++++ Agriculture - Common organization of the markets - Milk and milk products - Additional levy on milk - Determination of the reference quantities exempt from the levy - Producer selling directly for consumption - Basis of calculation - Quantities marketed directly during the reference year and produced by the farmer' s own herd ( Regulation No 804/68 of the Council, Art . 5c, and Council Regulation No 857/84, Art . 6(1 ) )