# Which schema.org accessibility properties must an EPUB package document carry, which are only recommended, and what pitfalls do the W3C documents themselves warn about?

- id: art_01M5MYH5DYGCREBQNTC5E9CD05
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T16, T20 · tags: none
- updated: 2026-10-23T17:56:52.792Z
- url: https://veyrul.com/articles/art_01M5MYH5DYGCREBQNTC5E9CD05

At EPUB Accessibility 1.1 (W3C Recommendation, 17 October 2024) every EPUB publication MUST carry schema.org accessMode, accessibilityFeature and accessibilityHazard in its package document, and SHOULD carry accessibilitySummary and accessModeSufficient; metadata only in a linked record does not count. The Techniques Note (13 March 2025, advisory) adds how to fill them: access modes describe the default content, not adaptations; sufficient modes carry the adaptations; hazards may be stated positively or negatively; "none"/"unknown" feature values cannot satisfy the requirement. The Note has internal typos in its hazard example that an agent should not copy.

At EPUB Accessibility 1.1 (W3C Recommendation, 17 October 2024) every EPUB publication MUST carry schema.org accessMode, accessibilityFeature and accessibilityHazard in its package document, and SHOULD carry accessibilitySummary and accessModeSufficient; metadata only in a linked record does not count. The Techniques Note (13 March 2025, advisory) adds how to fill them: access modes describe the default content, not adaptations; sufficient modes carry the adaptations; hazards may be stated positively or negatively; "none"/"unknown" feature values cannot satisfy the requirement. The Note has internal typos in its hazard example that an agent should not copy.

Curator qualifications: EPUB Accessibility 1.1: accessMode, accessibilityFeature, accessibilityHazard MUST be in the package document; summary and accessModeSufficient SHOULD; Techniques Note guidance.

Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

```json
{
  "citations": [
    {
      "url": "https://www.w3.org/TR/epub-a11y-11",
      "note": "cited at https://www.w3.org/TR/2024/REC-epub-a11y-11-20241017/; candidate evidence excerpts"
    },
    {
      "url": "https://www.w3.org/TR/epub-a11y-tech-11",
      "note": "cited at https://www.w3.org/TR/2025/NOTE-epub-a11y-tech-11-20250313/; candidate evidence excerpts"
    },
    {
      "url": "https://www.w3.org/TR/2024/REC-epub-a11y-11-20241017/",
      "note": "observed URL (dated/alias form of the cited catalogue source; canonical identity retained)"
    },
    {
      "url": "https://www.w3.org/TR/2025/NOTE-epub-a11y-tech-11-20250313/",
      "note": "observed URL (dated/alias form of the cited catalogue source; canonical identity retained)"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] At EPUB Accessibility 1.1 (W3C Recommendation, 17 October 2024) every EPUB publication MUST carry schema.org accessMode, accessibilityFeature and accessibilityHazard in its package document, and SHOULD carry accessibilitySummary and accessModeSufficient; metadata only in a linked record does not count. The Techniques Note (13 March 2025, advisory) adds how to fill them: access modes describe the default content, not adaptations; sufficient modes carry the adaptations; hazards may be stated positively or negatively; "none"/"unknown" feature values cannot satisfy the requirement. The Note has internal typos in its hazard example that an agent should not copy. · locator: cited at https://www.w3.org/TR/2024/REC-epub-a11y-11-20241017/; candidate evidence excerpts · source: https://www.w3.org/TR/epub-a11y-11

Rights:
- documentation: license=unknown hosting=permitted redistribution=permitted modification=unknown training=unknown · Applies to this original summary only, not to the cited sources.

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