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 - 13637 Malibu sport coupe, 13667 Malibu convertible, 13437 Chevelle sport coupe, 135/13669 Malibu 4-door sedan, and Monte Carlo
B D - 13637 Malibu sport coupe, 13667 Malibu convertible, 13680 Malibu sedan pickup

Kansas City:
L - 13637 Malibu sport coupe, 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) but not confirmed. Began appearing around February, 1970
W - Suspected to indicate color of D88 Hood & Deck stripes (white) but not confirmed. Began appearing around February, 1970
X - 13669 Standard 4-door sedan
Z - 13437 Chevelle sport coupe, 13380 El Camino