Ok, this is for the purist who wants to know the date of manufacture of their Shimano components. The first letter is the year, the second one is the month:
YEAR
A 1976 B 1977 C 1978 D 1979 E 1980 F 1981
G 1982 H 1983 I 1984 J 1985 K 1986 L 1987
M 1988 N 1989 O 1990 P 1991 Q 1992 R 1993
S 1994T 1995 U 1996V 1997 W 1998X 1999 Y 2000 Z 2001 A 2002 B 2003 C 2004
MONTH
A JAN B FEB C MAR D APR E MAY F JUN G JUL
H AUG I SEP J OCT K NOV L DEC
For example my DX crankarms are stamped FB which makes them February 1981
(courtesy of rick a.k.a reily1)
