The way I've been reading the CMSNL parts fiches is that the A,B,C,D designation after the model refers to the year. First year is blank or an A, next is B. So the CB250NE would be the 5th or possibly the 6th year of production. This changes also depending on the country as some countries started receiving a model a year or 2 later than others and so each country started with A but could be a couple of years later than another country which could be on the B or C designation. Make sense?