If you are going to use GroupWise Events, you should be familiar with XML and SOAP concepts, including those described in the following links:
XML Schema Specifications:
http://www.w3.org/TR/xmlschema-0/
http://www.w3.org/TR/xmlschema-1/
http://www.w3.org/TR/xmlschema-2/
SOAP:
http://www.w3.org/TR/soap12-part0/
http://www.w3.org/TR/soap12-part1/
http://www.w3.org/TR/soap12-part2/