P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="u">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.timed.attributes"/>
 <rng:ref name="att.duration.w3c.attributes"/>
 <rng:ref name="att.declaring.attributes"/>
 <rng:ref name="att.ascribed.attributes"/>
 <rng:optional>
  <rng:attribute name="trans" defaultValue="smooth">
   <rng:choice>
    <rng:value>smooth</rng:value>
    <rng:value>latching</rng:value>
    <rng:value>overlap</rng:value>
    <rng:value>pause</rng:value>
   </rng:choice>
  </rng:attribute>
 </rng:optional>
 <rng:zeroOrMore>
  <rng:choice>
   <rng:text/>
   <rng:ref name="model.gLike"/>
   <rng:ref name="model.phrase"/>
   <rng:ref name="model.global"/>
  </rng:choice>
 </rng:zeroOrMore>
</rng:element>

element u
{
   att.global.attributes,
   att.timed.attributes,
   att.duration.w3c.attributes,
   att.declaring.attributes,
   att.ascribed.attributes,
   attribute trans { "smooth" | "latching" | "overlap" | "pause" }?,
   ( text | model.gLike | model.phrase | model.global )*
}