There are several different ways to give discounts. There are several options you can set to help control the way discounts are given.

First, you can define a sales category as discountable or not discountable. Maybe you allow discounts on liquor and wine but not on soda and beer.

Second, most retailers don't allow discounts on items that are on sale.

Third, you probably don't want to sell an item below cost.

Fourth, you might not allow a discount on the case price. For example, your case price already reflects a discounted price so you don't want any further discounts given on the case.

Fifth, the discount key can be passworded. If the cashier hits the discount key, you can set up security so a manager has to enter his ID and password to allow the discount. We call this a manager's override. You can set up security even further and require the manager to respond to a question that asks, AUTHORIZE FOR ENTIRE SALE? Maybe you only want the cashier to discount one item in the sale.

Once you have discounts set up to match your policies, the cashier doesn't have to know what's discountable, what isn't discountable. All he has to do is scan the items. The register keeps track of those items entitled to a discount. As a matter of fact, take a look at the D column on the sales screen. If an item is entitled to a discount, a Y is displayed. If not, an N is displayed