Lexmark FORMS 249X Technical Reference page 159

CODE 39
This barcode symbology uses both alphabetic and numeric characters. The
printer will add a start/stop character, '*', to the barcode and human readable
character automatically.
k value:
m value:
s value:
minimum v1, v2 values:
c parameter:
n1 value (b0 = 0):
n1 value (b0 = 1):
n2 value:
180, xB4
0 to 4, x00 to x04
-3 to 3, xFD to x03
x0E, x01 (248x)
x20, x01 (249x)
available functions:
b0, check digit
b1, human readable
1 to 255, x01 to xFF
1 to 255, x01 to xFF
0, x00
Section 8: Barcodes
159