=+1. Revenue recognition, when the right of return exists, was standardized in 1981 by SEAS No. 48. Prior to this, SOP 75-1 provided guidance but was not mandatory (which is why the FASB has brought various SO/'s into the accounting standards themselves). As a result, three methods were widely used to account for this type of transaction: (1) no sale recognized until the product was unconditionally accepted,