[meta] Track progress in ATAG 2.0 conformance

This is going to be a tracker for all issues covering (not just obeying) ATAG 2.0 conformance, sorted by ATAG 2.0 norm.
This tracker should help us achieve the stated goal of WCAG 2.0 and ATAG 2.0 level AA conformity for Drupal core.

Please help adding relevant, preexisting issues to this list, before creating many new issues that no one takes care of and that end up not being manageable!

Section A: Make the authoring tool user interface accessible

A.1. Authoring tool user interfaces must follow applicable accessibility guidelines

A.1.1. Accessible web-based UI

- irrelevant to Drupal

A.2. Editing-views must be perceivable

A.2.1. Make alternative content available to authors

#2034999: [meta] Comply with WCAG 1.1: Text Alternatives →

A.2.2. Editing-view presentation can be programmatically determined (UI)

A.3. Editing-views must be operable

A.3.1. Provide keyboard access to authoring features (UI)

A.3.2. Provide authors with enough time (UI)

A.3.3. Help authors avoid flashing that could cause seizures (UI)

#2036293: [meta] Comply with WCAG guideline 2.3: Seizures →

A.3.4. Enhance navigation and editing via content structure (UI)

A.3.5. Provide text search of the content (UI)

A.3.6. Manage preference settings (UI)

A.3.7. Ensure that previews are at least as accessible as in-market user agents (UI)

A.4. Editing-views must be understandable (UI)

A.4.1. Help authors avoid and correct mistakes (UI)

A.4.2. Document the user interface including all accessibility features (UI)

Section B. Support the production of accessible content

B.1. Fully automatic processes must produce accessible content

B.1.1. Ensure automatically specified content is accessible

B.1.2. Ensure accessibility information is preserved

B.2. Authors must be supported in producing accessible content

B.2.1. Ensure accessible content production is possible

B.2.2. Guide authors to produce accessible content

B.2.3. Assist authors with managing alternative content for non-text content

B.2.4. Assist authors with accessible templates

B.2.5. Assist authors with accessible pre-authored content

B.3. Authors must be supported in improving the accessibility of existing content

B.3.1. Assist authors in checking for accessibility problems

http://quailjs.org/

B.3.2. Assist authors in repairing accessibility problems

B.4. Authoring tools must promoted and integrate their accessibility features

B.4.1. Ensure the availability of features that support the production of accessible content

B.4.2. Ensure that documentation promotes the production of accessible content

(see latest version of Implementing ATAG 2.0)

per module / subsystem:

CKEditor

#1879430: [meta] Find and report any accessibility issue of CKEditor and its Drupal integration →

Views

#1802678: [META] Views: accessibility review →
#1806278: Test whether Views conforms to WCAG 2.0 and ATAG 2.0 →

See also:

#2034915: [meta] Track progress in WCAG 2.0 conformance →