Before-image data is serialized in a proprietary OpenEdge datasetChanges document. The WSDL represents the parameter as arbitrary complex data with an <any> element. All SOAP formats represent this data as arbitrary complex data with XML Schema attributes that identify it as an OpenEdge datasetChanges document.

An ABL-based client can map the <any> element to a ProDataSet parameter and parse the OpenEdge datasetChanges document into a ProDataSet and its before-image data. For more information on how ABL handles before-image data in XML, see the chapter on reading and writing XML data from ProDataSets in OpenEdge Development: Working with XML. Non-ABL clients map the <any> element to an XML document that the client developer needs to parse with an XML API.