Accessibility Guidelines and Standards | Accessibility Resources

Current Standards and Recommendations

CEN, CENELEC, ETSI: EN 301 549 V3.2.1 (2021-07): Accessibility requirements for ICT products and services (PDF).
Older version of EN 301 549
W3C: Web Content Accessibility Guidelines (WCAG) 2.2: W3C Recommendation 05 October 2023.
W3C: Web Content Accessibility Guidelines (WCAG) 2.1: W3C Recommendation 21 September 2023. This replaces the original version, which was published in 2018. The new version has a note added to Success Criterion 4.1.1 Parsing saying that this criterion should be considered as always satisfied for any content using HTML or XML.
Older versions of WCAG
- Web Content Accessibility Guidelines (WCAG) 2.1: W3C Recommendation 05 June 2018.
- Web Content Accessibility Guidelines (WCAG) 2.0 – W3C Recommendation 11 December 2008.
W3C: Accessible Rich Internet Applications (WAI-ARIA) 1.2: W3C Recommendation 06 June 2023.
Older versions of WAI-ARIA
- Accessible Rich Internet Applications (WAI-ARIA) 1.1: W3C Recommendation 14 December 2017.
- Accessible Rich Internet Applications (WAI-ARIA) 1.0: W3C Recommendation 20 March 2014.
W3C: ARIA Authoring Practices Guide (APG).
W3C: ARIA in HTML: W3C Recommendation 7 May 2024.
W3C: Accessible Name and Description Computation 1.1: W3C Recommendation 18 December 2018 . This specification is targeted at user agent developers.
W3C: Authoring Tool Accessibility Guidelines (ATAG) 2.0: W3C Recommendation 24 September 2015.
Description of ATAG 2.0
Guidelines for tools that produce web content, such as WYSIWYG HTML editors, web content management systems, software for creating mobile web applications, and tools convert or export to web content. The guidelines are divided into two parts: Part A covers guidelines for the user interface of authoring tools, while Part B covers guidelines for the content produced with such tools.
W3C: User Agent Accessibility Guidelines (UAAG) 2.0: W3C Working Group Note 15 December 2015.
Description of UAAG 2.0
Guidelines for for web browsers and similar applications (including media players and browser extensions) that render web content.
WAI-ARIA Graphics Module: W3C Recommendation 02 October 2018: a specification that is less well known and, as of late 2022, probably not well supported by assistive technologies.
WAI-Adapt Explainer: W3C Group Draft Note 03 January 2023 (previously published as “Personalization Semantics Explainer”).

Resources about Web Accessibility Standards

About WAI-ARIA

Accessible Rich Internet Applications (WAI-ARIA) 1.0 was the first official version of a specification of an ontology of roles, states and properties that can be used to improve the accessibility of web applications.
This document is part of a suite of documents. The best starting point is the WAI-ARIA Overview. For developers of web applications or widgets, the following documents are especially important:

WAI-ARIA 1.0 Primer: An introduction to rich Internet application accessibility challenges and solutions. This document has not been updated since July 2016.
ARIA Authoring Practices Guide (APG). The guide was published in this form mid May 2022 to replace the single page working group Note (see below).
WAI-ARIA Authoring Practices 1.1: this Working Group Note provides guidance on several aspects of creating accessible rich internet applications: design patterns and widgets, landmark regions, accessible names and descriptions, developing a keyboard interface, grid and table properties, hiding semantics using the presentation role, and role that hide other semantics. (version 1.0 was subtitled “An author's guide to understanding and implementing Accessible Rich Internet Applications”.) This document now redirects to a subsite of the WAI (see above).
ARIA in HTML: W3C Recommendation 21 December 2023.
HTMLAccessibility API Mappings 1.0: W3C Working Draft 04 December 2023: This specification defines how HTML user agents respond to and expose role, state and property information provided for Web content.
Core Accessibility API Mappings 1.1: W3C Recommendation 14 December 2017. This document describes how user agents should expose semantics of web content languages to accessibility APIs. This helps users with disabilities to obtain and interact with information using assistive technologies.
Core Accessibility API Mappings 1.2: W3C Candidate Recommendation Draft 02 November 2023.
WAI-ARIA 1.0 User Agent Implementation Guide: W3C Recommendation 20 March 2014. This older document has been replaced by newer ones that describe API mappings. See WAI-ARIA Overview.
Garaventa, Bryan: The ARIA Role Matrices, Apex 4X (no date; accessed on 07.11.2024).

About WCAG 2.2

Documents Accompanying WCAG 2.2

W3C: Web Content Accessibility Guidelines (WCAG) Overview: this is a good starting point for people who are new to these guidelines.
All WCAG 2.2 Understanding Docs.
W3C: How to Meet WCAG 2 (Quick Reference) [for WCAG 2.2]: A customizable quick reference to Web Content Accessibility Guidelines (WCAG) 2 requirements (success criteria) and techniques.
This site allows developers to filter the techniques based on the conformance level and the technologies that apply to the content they are creating.
See also Techniques for WCAG 2.2.
What's New in WCAG 2.2, Web Accessibility Initiative (WAI), W3C, last updated on 05.10.2023 (accessed on 29.12.2023).

Articles and Blogposts about WCAG 2.2

Understanding WCAG 2.2, Gov.UK Service Manual, 05.10.2023.
Hick, Andrew: WCAG 2.2 map by theme, Andrew Hick (no date; accessed on 26.08.2024; Creative Commons licence: CC BY-NC 4.0)
The WCAG Explained: Simplified and actionable explanations of every WCAG 2.2 criteria. By Stark Lab. (No date; accessed on 26.08.2024.)
Maniez, Audrey: WCAG 2.2 : enfin la publication tant attendue !, Access42, 05.10.2023.
Strobbe, Christophe: Wat verandert er voor overheidswebsites na de publicatie van WCAG 2.2?, Eleven Ways, 05.10.2023.
Stein, Joshua A.; Blank, Shira M.; Strobach, Steven, A.: They Finally Hit Refresh: After More Than a Year of Delays, It Is Time to Officially Welcome WCAG 2.2, Workforce Bulletin, Epstein Becker & Green, 06.10.2023.
Montgomery, Rachel Bradley: AG Working Group - What’s Next, LinkedIn, 18.08.2023.
This article discusses WCAG2ICT, WCAG 3, how the working group works and how to get involved.
Edwards, James: New Success Criteria in WCAG 2.2, TPGi, 19.08.2022.
Roselli, Adrian: The 411 on 4.1.1, Adrian Roselli, 05.12.2022, updated on 06.06.2023.
Quote: For quick background, this started when one of the authors of 4.1.1 filed an issue in June 2022 (or 13½ years after 4.1.1 was released with WCAG 2) to clarify the language: #2525 Proposal to Rephrase Success Criterion 4.1.1.
de Oliveira, Domingos: WAI und WCAG brauchen eine Revolution, Barrierefreiheit | Schulung, Begleitung und Tests,, 07.08.2023.
Strobbe, Christophe: The Troublesome Life and Lamentable Death of Success Criterion 4.1.1, Eleven Ways, 09.02.2023. (Originally published on Medium.)
Tarnoff, Nat: Going Beyond WCAG, Nat Tarnoff, 23.09.2024.

One of the most frequently misunderstood success criteria in WCAG 2.0 and WCAG 2.1 is Success Criterion 4.1.1 Parsing. For a discussion of this criterion and a set of test pages, see Understanding and Testing WCAG 2.1 Success Criterion 4.1.1 on the website Accessibility Works.

About WCAG 2.1

Documents Accompanying WCAG 2.1

W3C: Web Content Accessibility Guidelines (WCAG) Overview: this is a good starting point for people who are new to these guidelines.
W3C: Understanding WCAG 2.1.
This is a guide to the guidelines in general and to each success criterion in particular. See also All WCAG 2.1 Understanding Docs.
W3C: Techniques for WCAG 2.1.
This document explains how the success criteria can be implemented; it is not meant to be exhaustive: it is also possible to pass the success criteria with techniques that are not documented here.
W3C: How to Meet WCAG 2 (Quick Reference): A customizable quick reference to Web Content Accessibility Guidelines (WCAG) 2 requirements (success criteria) and techniques.
WCAG 2.1 Requirements Draft in the W3C wiki.

Articles and Blogposts about WCAG 2.1

WCAG 2.1 Primer, Gov.UK (no date; accessed on 26.08.2024).
Access Guide: website by Alex Chen (from Chicago) that explains >WCAG 2.1 in plain English (no date; accessed on 26.08.2024; Creative Commons licence: CC BY-NC 4.0).
Accessibility Not-Checklist , Intopia (no date; accessed on 26.08.2024).
The Not-Checklist acts as a guide to make sure you haven’t missed anything. If you’re new to accessibility, the resource provides a foundation – it’s an overview of what you’ll need to consider, but it won’t teach you WCAG from front to back.
Kirkpatrick, Andrew: WCAG 2.1 is a W3C Recommendation, W3C Blog, 05.06.2018.
Onsman, Ricky: What’s new in WCAG 2.1?, Intopia, 15.06.2018.
Avila, Jonathan: Does WCAG 2.1 Replace 2.0? When Should You Adopt WCAG 2.1?, Level Access, 27.06.2018.
Onsman, Ricky: Intopia Launches WCAG 2.1 Map, Intopia, 26.07.2018.
Lauke, Patrick: These aren't the SCs you're looking for ... (mis)adventures in WCAG 2.x interpretation and audits (Patrick Lauke on YouTube, 43 minutes, 04.01.2020).

Summary of “These aren't the SCs you're looking for…”
Video recording of a talk at #a11yTO Conf in Toronto, 24.10.2019. Patrick Lauke discusses a few success criteria that are often misinterpreted. For example SC 2.4.6 does not require that a web page contains headings or that labels need to be correctly associated with form controls. Success criterion 3.3.2 does not require that labels are correctly marked up using the label element or properly associated with from controls. Success criterion 2.1.1 does not contain requirements related to which specific keys need to be used to operate something. For example, a button emulated using an a element cannot be activated using the space bar, even though that is standard behaviour for a button, but would still pass SC 2.1.1. Success criterion 3.2.3 is about the order of the navigation in relation to the rest of the page. Success criterion 1.3.3 does not prohibit the use of colour, shapes etcetera in controls; however, instructions for using those controls must not exclusively rely on these characteristics.
Patrick Lauke also discusses “cascades of fail”, i.e. when something fails several success criteria. For example, a link containing only an image without an alt attribute fails multiple success criteria. Auditors within the same organisation need to rate this consistently.
WAG is not perfect. Some success criteria appear to be subjective. For example, what is “equivalent purpose” in SC 1.1.1? What is “conveyed by the presentation” in SC 1.3.1? What is descriptive enough for SC for 2.4.6?
Some success criteria have loopholes. For example, what does “visible” mean in SC 2.4.7? According to the letter of the success criterion, a single pixel with a faint colour, would pass. WCAG 2.1 tried to patch loopholes by adding new SCs instead of modifying existing ones. SC 1.4.11 is meant to patch a loophole in SC 2.4.7, since it applies to the focus state of components, but a single pixel used as a focus indicator would still pass. It also does not cover the contrast between the focused and the unfocused state of controls. Failure F73 tries to close another loophole by redefining “colour” in non-normative text.
Some success criteria are overly specific and apply only in very specific situations. For example, SC 1.4.10 (Reflow) is meant to help low-vision users who need to zoom in and should not need to scroll both horizontally and vertically, and also specifies a width in CSS pixels. SC 1.4.12 (Text spacing) is so specific that it does not always apply.
See also the slides for “These aren't the SCs you're looking for…”.
WCAG 2.1 Adoption in Europe, W3C Blog, 13.09.2018.

Translations of WCAG 2.1

Articles and Blogposts Published While WCAG 2.1 Was Being Written

Updated W3C Recommendation: Web Content Accessibility Guidelines (WCAG) 2.1, W3C News, 21.09.2023.
Kirkpatrick, Andrew: WCAG 2.1 is a Candidate Recommendation, W3C Blog, 30.01.2018.

Main points of “WCAG 2.1 is a Candidate Recommendation”
The Accessibility Guidelines Working Group is looking for implementations for each of the success criteria in WCAG 2.1 in order to move to the next stage in the standardisation process. Some of the new success criteria are “at risk”, which means that the Working Group is unsure if implementation testing or public review will validate those success criteria for the final guidelines. (Apparently, the Candidate Recommendation stage does not require at least two independent implementations but adequate implementation experience. The 2005 version of the W3C Process Document also said, The Working Group is not required to show that a technical report has two independent and interoperable implementations as part of a request to the Director to announce a Call for Implementations.)
McDonald, David: WCAG 2.1: The final list of candidate Success Criteria is here, CanAdapt, August 2017.
Roselli, Adrian: What’s New in WCAG 2.1, Adrian Roselli's blog, 23.08.2017.
Access42: Les nouveautés des WCAG 2.1, Access42, 10.08.2017.
Marchak, Erin: Usability and Accessibility: The new WCAG 2.1 and Nielsen’s 10 Usability Heuristics, Myplanet, 10.10.2017.
Sims, Glenda: Understanding WCAG 2.1 – Reviewing Low Vision Success Criteria, The Deque Blog, 14.12.2017.
Das Schicksal von "Target Size", Incobs, 01.02.2018.
Gower, Michael: Simplifying the New WCAG 2.1 Guidelines, IBM Age and Ability blog, 08.02.2018.
Garaventa, Bryan: Differences between ARIA 1.0 and 1.1: Changes to role="combobox", Level Access, 27.01.2017.
Experimental code related to personalised accessibility for cognitive impairments:
- W3C Cognitive Accessibility Task Force: Easy Personalization.
- coga.personalisation on GitHub.
Sims, Glenda: WCAG 2.1: What is Next for Accessibility Guidelines, Deque blog, 24.04.2018.
Rietveld, Rian: We need to talk about WCAG, Level Level Rotterdam, 18.05.2021.
Dennis Lembrée tweeted this blog post, pulling out one specific quote: Stop adding new Success Criteria before the most recent ones have been properly documented, explained and better adopted into websites worldwide.
Sims, Glenda: Understanding WCAG 2.1: A History of WCAG, Deque blog, 01.11.2017.
Sims, Glenda: Understanding WCAG 2.1 – Reviewing Cognitive Success Criteria, The Deque Blog, 09.01.2018.
Mattes, Kurt: WCAG 2.1: Success Criteria for Cognitive Disabilities, The Paciello Group blog, 01.03.2018.

About WCAG 2.0

Documents Accompanying WCAG 2.0

W3C: Understanding WCAG 2.0: A guide to understanding and implementing Web Content Accessibility Guidelines 2.0.
This is a guide to the guidelines in general and to each success criterion in particular.
W3C: Techniques for WCAG 2.0: Techniques and Failures for Web Content Accessibility Guidelines 2.0.
This document explains how the success criteria can be implemented; it is not meant to be exhaustive: it is also possible to pass the success criteria with techniques that are not documented here. This document was last updated on 07.10.2016.
W3C: How to Meet WCAG 2.0: A customizable quick reference to Web Content Accessibility Guidelines 2.0 requirements (success criteria) and techniques.
This site allows developers to filter the techniques based on the conformance level and the technologies that apply to the content they are creating. This link now redirects to a version based on WCAG 2.2.
Requirements for WCAG 2.0: W3C Working Draft 12 February 2002.
Requirements for WCAG 2.0 Checklists and Techniques: W3C Working Draft 26 April 2005.

Translations of WCAG 2.0

See Translations of WCAG 2.0.

Articles and Blogposts about WCAG 2.0

Viget: Interactive WCAG 2.0.
Wuhcag: WCAG 2.0 checklists: three checklists for levels A, AA and AAA, respectively. The checklists are also available as PDF files.
Pennsylvania State University: WCAG 2.0 Guidelines: summaries of the guidelines for Webmasters who may have some knowledge of HTML or programming.
Hentry, Herin: WCAG is not scary anymore - A progressive approach to Website Accessibility, LinkedIn Pulse, 25.07.2016.
Campbell, Alastair: Web accessibility guidelines and how to use them, Nomensa blog, 22.11.2017.
Hassell, Jonathan: The future of WCAG – maximising its strengths not its weaknesses, Hassell Inclusion blog, 07.01.2013.
Eggert, Eric: WCAG 2: Guidelines and Guardrails, Eric Eggert, 29.12.2023.
See also David Sloan's LinkedIn post (26.11.2024): [The guidelines are] the "above and beyond" people are looking for when realizing that conformance with WCAG's SCs is just the start. So let's celebrate their existence and make more use of them!

About WCAG 3.0

Fiers, Wilco: W3C unveils 174 new outcomes for WCAG 3.0, Deque Blog, 16.05.2024.

Resources about EN 301 549

Chapters 9 (Web), 10 (Non-web documents) and 11 (Software) are based on WCAG 2. Chapters 4–7 and 12–13 define additional accessibility requirements.

Latest changes to accessibility standard, Shaping Europe’s digital future (European Commission) (no date; accessed on 10.01.2023).
This page lists the changes between v2.1.2 and v3.2.1 of EN 301 549, the requirements that are not in WCAG 2.1 and the requirements in EN 301 549 that are not relevant to the Web Accessibility Directive.
EN 301 549: videos about the standard created by Funka (sponsored by Microsoft) in 2017 and made available under the terms of a Creative Commons licence.
Human Factor TC / EN 301 549, ETSI GitLab (no date; accessed on 05.07.2022).
See also Susanna Laurin's LinkedIn post from early September 2024, asking accessibility experts to contributing to the revision or creation of accessibility standards for the European Union's accessibility legislation in 2025: The EU is launching a very ambitious accessibility legislation in 2025, and we need all brilliant minds to come together to make sure the technical specifications are supporting end users with disabilities, understandable and measurable for surveillance agencies. If you don't have the time or resources to become part of the standardisation family, please just comment, ask questions and make your voice heard!
Learn about EN 301 549 from Funka, Accessible TechComm, July 2016.
CEN/CLC/ETSI/JWG eAcc — eAccessibility: web page of the joint working group in charge of updating EN 301 549 for the European Accessibility Act under the European Commission's Standardization Request M/587. See also Accessibility in CEN's business sectors.
See also Accessibility in CEN-CENELEC Topics, which also mentions three technical reports that are updated alongside EN 301 549: CEN/CLC/ETSI TR 101550:2022, CEN/CLC/ETSI TR 101551:2014 and CEN/CLC/ETSI/TR 101552:2014.
CAN/ASC - EN 301 549:2024 Accessibility requirements for ICT products and services (EN 301 549:2021, IDT), Accessibility Standards Canada, last updated on 30.05.2024 (accessed on 04.06.2024).
This is an online version of EN 301 549 version 3.2.1 (identified as the version approved by CEN on 23 April 2021).
EN 301 549 Accessibility requirements for ICT products and services, Accessibility Standards Canada, last updated on 06.02.2024.
This is an online version of EN 301 549 version 2.1.2 from August 2018, which was superseded in the European Union by version 3.2.1 in March 2021.
Update on 03.06.2024: this version was replaced by version 3.2.1, listed above.
~~Standard - EN 301 549: Accessible ICT Procurement Toolkit.~~
What is the European accessibility standard EN 301 549? (Deque Systems on YouTube, 12 minutes, 18.02.2019.
This is an introduction to the standard presented as an interview with Shadi Abou-Zahra of the World Wide Web Consortium (W3C).
Norme NBN EN 301549:2021, NBN (no date; accessed on 16.12.2022).

Issues in EN 301 549

Some requirements in EN 301 549 are untestable because nobody knows how to apply them. These requirements include 11.1.4.10 (Reflow) for applications, 6.1 (Audio bandwidth for speech), 6.5.2 (Resolution) and 6.5.3 (Frame rate).

Seeking official discussion of SC 1.4.10 Reflow on native mobile apps, WCAG2ICT issue tracker, 06.10.2018.
No consensus was reached in the comment on this issue. See also the related issue Success Criterion 1.4.10: Reflow (Level AA) (opened on 08.02.2023). The WCAG2ICT Working Group Note of September 2013 did not cover success criterion 1.4.10. The WCAG2ICT Editor's Draft (version of 31.10.2023) contains a note saying, the WCAG2ICT Task Force would like feedback on whether the guidance for non-web software is sufficient, or if there are other considerations that should be covered in the notes in the WCAG2ICT guidance below.

Translations of EN 301 549

The national standardisation bodies in some European member states provide translations of the European standard. Below are a few examples.

AFNOR's French translation, NF EN 301549 (435,88 € as of 09.01.2013).
NBN's French translation (170 € as of 09.01.2023).
UNE's Spanish translation.
DIN EN 301549 Barrierefreiheitsanforderungen für IKT-Produkte und -Dienstleistungen.

Other Accessibility Standards

CEN: EN 17161:2019: Design for All - Accessibility following a Design for All approach in products, goods and services - Extending the range of users. See also the news item New CEN standard: EN 17161:2019 on Accessibility (no date; accessed on 20.05.2019).
See also Standard I.S. EN 17161:2019 – Design for All, Centre for Excellence in Universal Design (no date; accessed on 11.05.2022).
CEN: EN 17210:2021, CEN/CLC/JTC 11 - Accessibility in the built environment (no date; accessed on 11.05.2022).
See also EN 17210:2021 contributes to an accessible and usable built environment (18.03.2021).
ISO and IEC: ISO/IEC 30071-1:2019: Information technology — Development of user interface accessibility — Part 1: Code of practice for creating accessible ICT products and services.
Details about ISO/IEC 30071-1:2019
Below is the standard's abstract:
This document takes a holistic approach to the accessibility of information and communications technology (ICT) by combining guidance on implementing the accessibility of ICT systems (ICT accessibility) both at organizational and system development levels.

This document gives guidelines for building and maintaining ICT systems (including products and services) that are accessible to diverse users (including users with disabilities and older people).

This document is applicable to all types of organizations. This document applies to the breadth of ICT systems and the results of convergent and emerging technologies within an organization including, but not limited to: information systems; intranet systems; websites; mobile and wearable applications; social media; and Internet of Things (IoT) systems.

It gives requirements and recommendations for organizations:
1. ensuring accessibility is considered in their policies or strategy by creating an organizational ICT accessibility policy;
2. embedding the consideration of accessibility decisions through the entire process of developing procuring, installing, operating and maintaining ICT systems, and documenting these choices;
3. justifying decisions on accessibility;
4. communicating the ICT system's accessibility decisions to its users at launch, through creating and publishing its accessibility statement.
See also ISO 30071-1 digital accessibility standard – all you need to know (supersedes BS 8878) (Hassell Inclusion, 07.09.2019) and ISO 30071-1 Digital Accessibility Maturity Scorecard (Hassell Inclusion, no date; accessed on 22.09.2023).
Référentiel Général d'Accessibilité pour les Administrations (RGAA): version 4.1 of the accessibility guidelines for public authorities in France.
See also Politique de contribution aux logiciels libres de l’État. The guidelines are also available in Markdown format on GitHub: RGAA Référentiel. (An English translation of version 3 is available in the GitHub repository RGAA Guidelines.)
United Nations: Accessibility Guidelines for United Nations Websites (last accessed on 15.04.2022).
ISO and IEC: ISO and IEC 29136:2012: Information technology — User interfaces — Accessibility of personal computer hardware.
Abstract of ISO and IEC 29136:2012

ISO/IEC 29136:2012 provides requirements and recommendations for the accessibility of personal computer hardware, to be used when planning, developing, designing and distributing these computers. While it does not cover the behaviour of, or requirements for, assistive technologies, it does address connectivity of assistive technologies as an integrated component of interactive systems. Some requirements or recommendations in ISO/IEC 29136:2012 require software support; however, requirements and recommendations that solely focus on software are not included in ISO/IEC 29136:2012.
ISO and IEC: ISO/IEC 29138-1:2018: Information technology — User interface accessibility — Part 1: User accessibility needs.
Abstract of ISO and IEC 29138-1:2018

This document identifies a collection of user accessibility needs that diverse users have of ICT systems to make these systems accessible to them. Each user accessibility need might be required of a system by an individual. Different users can have different sets of user accessibility needs in different contexts.

While this set of user accessibility needs was developed for the domain of ICT, many of the user accessibility needs in this set also apply in other domains.

This document does not provide requirements or specific processes and methods for the application and evaluation of user accessibility needs. However, it could inform the development of such requirements (see 5.4).

This document is not designed for certification purposes or regulatory or contractual use.

The user accessibility needs in this document are intended to inform and encourage those responsible for accessibility to go beyond the minimum provisions of accessibility legislation and regulations.
ISO and IEC: ISO/IEC 13066: Information technology — Interoperability with assistive technology (AT):

Machine-Readable Guideline Representations

Representation of the Web Content Accessibility Guidelines (WCAG) 2.0 or more recent versions in a machine-processable format:

Karl Groves / Tenon: WCAG as JSON: represent WCAG 2.2 success criteria (MIT License).
Vegard Haugstvedt: WCAG as JSON: based on WCAG 2.1 and available under the terms of the MIT licence.
Wilco Fiers: wcag2json: JSON versions of WCAG 2.0 in various languages, including English, German, Spanish and Dutch. (The repository has no licence.)
Emerge Interactive: wuhcag-json: YAML files for each individual WCAG 2.0 success criterion, and a JSON version that combines all this information into a single file. (Licence: Creative Commons Attribution-NonCommercial 4.0 International License.)
kevee: WCAG 2.0 standard in YAML and JSON format: this repository contains a YAML file containing all the success criteria with their associated techniques and failures, and a JSON file that represents the same data. The repository was last updated in November 2013 and thus represents the September 2013 version of the WCAG techniques, which is now out of date. (See the latest version of Techniques for WCAG 2.0 and the latest version of Techniques for WCAG 2.1.)

Guidelines Focusing on Specific Target Groups or Disabilities

Making Content Usable for People with Cognitive and Learning Disabilities: W3C Working Group Note 29 April 2021. This specification was developed by the Cognitive and Learning Disabilities Accessibility Task Force (Cognitive A11Y TF). See also the Cognitive Accessibility Roadmap and Gap Analysis. ~~W3C: (Making Content Usable for People with Cognitive and Learning Disabilities: W3C First Public Working Draft 11 December 2018.)~~
Aphasia United: Best practice recommendations. These recommendations are available in several languages, including Chinese, Spanish, aphasia-friendly English and aphasia-friendly Japanese.

Office Documents and E-Books

Accessible Digital Office Document (ADOD) Project: This site has published guidelines for creating accessible documents with various office suites: Microsoft Office (versions 2003 to 2013), LibreOffice and Apache OpenOffice (especially Writer), Google Docs, etcetera. The guidelines also explain how to create accessible templates and how to export documents to “tagged” PDF. For some of these documents, French and Dutch translations are also available.
IDPF: EPUB Accessibility 1.0: Conformance and Discovery Requirements for EPUB Publications: Recommended Specification 5 January 2017.

Accessibility of Non-Web ICT

Guidance on Applying WCAG 2.0 to Non-Web Information and Communications Technologies (WCAG2ICT): W3C Working Group Note 5 September 2013.
Guidance on Applying WCAG 2 to Non-Web Information and Communications Technologies (WCAG2ICT): W3C Working Group Draft Note 02 July 2024.
IBM Corporation: IBM Accessibility Checklist. Version 7.1 of this checklist was released on 23.06.2019.

Evaluation Methods

Website Accessibility Conformance Evaluation Methodology (WCAG-EM) 1.0: W3C Working Group Note 10 July 2014.
See also the WCAG-EM report tool, which supports evaluations that follow WCAG-EM, and the EARL + JSON-LD documentation that describes the tool's output format.
Der BIK BITV-Test. A German evaluation method originally based on WCAG that was updated to EN 301 549 in 2021.
Accessibility testing guide, alphagov / Government Digital Service (UK on GitHub. (Accessed on 04.07.2022.)
Référentiel d'Évaluation de l'Accessibilité Web (RAWeb 1), Portail de l'accessibilité numérique, published on 08.02.2024.
See the announcement RAWeb, un référentiel qui comprend vraiment tout (08.02.2024).
Guide de l'auditeur RGAA 3 by the French government, on GitHub. A PDF version of the Guide de l'auditeur can still be downloaded. This dates from June 2017, roughly a year before the publication of WCAG 2.1 and is therefore partially outdated.
WCAG Audit Discussies in Nederland en Vlaanderen (GitHub). Not actually an evalation method but questions about the interpretation of WCAG as an auditor. The discussion are conducted in issues submitte to a GitHub repository. The site WCAG Audit Discussies in Nederland en Vlaanderen links to outcomes of the discussions on the issues.

Historical Standards and Guidelines

Media Accessibility User Requirements: W3C Working Group Note 03 December 2015, World Wide Web Consortium.
From the abstract: This document presents the accessibility requirements users with disabilities have with respect to audio and video on the web. This document is listed here because there were no new drafts between December 2015 and December 2023.
W3C: Web Content Accessibility Guidelines 1.0: W3C Recommendation 5-May-1999, superseded 18 May 2021
Translations:
- Directives pour l'accessibilité aux contenus Web (version 1.0): W3C Recommendation 5-May-1999.
- Zugänglichkeitsrichtlinien für Web-Inhalte 1.0: Deutsche Übersetzung.
Vanderheiden, Gregg C.; Chisholm, Wendy: Page Author Guidelines - Version 8: Unified Web Site Accessibility Guidelines, Web Accessibility Initiative (W3C WAI), 20.01.1998.
This document was a precursor of the Web Content Accessibility Guidelines 1.0 (5 May 1999) and is listed here for purely historical reasons.
PAS 78: Guide to good practice in commissioning accessible websites, British Standards Institution (BSI). This standard was published in 2006 in replaced with BS 8878:2010.
BS 8878:2010: Web accessibility. Code of practice, British Standards Institution (BSI).
In 2019, this standard was superseded by ISO/IEC 30071-1.