P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="valList">
<rng:ref name="att.global.attributes"/>
<rng:optional>
 <rng:attribute name="mode" a:defaultValue="add">
  <rng:choice>
   <rng:value>add</rng:value>
   <rng:value>delete</rng:value>
   <rng:value>change</rng:value>
   <rng:value>replace</rng:value>
  </rng:choice>
 </rng:attribute>
</rng:optional>
<rng:optional>
 <rng:attribute name="type" a:defaultValue="open">
  <rng:choice>
   <rng:value>closed</rng:value>
   <rng:value>semi</rng:value>
   <rng:value>open</rng:value>
  </rng:choice>
 </rng:attribute>
</rng:optional>
<rng:oneOrMore>
 <rng:ref name="valItem"/>
</rng:oneOrMore>
</rng:element>

element valList
{
   att.global.attributes,
   attribute mode { "add" | "delete" | "change" | "replace" }?,
   attribute type { "closed" | "semi" | "open" }?,
   valItem+
}