For raw vintage singles, the following scale is used:

Poor: The card will have multiple issues such as multiple creases, rounded corners and/or severely chipped edges.

Fair: The issues will be similar to a poor card, but with a usually better eye appeal. While there may be multiple creases, they may be a bit harder to spot on the pictures.

Good: The card may have have four rounded corners and some edge issues. There may also be a crease or two, but that crease will not show on both sides of the cards. Some older cards might show some wax stains (from the pack) on the back.

VG to VGEX: All four corners may show some wear, but should show minimal to no rounding. Unless mentioned in the title, the card should not show any creases. Upon close inspection under light, there may be some light scratches. The back may show some wax stains from a pack as well.

EX to EXMT: The card should show no rounding on the corners, but they might show some light wear. Some very light scratches maybe seen upon close inspection under light, but they should not affect the eye appeal. The back may still show some light wax staining on the back (from the pack). Centering should be roughly 80/20 or better. The image may still have some registration issues or some printing issues.

NRMT: The corners should appear sharp at first glance, but may show some light wear upon close inspection. Light chipping along the edges may be noticeable. The registration of the card should not affect the eye appeal of the card meaning that it should not stand out when looking at the card. A small printing defect is acceptable. The back should show no wax staining. Centering should be 75/25 or better.

NRMT+: The corners should appear sharp at first glance, but at most two corners may show some light wear upon closer inspection. Edge wear should be minimal. The colours of the card should show close to no fading and the registration should be on point. A small print defect may be acceptable. Centering should be 70/30 or better.

Qualifiers may be used to specify certain defects of the cards

Marked: A pencil or pen mark is seen on the card.

Min Size: The card seems to be shorter than other cards in the same set, but shows no evidence of trimming.

Trimmed: The card is shorter than other cards in the same set and shows signs that it has been cut.

Crease: This is reserved for cards in Good or VG to VGEX condition. For cards in lower grade, assume that there are creases if they aren't visible in the pictures. For cards that are EX or higher, they will not have any creases.

General Note: Assessing the condition of a card remains subjective. Please message me if you have doubts about the condition of a card and wish to get closer pictures.

Also, rough edges that are very common with OPC are not considered to be edge wear as grading companies accept them as well.