This image shows the Data Source tab in the Layout Editor. Under the Data Ds folder is a Sections folder, with a System subfolder. There is a Columnmasks folder under the Systems folder. There are four mask columns shown in the Columnmasks folder: Line Number Mask, Quantity Ordered Mask, Unit Price Mask, and Foreign Unit Price Mask. There is also a Grid0 1 folder under the System folder. The Rowset folder is a subfolder of the Grid0 1 folder. Extended Price Mask is a row mask in the Rowset folder.