References Element

A feature mapping rule may also contain an optional <references> element. This element specifies reference-sets that hold name/value pairs that may be accessed via <refexpr> expression elements. A detailed description for the <references> element and its content may be found in the Reference Mapping Rules section.

In a feature mapping rule the <references> element should appear before the <feature-type> element, for example:

<feature-map>
	<mapping match="...">
		...
		<references>...</references>
		<feature-type>...</feature-type>
		...
	</mapping>
</feature-map>