For this entry transaction, the parameter is used to defines the value of the discount/charge field.
Hidden:The field does not appear in the entry screen, but a value can be assigned to it via the price search.
Displayed: The value can be assigned to it via the price search and is displayed. It cannot be modified.
Entered: The value can be assigned to it via the price search and is displayed. It can be modified.
The default value assigned to the Discount/Charge fields depends on the result of the price search.