When defining a service interface, knowledge of the application and how it is used can enable you to make refinements to the new interface. For example, looking at the COBOL Entry Points pane, notice that the retail price field lnk-b-retail is defined as 9(2)V9(2). If you fully expand the tree for addop_details in the Interface Fields pane, you will see that lnk_b_retail has therefore defaulted to BigDecimal. Imagine that you know from your experience with the application that the retail prices are in fact always in whole numbers of dollars, and that lnk_b_retail can therefore be simply an int. We'll change the type of the lnk-b-retail interface field to reflect this.