Example: Multiple <ditavalref> elements in a reference to a map
Using multiple instances of the <ditavalref> element in a
         reference to a map is equivalent to referencing that map multiple times, with each
         reference
         nesting one of the <ditavalref> elements.
      
      In the following example, other.ditamap is referenced by a root map.
               The <ditavalref> elements provide conflicting sets of filter
               conditions.
            
Map fragment
<topicref href="parent.dita">
  <topicref href="other.ditamap" format="ditamap">
    <ditavalref href="audienceA.ditaval"/>
    <ditavalref href="audienceB.ditaval"/>
    <ditavalref href="audienceC.ditaval"/>
  </topicref>
</topicref>This markup is functionally equivalent to referencing other.ditamap
               three times, with each reference including a single <ditavalref>
               elements. The fragment could be rewritten as:
            
Map fragment
<topicref href="parent.dita">
  <topicref href="other.ditamap" format="ditamap">
    <ditavalref href="audienceA.ditaval"/>
  </topicref>
  <topicref href="other.ditamap" format="ditamap">
    <ditavalref href="audienceB.ditaval"/>
  </topicref>
  <topicref href="other.ditamap" format="ditamap">
    <ditavalref href="audienceC.ditaval"/>
  </topicref>
</topicref>