STILL SEALED : Jacket imperfections, if any, will be described. Vinyl guaranteed to be in unplayed condition.
M : I don't use this grade, on the assumption that no record or jacket is truly flawless.
M- : Vinyl appears unplayed, jacket bears no signs of wear. I rarely, if ever, use this grade.
NM : Like M-, with possible scintilla/whiff of an imperfection
VG++ : May have a couple very minor imperfections. (sleeve scuffs, faint scratches or other superficial marks that have little or no bearing on sound.) Jacket may have a couple very minor flaws.
VG+ : Like VG++, but with a few more light imperfections
VG : Several light imperfections, and possibly one or two more serious ones, such as small feelable scratches. Still plays well.
VG- : Will display numerous minor imperfections and/or feelable scratches that affect playback quality. Between you and me, you could do better.
GOOD : What I consider pretty poor... numerous major imperfections. I generally don't sell items in this range unless they are of major significance.