The Amount Type window lets you to determine how the discount amount is calculated.
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Percentage - the discount amount is a percentage of the eligible charges.
Constant Amount - the discount is a fixed amount. This option is not available if the Discount Type is Charge AND the contributing and eligible factors are different. This is the only option that is available Discount Type is Reward Points.
Per Occurrence - the discount amount is a charge for every instance of metered usage. This option is only available if the Discount Type is Charge.
Note
The Percentage amount type cannot be used for Peak Value calculations.