Extremely Fine (XF) - Nearly perfectly centered.
Very Fine (VF) - Slightly off-center on one side, with the design well clear of the edge. Imperforate stamps have three margins at least normal size.
Fine/VF (F-VF) - Off-center on one side, or only slightly off-center on two sides. Imperforate stamps have two margins at least normal size and the design does not touch the edge. Many early issues are printed in such a way that the design is naturally very close to the edge.
Fine (F) - Noticeably off-center on two sides. Imperforate stamps may have small margins. Earlier issues may show the design touching one edge of the stamp.
Ave/Fine (Ave-F) - Design cutting one edge of the stamp.
Average (Ave) - Design cutting two edges of the stamp.
NH (Never Hinged) - Full original gum with no hinge mark or other blemish or disturbance.
LH (Lightly Hinged) - Full original gum with a light disturbance of the gum, usually from the removal of a hinge.
OG (Original Gum) - Hinging and/or other disturbances affecting up to 20% of the gum.
PG (Partial Gum) - Includes 20% to 80% of the original gum. The stamp may have hinge remnants.
RG (Regummed) - Believed to have been regummed.
NG (No Gum) - Includes less than 20% of the original gum.
HH (Heavily Hinged) - Includes multiple hinges or a particularly heavy hinge.