Code 93
Intermec introduced Code 93 in 1982 as a denser successor to its own Code 39, keeping variable-length alphanumeric encoding while shortening the symbol by roughly a quarter for identical data. Each character occupies nine modules across three bars and three spaces, and two check characters computed from weighted modulo-47 sums replace the single-character self-checking of the earlier design. Full ASCII is reachable through shift characters that pair a control symbol with a base character. The 0.19 mm X-dimension and ten-module quiet zones match Code 39, so the saving comes entirely from the encoding rather than from finer printing. Code 93 appears on logistics labels where print area is constrained but a two-dimensional symbol would be unnecessary. It remains a linear, non-GS1 carrier.
A higher-density improvement over Code 39 that encodes the full ASCII 128 character set using two check characters for enhanced reliability. Code 93 produces barcodes approximately 25% shorter than Code 39 for the same data, making it suitable for logistics labels with limited print area.