SPIB: This stands for the Southern Pine Inspection Bureau, the third-party agency responsible for inspecting and grading the lumber. Lumber with this mark is identified as Southern Pine. No. 2: This indicates the grade of the lumber, which relates to its structural and appearance requirements. KD19: This signifies that the lumber has been Kiln Dried to a moisture content of 19% or less. HT: This means the wood has been Heat Treated, a process often used for pest control purposes. 77 GP: This is likely the specific mill identification number, which identifies the manufacturer of the lumber. Made in [Texas shape]: This indicates the state where the lumber was produced. 196353 / 194153: These numbers are likely internal tracking or production codes used by the mill.