To provide a link to the element definition in case the inforamtion is coming from an external file. The link would correpsond to a xlink.  | 
                           
| Complex Types | dx:elementType, dx:valueType | 
| Element | dx:usage | 
<xs:attribute name="href" type="xs:string"> <xs:annotation> <xs:documentation>To provide a link to the element definition in case the inforamtion is coming from an external file. The link would correpsond to a xlink.</xs:documentation> </xs:annotation> </xs:attribute>  |