An External Report places an absolute link into the report list that can point to any valid web page. It allows, among other things, linking to another reporting engine or service. The Data tag contains the full external URL and must start with http or https.
This is an example report that displays the IBM home page:
<BESWebReport> <Name>Example External Report</Name> <Description> Home Page </Description> <Type>ExternalReport</Type> <Category>External Report</Category> <Source>IBM</Source> <Data> http://www.ibm.com </Data> </BESWebReport>