Also known as 3 of 9 or Code 39. 39 is a barcode symbology similar to codabar. 39 can represent all letters, all digits, and the characters *-.\$/+% and (space). The character * is used as a start/stop character. Since 39 can represent all letters as well as digits, the number of bars and spaces required to represent a character in 39 is longer than the number of bars and spaces required in other symbologies. 39 requires 9 bars and spaces, while codabar only requires 7. Like other barcodes, the 39 symbology involves wide and narrow bars separated by wide and narrow spaces.

```char    bsbsbsbsb
A       wnnnnwnnw
B       nnwnnwnnw
C       wnwnnwnnn
D       nnnnwwnnw
E       wnnnwwnnn
F       nnwnwwnnn
G       nnnnnwwnw
H       wnnnnwwnn
I       nnwnnwwnn
J       nnnnwwwnn
K       wnnnnnnww
L       nnwnnnnww
M       wnwnnnnwn
N       nnnnwnnww
O       wnnnwnnwn
P       nnwnwnnwn
Q       nnnnnnwww
R       wnnnnnwwn
S       nnwnnnwwn
T       nnnnwnwwn
U       wwnnnnnnw
V       nwwnnnnnw
W       wwwnnnnnn
X       nwnnwnnnw
Y       wwnnwnnnn
Z       nwwnwnnnn
0       nnnwwnwnn
1       wnnwnnnnw
2       nnwwnnnnw
3       wnwwnnnnn
4       nnnwwnnnw
5       wnnwwnnnn
6       nnwwwnnnn
7       nnnwnnwnw
8       wnnwnnwnn
9       nnwwnnwnn
-       nwnnnnwnw
.       wwnnnnwnn
(space) nwwnnnwnn
\$       nwnwnwnnn
/       nwnwnnnwn
+       nwnnnwnwn
%       nnnwnwnwn
*       nwnnwnwnn
```
b=bar s=space w=wide n=narrow