On the SalesData sheet the Referral % field calculates the referral percentage from column R, selling fees / column M, product sales. The FP Ref % is the referral percentage calculated from the FeePreview data. This is simply a reference to see if the referral percentages are different between the two. This will only happen when the item was moved to a product group where the referral fees are different. Keep in mind that the percentage can be higher than the product group referral percentage when there is a minimum referral fee (usually $1). Ref. Dif? will say “Yes” when the difference between the two if greater than 5%. This result is not reported on the Order Summary report.