NOS (New Old Stock) - spare parts from the old stocks that have not been installed until now; tend to be of a better quality than the current production; some are not produced anymore

HQ - high quality

SV - side-valve engine (M-72, K-750, MW-750, Dnepr-12)

OHV - overhead-valve engine (K-650, all Ural and Dnepr except Dnepr-12)

ZIS - the oldest model of the M-72 gearbox, an exact copy of the BMW R-71 gearbox

7204 - the second oldest model of the M-72 gearbox, with non-synchronised gears

7500 - a 7204 gearbox version with synchronised gears

6204 - similar to 7500 but with a different gearchange mechanism

MT804 - Dnepr gearbox with the reverse gear

KMZ - Ucranian factory that produced M-72N, K-750, MW-750, K-650, MW-650 and all Dnepr

IMZ - Russian factory that produced M-72 (except M-72N), M-61 and all Ural

EU - European quality

2H - second-hand