How do I use System Fields on a BI Publisher report?

I have a requirement to create a new report in BI Publisher for our Siebel 8.1 environment. I am having a problem getting the "Updated" field to display in the report. One of the required fields is the date of the last update on the Service Request. This is a system field. The applets refer to it simply as "Updated". I have added that field to the appropriate Integration Object for my report and regenerated the Sample XML, but the field does not appear in the XML file. I seem to remember that BIP cannot use these System fields in