<fsConstraints>

<fsConstraints> (功能結構限制) 指出完善功能結構的內容限制。 [18.11 Feature System Declaration]
組件iso-fs — Feature Structures
屬性att.global (@xml:id, @n, @xml:lang, @rend, @style, @rendition, @xml:base, @xml:space) (att.global.linking (@corresp, @synch, @sameAs, @copyOf, @next, @prev, @exclude, @select)) (att.global.analytic (@ana)) (att.global.facs (@facs)) (att.global.change (@change))
可包含在於
iso-fs: fsDecl
可包含
iso-fs: bicond cond
宣告

<rng:element name="fsConstraints">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.linking.attributes"/>
 <rng:ref name="att.global.analytic.attributes"/>
 <rng:ref name="att.global.facs.attributes"/>
 <rng:ref name="att.global.change.attributes"/>
 <rng:zeroOrMore>
  <rng:choice>
   <rng:ref name="cond"/>
   <rng:ref name="bicond"/>
  </rng:choice>
 </rng:zeroOrMore>
</rng:element>
element fsConstraints
{
   att.global.attributes,
   att.global.linking.attributes,
   att.global.analytic.attributes,
   att.global.facs.attributes,
   att.global.change.attributes,
   ( cond | bicond )*
}
例子
<fsConstraints>
 <cond>
  <fs>
<!-- ...-->
  </fs>
  <then/>
  <fs>
<!-- ... -->
  </fs>
 </cond>
</fsConstraints>