ONIX 3 Accessibility Codes (List 196)
Introduction
This document summarizes the accessibility–related metadata codes defined in ONIX for Books 3.0 List 196. These codes enable publishers to communicate how their digital Products meet accessibility standards, which features they support, and which certification or exception applies. Our platform validates and distributes these codes so stores at {store_final_domain} can surface accurate accessibility information to end-users and institutions.
Each code is listed with its numeric value and an authoritative description. The list is grouped into logical categories to simplify lookup and implementation.
1 Summary & General Schemes
| Code | Description |
|---|---|
| 0 | Accessibility summary — ProductFormFeatureDescription stores a concise written summary or a URL that summarizes both the features provided and potential deficiencies. |
| 1 | LIA Compliance Scheme |
2 Standards & Conformance Levels
| Code | Description |
|---|---|
| 2 | EPUB Accessibility Specification 1.0 A — Conforms to EPUB A11y 1.0 and WCAG level A. The publisher may include a certification URL; otherwise the claim is self-certified. |
| 3 | EPUB Accessibility Specification 1.0 AA — Conforms to EPUB A11y 1.0 and WCAG level AA. |
| 4 | EPUB Accessibility Specification 1.1 — Conforms to EPUB A11y 1.1. Use with other codes (e.g., WCAG version and level, ARIA inclusion). |
| 5 | PDF/UA-1 — Conforms to ISO 32000-1:2008 and ISO 14289-1:2014 for universally accessible PDF. |
| 6 | PDF/UA-2 — Conforms to ISO 32000-2:2020 (PDF 2.0) and ISO 14289-2:2024. |
| 80 | WCAG v2.0 — Use with code 04 to indicate EPUB A11y 1.1 plus WCAG v2.0. |
| 81 | WCAG v2.1 |
| 82 | WCAG v2.2 |
| 84 | WCAG Level A |
| 85 | WCAG Level AA |
| 86 | WCAG Level AAA |
3 Exceptions & Limitations
| Code | Description |
|---|---|
| 8 | Unknown accessibility — Product has not been assessed or lacks information. |
| 9 | Inaccessible or known limited accessibility — Significant accessibility gaps are known. |
| 10 | No reading system accessibility options actively disabled (except as noted in EpubUsageConstraint). |
4 Navigation & Structural Features
| Code | Description |
|---|---|
| 11 | Table of contents navigation |
| 12 | Index navigation |
| 13 | Single logical reading order |
| 14 | Short alternative textual descriptions |
| 15 | Full alternative textual descriptions |
| 16 | Visualised data also available as non-graphical data |
| 17 | Accessible math content as MathML |
| 18 | Accessible chemistry content as ChemML |
| 19 | Print-equivalent page numbering |
| 20 | Synchronised pre-recorded audio |
| 21 | Text-to-speech hinting provided |
| 22 | Language tagging provided |
| 24 | Dyslexia readability options |
| 25 | Use of color is not sole means of conveying information |
| 26 | Use of high contrast between text and background color |
| 27 | Use of high contrast between foreground and background audio |
| 28 | Full alternative audio descriptions |
| 29 | Next / Previous structural navigation |
| 30 | ARIA roles provided |
| 31 | Accessible controls provided |
| 32 | Landmark navigation |
| 34 | Accessible chemistry content (as MathML) |
| 35 | Accessible math content (as LaTeX) |
| 36 | Appearance of all textual content can be modified |
| 37 | Use of ultra-high contrast between text foreground and background |
| 38 | Unusual words or abbreviations explained |
| 39 | Supplementary material to an audiobook is accessible |
| 40 | Link purposes clear |
| 41 | Page list navigation |
| 51 | All non-decorative content supports reading via pre-recorded audio |
| 52 | All non-decorative content supports reading without sight |
| 53 | Described math content |
| 54 | Accessible chemistry content (as LaTeX) |
5 Regulatory Exceptions (European Accessibility Act)
| Code | Description |
|---|---|
| 75 | EAA exception 1 – Micro-enterprises |
| 76 | EAA exception 2 – Disproportionate burden |
| 77 | EAA exception 3 – Fundamental alteration |
6 Certification, Assessment & Additional Information
| Code | Description |
|---|---|
| 90 | Compliance certification by (name) |
| 91 | Latest accessibility assessment date (YYYYMMDD) |
| 92 | Accessibility addendum |
| 93 | Compliance certification by (URL) |
| 94 | Compliance web page for detailed accessibility information |
| 95 | Trusted intermediary's web page for detailed accessibility information |
| 96 | Publisher's web page for detailed accessibility information |
| 97 | Compatibility tested |
| 98 | Trusted intermediary contact |
| 99 | Publisher contact for further accessibility information |
Usage Guidelines
Publishers should embed the relevant ProductFormFeature elements within their ONIX 3 product records, repeating the composite for each applicable code. Where a description or URL is required, include it in ProductFormFeatureDescription.
When our ingestion pipeline receives an ONIX file, we automatically map codes from List 196 to internal flags that power store-level accessibility badges and filters. Supplying accurate, up-to-date information improves discovery for institutions that mandate compliance with accessibility standards.