Like template reports, custom reports use the Rule Tree Editor to determine what label templates should be used in your report. A default set of rules is automatically included, so you only need to change the default rules if you want to load some sort of custom label template.
To work with these rules,
Right-click on the editing area (the Page object) in the Custom Report Editor (File | Reporting | New | Custom Report).
Select Properties from the small popup menu. The Properties dialog box appears.
Click on Rule... in the Rule Tree Editor property. The Rule Tree Editor appears
Modify the rules as desired.
For information on accessing and using the Rule Tree Editor, see "About the Rule Tree Editor".