Unknown Letter

Various letters are found on some Baltimore and Kansas City trim tags. Below are some of the letters along with the Fisher Body style number it/they were found on as of July 19, 2014. Sometimes there is no space between the letters and sometimes there is. Their meaning is not documented but there are some trends that one can draw their own conclusion from.

Baltimore:
B: B has been found on Malibu sport coupe, sport sedan, convertible, 4-door sedan, Malibu series Custom El Camino, and L6 Greenbrier station wagon, sometimes with D and sometimes by itself and does NOT indicate SS396 or SS454 but does not preclude the car being an SS396 or SS454 either.
D: D has been found on Malibu sport coupe, convertible, and Malibu series Custom El Camino, sometimes with B.
L: L has been found on Custom El Caminos.

Kansas City:
L - 13637 Malibu sport coupe, 13667 Malibu convertible, 13680 El Camino (suspect this may indicate one of the two SS options but no definitive proof to date to show this).
B - Suspected to indicate color of D88 Hood & Deck stripes (black). Began appearing around February, 1970
W - Suspected to indicate color of D88 Hood & Deck stripes (white). Began appearing around February, 1970
X - 13669 Standard 4-door sedan
Z - 13337 & 13437 Standard sport coupe