Cost Basis at Supplier ship and debit product line

Hi,

Please let me know what is the functionality that can be achieved by using the 'Cost Basis' field at the supplier ship and debit product line level.

I understand that the cost basis is same as a QP formula and in a TM accrual offer, if the discount type is  % , the cost basis field can be used to write a formula as the basis on which the offer discount value can be calculated.

However what is the use of the cost basis field from the SSD perspective? If the SSD is set up with the discount type as 'New Price', can the cost basis be used for writing any formula on the basis of which the unit rebate amount will be calculated?