Overview
ISO/TR 11548-2:2001 - Communication aids for blind persons defines how 8‑dot Braille patterns are assigned (mapped) to Latin alphabet based 8‑bit coded character sets. The Technical Report provides semantic assignation (meanings) for each 8‑dot Braille pattern so that Braille input/output devices, interfaces and software can exchange data consistently between tactile Braille and sighted text. It does not cover 6‑dot Braille or any physical dimensions of Braille cells.
Key topics
- Scope and purpose: Establishes mapping of 8‑dot Braille to Latin‑based 8‑bit code tables to support interoperability of assistive technology.
- Semantic assignation: Uses tables where each Braille pattern can have multiple meanings distinguished by rank numbers; the primary meaning is rank 0. Unambiguous meaning is indicated by shift marks (SM1, SM2, SM3) and rank indicators.
- Reference tables:
- Table 1 & Table 2 - Assignations of Braille patterns to meanings (sorted by Braille identifiers and by character meanings respectively).
- Table 3 - Complete Braille equivalent aligned as closely as possible with Latin Alphabet No.1 (ISO/IEC 8859‑1) and including control characters for a full 256‑value table.
- Annex A (Tables A.1 & A.2) - Additional mappings for commonly used PC code pages (referred to as PC1 = code page 850 and PC2 = code page 437).
- Shifting conventions: Specifies how to indicate a switch to Latin alphabet based character sets using SHIFT MARK ONE/TWO and a character set indicator (B100), per ISO/TR 11548‑1.
- Intended audience: Experts, manufacturers and developers working on 8‑dot Braille hardware and software.
Applications
- Development and testing of Braille displays, embossers, tactile printers and Braille input devices that support 8‑dot Braille.
- Software for screen‑to‑Braille translation, Braille drivers, accessibility middleware and data‑exchange formats between Braille and visual text systems.
- Ensuring interoperability between assistive devices and host systems by providing a standardized mapping to common 8‑bit code tables.
- Supporting localization and multi‑language support where Latin‑based character sets are involved.
Who should use this standard
- Assistive‑technology manufacturers and firmware developers
- Accessibility software engineers and system integrators
- Standards experts and test laboratories validating Braille‑enabled products
Related standards
Use ISO/TR 11548‑2 when you need a reliable, standards‑based mapping between 8‑dot Braille and Latin‑based 8‑bit character sets to ensure consistent data exchange and device interoperability in assistive technology.
Open preview (PDF)Communication aids for blind persons — Identifiers, names and assignation to coded character sets for 8-dot Braille characters — Part 2: Latin alphabet based character sets
