Markup % (aka Negative Discount) on Sales order line

The system currently allows for a product discount to be setup and is called MARKUP % discount. The system’s setting allows for a MARKUP % and further allows for the discount % to be updated (rather than the sales price). But on the sales order the system doesn’t accept a negative value in the discount field.

When the discount is applied on a sales order line, the discount % column correctly shows -12% for example (to indicate a markup on the sales price) but when the sales order is approved then the system shows an error message that says DISCOUNT % HAS TO BE BETWEEN 0 AND 100.

How can the system allow for a Markup % in the settings page but when it is applied on the sales order line then the system doesn't allow a negative discount value?

Per discussion with the Tech guys, they have agreed to implement this correction if i raise a feature request.