think this is the Goldmine grading and pricing guide.....definitely not how it happens in the UK
Grading Records
Visual or play grading? In an ideal world, every record would be played before it is graded. In the real world, the time involved makes it impractical for most dealers, and it's rare that you get a chance to hear a record before you buy, especially if it is mailorder.
How to grade your records:
Look at everything about a record, the playing surface, the label, the edges, the cover. Then give it a grade based on the following criteria:
Mint (M): Absolutely perfect in every way, certainly never played, possibly even still sealed.
Near Mint (M-): A nearly perfect record. The record should show no obvious signs of wear. A 45 RPM or EP sleeve should have no more than the most minor defects, such as almost invisible ring wear or other signs of slight handling. An LP jacket should have no creases, folds, seam splits or any other noticeable defect. The same should be true of any inserts, such as posters, lyric sleeves, etc.
Very Good Plus (VG+): Generally worth 50 percent of the Near Mint value. A Very Good Plus record will show some signs that it was played and otherwise handled by a previous owner who took good care of it. Record surfaces may show some slight signs of wear and may have slight scuffs or very light scratches that don't affect one's listening experience. The label may have some ring wear or discoloration, but it should be barely noticeable. The center hole will not have been misshapen by repeated play. Picture sleeves and LP inner sleeves will have some slight ring wear, lightly turned-up corners, or a slight seam split. An LP jacket may have slight signs of wear or may be marred by a cut-out hole, indentation or corner indicating it was taken out of print and sold at a discount.
Very Good (VG): Generally worth 25 percent of the Near Mint value. Many of the defects found in a VG+ record will be more pronounced in a VG disc. Surface noise will be evident upon playing, especially in soft passages and during a song's intro and fade, but will not overpower the music. Groove wear will start to be noticeable, as will light scratches (deep enough to feel with a fingernail) that will affect the sound. Labels may be marred by writing, or have tape or stickers (or their residue) attached. The same will be true of picture sleeves or LP covers. However, it will not have all of these problems at the same time, only two or three of them.
Good (G) and Good Plus (G+): Generally worth 10-15 percent of the Near Mint value. A record in Good or Good Plus condition will play through without skipping. But it will have significant surface noise and scratches and visible groove wear. A sleeve or jacket will have seam splits, especially at the bottom or on the spine. Tape, writing, ring wear or other defects will start to overwhelm the object.