Class rules state the minimum cloth weight of the main is 6.25 oz. Is this minimum weight the weight of the cloth only, or the weight of the cloth inclusive of (for example, in North terms) a high molecular weight urethane "OLY" coating. In other words, do the class rules allow the use of a sail cloth under the 6.25 minimum, if the additional weight of the urethane (or the like) coating adds enough weight to meet or exceed the 6.25 oz requirement?