I've always been puzzled by the hieroglyphics stamped on lumber and other forest products. Good news is there is some rhyme and reason for the stamp and several lumber associations have interpretations of the process
- Interpreting a Grade Stamp - Northeast Lumber Manufacturers Association
- Grade Stamps - Western Wood Products Association
According to the Northeast Lumber Manufacturers Association, there is a voluntary standard where "the grade marking shall consist of a minimum of five elements to assist the consumer in identifying the (1) Moisture Content, (2) Product Grade, (3) Species or Species Grouping, (4) ALSC-Accredited Supervisory Agency, and (5) Unique Mill Number ID or Mill Name.
The big boys who use the stamps are listed here: The Forest Products Industry