Many technical terms used in the Rules of the National Hardwood Lumber Association and in the hardwood lumber industry are defined and explained. The Rules themselves are explained and their application is described and illustrated in the grading of many typical boards. Guidelines are provided for edging and trimming hardwood lumber to maximize its value within the constraint of market acceptability. Separate explanations are provided for each grade, and for special board types such as boards from sweepy logs, miscut boards, tapered boards, etc. Another chapter is devoted to mill equipment, operator aids, and mill design, as they affect lumber value yield.