Lexmark FORMS 249X Technical Reference page 150

An example of Code 39, with m = 0 and m = 1, follows:
s is the space width adjustment factor.
This parameter affects only space modules. It can be used to adjust the width of
space modules.
The range for possible s values is: -3 <= s <= 3.
0, x00 (default)
Notes:
150
Section 8: Barcodes
m = 0 (the human readable character is printed)
m = 1 (the human readable character is not printed)
248x space
s value
module adjustment
-3, xFD
-2, xFE
-1, xFF
1, x01
2, x02
3, x03
• The s value affects the actual width of the entire barcode.
To minimize the width of space modules, set s = xFD.
To maximize the width of space modules, set s = x03.
• If an invalid s value is specified, it is ignored and the default value (s
= 00) is used.
249x space
module adjustment
-3/240 inch
-2/240 inch
-1/240 inch
0
1/240 inch
2/240 inch
3/240 inch
-3/360 inch
-2/360 inch
-1/360 inch
0
1/360 inch
2/360 inch
3/360 inch