Extended notification: Grouping messages

Hi,

I would like to have the text of several workitems in one extended notification like described here: Extended Notifications for SAP Business Workflow - Claim - SAP Library

In the category I put "Grouping with Other Categories Permitted" but there is only the mail coming with the text that there are woritems in my business workplace. Does someone knows a good tutorial about displaying workitem texts in the mail?

Regards, Vanessa