expression.AllowAdditions
expression Required. An expression that returns a GroupLevel or PivotView object.
Remarks
When this property is set to True, an asterisk (*) will be displayed in a blank row in the detail area. Any new records added to the detail area of a PivotTable list are also added to the source database.
You cannot add records to the detail area of the PivotTable list if the source recordset does not allow insertions.
Example
This example allows the user to add new records to the detail area of PivotTable1.
PivotTable1.ActiveView.AllowAdditions = True