Overview
ISO/IEC 21471:2025 - Information technology - Automatic identification and data capture techniques - Data Matrix Rectangular Extension (DMRE) bar code symbology specification - defines the standardized requirements for the DMRE two‑dimensional (2D) barcode. Published as the second edition in 2025, the standard extends ISO/IEC 16022 by adding rectangular matrix formats while preserving the same module placement, decoding and Reed–Solomon error‑correction algorithms. ISO/IEC 21471 applies to DMRE symbols produced by any printing or marking technology and includes symbol characteristics, encodation rules, dimensions, print quality, error correction, and a reference decoding algorithm.
Key topics and technical requirements
- Symbology characteristics: DMRE is a 2D rectangular matrix composed of nominally square modules inside a finder pattern; orientation‑independent and supports reflectance reversal (light‑on‑dark or dark‑on‑light).
- Character set & encodation: Encodable characters include ASCII 0–127 (IRV), extended ASCII 128–255 (ISO/IEC 8859‑1), plus Extended Channel Interpretations (ECI) for other character sets and industry encodings.
- Symbol sizes & capacities: Rectangular sizes range from 8 × 48 to 26 × 64 (even values only). Maximum data capacities for the largest DMRE symbol: alphanumeric up to 175 characters, 8‑bit byte data 116 bytes, numeric up to 236 digits.
- Error detection & correction: Uses Reed–Solomon error correction; Annex B provides generator polynomial details. Structured append supports up to 16 symbols for segmented data storage.
- Quality & print requirements: Specifies symbol dimensions, quiet zones, and print/mark quality tests (references ISO/IEC 15415 and ISO/IEC 29158 for DPM).
- Decoding: Includes a reference decode algorithm and user-selectable application parameters to ensure interoperability.
- Compatibility note: Original square Data Matrix sizes remain defined in ISO/IEC 16022; DMRE‑enabled scanners/printers are required to recognize rectangular formats.
Practical applications and users
DMRE is intended for environments that need compact, high‑density rectangular 2D barcodes:
- Manufacturers and label printers adding rectangular formats to existing Data Matrix deployments
- Barcode scanner and marking equipment vendors implementing firmware and decoding algorithms
- Supply chain, logistics, healthcare, and electronics sectors needing higher capacity or non‑square symbol layouts
- Direct Part Marking (DPM) and industrial marking applications where rectangular space constraints exist
- System integrators building AIDC systems that require robust error correction, ECI support, and structured append
Related standards
ISO/IEC 21471:2025 is essential for anyone implementing or specifying rectangular Data Matrix barcodes (DMRE) to ensure interoperability, print quality, and reliable decoding across diverse marking and scanning technologies.
