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The A11y Path

This blog aims to cover: W3C Guidelines, Assistive Technologies (AT), European Accessibility (EN 301 549), and more.

EN 301 549 Clause 9 Overview

Published

#was #en301549 #journal

Clause 9 is the part where the IAAP WAS BoK focuses on, This is where EN 301 549 refrences WCAG 2.0

Clause 9: Web

Conformance with WCAG 2.1 Level AA is equivalent to conforming with all of clauses 9.1 to 9.4 and the conformance requirements of clause 9.6

Clause 9.1 to 9.4 are the same as WCAG 2.1 Level AA, so I won't repeat them here.

Key takeaways:

  • Clause 9 = WCAG 2.1 Level AA: Fully adopting WCAG 2.1 Level AA is equivalent to complying with all required clauses under 9.1-9.4 + conformance clause 9.6.
  • Covers all principles (Perceivable, Operable, Understandable, Robust), but structured as:
    • 9.1 Perceivable (SC 1.x)
    • 9.2 Operable (SC 2.x)
    • 9.3 Understandable (SC 3.x)
    • 9.4 Robust (SC 4.x)
  • Void clauses (like 9.1.4.6 - 9.1.4.9) are there to maintain SC numbering alignment with WCAG 2.1, they don't require implementation, they're placeholders.
  • Clause 9.5 = WCAG 2.1 AAA Encouraged, Not Required. 9.5 lists 28 Level AAA SCs from WCAG 2.1 that are optional but recommended. These cover enhancements for:
    • Deaf/HoH users (e.g. Sign Language, Extended Audio Descriptions)
    • Low vision and cognitive support (e.g. Target Size, Help, Reading Level)
    • Refined usability (e.g. Section Headings, Error Prevention (All))
  • Clause 9.6: WCAG Conformance Requirements This part repeats WCAG's 5 core conformance conditions for Level AA:
    • Conformance Level: all SCs at Level A and AA are met.
    • Full Pages: you can't just make part of the page accessible.
    • Complete Processes: all steps in a process (e.g. checkout) must be accessible.
    • Only Accessibility-Supported Ways of Using Technologies: use methods reliably supported by AT + user agents.
    • Non-interference: even decorative or hidden content can't break accessibility (e.g. trap focus or autoplay sound).
  • EN 301 549 calls out a specific subset of SCs that must always pass, even for non-core content:
    • 9.1.4.2 Audio control
    • 9.2.1.2 No keyboard trap
    • 9.2.2.2 Pause, Stop, Hide
    • 9.2.3.1 Three flashes or below threshold

This clause formalizes WCAG into a legal/standards context, which is what makes EN 301 549 a procurement and compliance tool, not just a best-practice guide.

Requirements for non-web documents and non-web software are given in clauses 10 and 11 respectively.