Allowable Imperfections defined as - Small Pin Knots (back face only), Worm Holes (back face only), Roey/Scale Grain (back face only), Planer Skip/Tear Out (back face only), Sapwood (back face only), Small drying cracks, small end splits (less than 5/32 inches in width), that do not impair the strength of the material or fastening, Discoloration caused by weathering or chemical reaction, Bow or twist which can be removed using normal installation methods and tools.