A common requirement is the mapping of strings found in the source document to different strings to be used in the target document – for example the mapping of codes to names, or a translation between different code systems. While it would be possible to describe a value mapping by filling an @atom attribute with a switch expression, mappings are much easier to define and maintain when specified by dedicated mapping tables. Example:

   <z:valueMap name="OperationalStatus">
     <z:entry from="true" to="Open"/>
     <z:entry from="false" to="Closed"/>
     <z:entry to="Closed"/>
   </z:valueMap>

The document model of a SNAT document contains a prolog section where such maps can be placed. An @atom item can invoke a particular mapping use the syntax %map-$mapName, where $mapName must be replaced by the name of the appropriate value map (e.g. atom="%map-OperationalStatus").