Code 93 is a barcode symbology designed in 1982 by Intermec to provide a higher density and data security enhancement to Code 39. It is an alphanumeric, variable length symbology. Code 93 is used primarily by Canada Post to encode supplementary delivery information. Every symbol includes two check characters.
Each Code 93 character is nine modules wide, and always has three bars and three spaces, thus the name. Each bar and space is from 1 to 4 modules wide. (For comparison, a Code 39 character consists of five bars and five spaces, three of which are wide, for a total width of 13–16 modules.)
Code 93 is designed to encode the same 26 upper case letters, 10 digits and 7 special characters as code 39:
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z
0, 1, 2, 3, 4, 5, 6, 7, 8, 9
-, ., $, /, +, %, SPACE.
In addition to 43 characters, Code 93 defines 5 special characters (including a start/stop character), which can be combined with other characters to unambiguously represent all 128 ASCII characters.
In an open system, the minimum value of X dimension is 7.5 mils (0.19 mm). The minimum bar height is 15 percent of the symbol length or 0.25 inches (6.4 mm), whichever is greater. The starting and trailing quiet zone should be at least 0.25 inches (6.4 mm).