->
<lg ana="#shakesSonnet #iambic #pentameter">
<l>Shall I compare thee to a summer's day</l>
<!-- ... -->
</lg>

XML syntaxCompact syntax

<rng:element name="taxonomy">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.analytic.attributes"/>
 <rng:ref name="att.global.change.attributes"/>
 <rng:ref name="att.global.facs.attributes"/>
 <rng:ref name="att.global.linking.attributes"/>
 <rng:ref name="att.global.rendition.attributes"/>
 <rng:ref name="att.global.responsibility.attributes"/>
 <rng:ref name="att.global.source.attributes"/>
 <rng:ref name="att.datcat.attributes"/>
 <rng:choice>
 <rng:choice>
  <rng:oneOrMore>
  <rng:choice>
   <rng:ref name="category"/>
   <rng:ref name="taxonomy"/>
  </rng:choice>
  </rng:oneOrMore>
  <rng:group>
  <rng:oneOrMore>
   <rng:choice>
   <rng:ref name="model.descLike"/>
   <rng:ref name="equiv"/>
   <rng:ref name="gloss"/>
   </rng:choice>
  </rng:oneOrMore>
  <rng:zeroOrMore>
   <rng:choice>
   <rng:ref name="category"/>
   <rng:ref name="taxonomy"/>
   </rng:choice>
  </rng:zeroOrMore>
  </rng:group>
 </rng:choice>
 <rng:group>
  <rng:ref name="model.biblLike"/>
  <rng:zeroOrMore>
  <rng:choice>
   <rng:ref name="category"/>
   <rng:ref name="taxonomy"/>
  </rng:choice>
  </rng:zeroOrMore>
 </rng:group>
 </rng:choice>
</rng:element>

element taxonomy
{
 att.global.attributes,
 att.global.analytic.attributes,
 att.global.change.attributes,
 att.global.facs.attributes,
 att.global.linking.attributes,
 att.global.rendition.attributes,
 att.global.responsibility.attributes,
 att.global.source.attributes,
 att.datcat.attributes,
 (
 (
 ( category | taxonomy )+
 | ( ( model.descLike | equiv | gloss )+, ( category | taxonomy )* )
 )
 | ( model.biblLike, ( category | taxonomy )* )
 )
}