NIB: New-In-Box. Unused and in the original factory carton or box, complete with all accessories.
N: New. Unused and complete with all parts as originally sold by the factory.
LN: Like New. Run once, or twice, slight marks on lug, otherwise as new.
EXC: Excellent. Run several times, slight marks on mounting lugs, slight discoloration of cylinder head or cylinder due to heat. Very slight scratches on engine. Good compression, light wear on bearing surfaces.
VG: Very Good. As for excellent, but used perhaps several hours. Still good compression, slightly enlarged mounting lug holes, one or two deep scratches or moderatelt discolored spots, small chips out of, or slightly bent fins, bearing surfaces discernably worn.
G: Good. As very good, but compression and bearing surface wear sufficient to warrent this rating. This code is considered the minimum condition of interior necessary for a "use type engine" (ie, it's got a few good hours left yet).
F: Fair. Compression sufficient to run engine, but with reduced power output. Bearing surfaces well worn, one or more missing cylinder head fins, one or more open mounting lugs, heavy scratches or blemishes one xterior, repaired parts, unacceptable as a display engine but possibly capable of G or VG rating if overhalled and/or new parts added.
P: Poor. Worn out, poor compression, will not run in present condition. Worn and/or broken and/or surfaces badly scarred. Not suitable for use or display as is. May be referred to as a "parts" engine.