I can't find it documented anywhere, but from personal experience I've found that "Select" in front of a wood type like Mahogany usually indicates a better grade of laminate. For example, you'll see some ads state "Spruce Top" and some that state "Select Spruce Top". Both are laminate tops, but I have found that "Select" will usually be a better or best grade of laminate top or sides or back. How can you know this? And again referring back to my personal experience. If you take a guitar with a natural finished select spruce top and look at the edge of the sound hole. Notice that the laminate is thinner and that the secondary wood (the wood in the middle of the laminate) matches the top wood, i.e. same color. On guitars that state just Spruce Top the laminate is usually thicker or the secondary wood is noticeably darker, which would indicate a different species. Any that is just from what I've notice and like I said I can't find it documented anywhere to prove it, but there you go.
