What a CMS or editor owes the people who write in it

ATAG 2.0, EN 301 549 11.8 and Section 508 504 ask an authoring tool to work for authors with disabilities and to help every author publish accessible content.

In short: ATAG 2.0 asks two things of a tool people write web content in: Part A, that authors with disabilities can use it, and Part B, that it helps every author make content that meets WCAG 2.0, by prompting, checking, suggesting repairs and keeping accessibility information. A tool can ask for alt text and refuse a file name, but only the author knows what the image is there to show.

When you need this

A marketplace lets sellers publish listings. The listing tool has a photo upload, a description box with Bold, Heading and list buttons, an "Improve with AI" button that rewrites the description, and an add-on that writes an AI description into each photo's alt text on upload. The site's WCAG audit covered the pages shoppers read, and it passed.

A large client now wants its own staff to publish through the same tool, and its contract asks the listing tool to meet EN 301 549 11.8 and to follow ATAG 2.0. The product owner asks what that adds to a site that already passes WCAG.

When software counts as an authoring tool

ATAG 2.0 defines an authoring tool as any application "that can be used by authors (alone or collaboratively) to create or modify web content for use by other people". Section 508 defines it the same way without the word "web", and EN 301 549 (3.1) more briefly, as "software that can be used to create or modify content". In ATAG and Section 508, the test is the last part: content that someone else reads.

Authoring tools, in ATAG's own examples: WYSIWYG and source code editors, "Save as HTML" features, content management systems, blogs, wikis and forums, email clients that send HTML, multimedia tools, and software that builds pages from templates or wizards.
Also authoring tools, by the definition: a marketplace's listing form, a profile's About box, a review box. Each publishes what one person writes for others to read.
Not authoring tools, in ATAG's examples: an e-commerce order form, whose purpose "is to order a product, not communicate with other people"; a personal portal only its owner sees; a stand-alone accessibility checker that repairs nothing.

WCAG still applies to the pages of a tool that isn't an authoring tool. ATAG adds the second question: what the tool does for the content its authors make.

Part A: authors with disabilities can use the tool

Part A is about the tool's own screens: menus, toolbars, dialogs, settings, documentation, and the editing view itself.

Principle	What it asks, with some of its criteria	Example
A.1 Follow accessibility guidelines	A.1.1.1: a web-based interface meets the WCAG 2.0 success criteria. A.1.2: a non-web one follows its platform's guidelines and exposes information through platform accessibility services	A description box with no name: rich text editors announced without their label
A.2 Editing views are perceivable	A.2.1.1: text alternatives in the content can be programmatically determined while editing. A.2.2.1: status indicators such as spelling errors can be too	—
A.3 Editing views are operable	A.3.1.1 and A.3.1.2: everything works from a keyboard, with no traps. A.3.2.1: no session time limit, or edits are saved before it. A.3.5.1: text search of the content (AA)	A photo box that takes only dropped files: file upload drop zones with no button to choose files
A.4 Editing views are understandable	A.4.1.1: every authoring action can be undone, or the tool asks before it goes ahead. A.4.2.1: the accessibility features are documented	A rewrite saved over the author's words: AI rewrite buttons that replace text with no preview or undo

Part A's notes draw two lines. A problem in the content being edited, such as an image in it with no text alternative, is not a fault in the tool's interface. And Part A covers the tool as its developer provides it, not plug-ins or settings someone else changes.

A.1.1.1 is WCAG 2.0, so it doesn't reach criteria added later. The rich text editor guide fails 2.5.3 Label in Name as well as 4.1.2 and 1.3.1. 2.5.3 came with WCAG 2.1, so it is outside A.1.1.1, but a web-based tool's own screens are web pages under EN 301 549, and its clause 9 includes it.

Part B: the tool helps every author make accessible content

Part B is about the content, whoever the author is.

Guideline	What it asks	Example
B.1.1 Content the tool generates is accessible	B.1.1.1: what it generates after the session, such as site-wide templates, can be accessible. B.1.1.2: what it generates during one is accessible, or the author is prompted, or a check runs or is suggested	—
B.1.2 Accessibility information is preserved	Through transformations (B.1.2.1), copy and paste within the tool (B.1.2.2), optimisations (B.1.2.3), and text alternatives (B.1.2.4)	A video encoder that drops the captions: captions stuck in one style, or lost when video is converted
B.2.1 and B.2.2 Accessible content is possible, and authors are guided to it	B.2.2.1: accessible options are at least as prominent as the others. B.2.2.2: wherever properties can be set, the accessibility ones can be too	A Heading button as easy to reach as Bold; headings that don't match the page's sections shows the page side
B.2.3 Alternative content	B.2.3.1: authors can edit the text alternatives. B.2.3.2: rules for any text alternative the tool fills in itself	Image uploads that never ask for alt text, AI alt text that misses or misreads what a photo shows
B.2.4 and B.2.5 Templates and pre-authored content	B.2.4.1: accessible templates for a range of uses. B.2.4.2: the selection shows which are accessible (AA)	—
B.3.1 and B.3.2 Checking and repair	B.3.1.1: where authors can break a WCAG criterion, the tool checks it. B.3.2.1: where a check finds a failure, the tool suggests a repair	—
B.4.1 and B.4.2 The features are on and documented	B.4.1.1: accessible content support features are on by default. B.4.2.1: the documentation's examples are accessible	—

What the tool can do on its own, and what needs the author

ATAG's glossary names 3 kinds of repair: manual, where the tool gives instructions and the author makes the repair; semi-automated repair, where "authors' input or judgment is still required to complete the repair"; and automated, with no author input. Implementing ATAG 2.0, the informative companion, says semi-automated repair "is usually appropriate for corrections of a semantic nature", and automated repair for those "of a syntactic or repetitive nature". The same split runs through the whole job.

Task	The tool can	Only the author can
Alt text	Prompt for it when a photo is added; refuse generic or irrelevant strings such as "image" or the file name (B.2.3.2 a); offer a draft from image recognition, to accept, change or reject (B.2.3.2 b)	Say what the photo is there to show, or that it is decorative
Headings and lists	Offer real heading and list buttons as prominently as Bold (B.2.2.1); keep them through paste and conversion (B.1.2)	Decide which line is a heading
Markup the tool writes itself	Make it accessible without asking, such as a page's language or a form's labels in a template (B.1.1)	Nothing
Captions	Carry the caption track through conversion (B.1.2.1); offer a speech recognition draft to correct	Correct the words and name the speakers
Checking	Find what a rule can, such as an image with no alt attribute (B.3.1.1); give instructions for the checks a person decides (B.3.1.2)	Judge whether alt text that exists is right

So the tool's part is to ask, at the right moment, and to keep what the author gave. A prompt is any request the tool starts for a decision or information, a dialog or an underline. Where the tool fills in a text alternative itself, B.2.3.2 decides by the authoring session: during it, the author must be able to accept, modify or reject the text before it goes into the content; after it, the text can go in, but must be marked for the author in their next session, again to accept, modify or reject. Implementing ATAG 2.0 counts image processing as a relevant source for a suggestion, "while not as dependable as a human describer".

Levels, and why ATAG points at WCAG 2.0

63 success criteria: 31 in Part A and 32 in Part B, at Level A, AA or AAA, the model ATAG shares with WCAG.
13 marked "(WCAG)", such as A.1.1.1 and B.3.1.1: their level follows the WCAG level the content meets: "Level A to meet WCAG 2.0 Level A success criteria; Level AA to meet WCAG 2.0 Level A and AA success criteria".
Conformance: Level A is every applicable Level A criterion, AA adds the AA ones, AAA is all. A tool that needs other tools to make a complete authoring system can claim partial conformance as a process component, and one held back by its platform can claim partial conformance for platform limitations.
Claims are optional. A claim gives the date, the ATAG version, the level, the tool and its version, the platforms, the web content technologies produced, and a Yes, No or Not Applicable for every criterion.
Why WCAG 2.0: "At the time of publishing, WCAG 2.0 [WCAG20] is the current W3C Recommendation", so ATAG's "accessible content" is content that would conform to WCAG 2.0. ATAG hasn't been revised since 24 September 2015, so its references to WCAG are still 2.0. It also leaves out WCAG's accessibility-supported requirement, because a tool runs in many environments, and so it speaks of "meeting WCAG 2.0 success criteria", not conformance.

The WCAG version the content itself must meet comes from the law or contract the site is under. EN 301 549 V3.2.1 11.8.2 points at its own clause 9, WCAG 2.1, and V4.1.1 moves authoring tools to 5.10 with clauses 9 to 11 aligned to WCAG 2.2. Section 508 504.2 points at WCAG 2.0 Level AA.

Worked example

The listing tool, against the three documents:

What the tool does	What it meets or fails	Result
The upload publishes each photo with its file name, IMG_2041.jpg, as the alt text, and never asks	ATAG B.2.3.2 (a) and B.1.1.2; EN 301 549 11.8.2; Section 508 504.3	Fail: image uploads that never ask for alt text
The add-on writes an AI description into the alt text on upload, and nobody sees it before the listing goes live	ATAG B.2.3.2 (b)	Fail: AI alt text that misses or misreads what a photo shows
The description box is a contenteditable div with no name	ATAG A.1.1.1 (WCAG 2.0 1.3.1 and 4.1.2); EN 301 549 9.1.3.1, 9.4.1.2 and 9.2.5.3 for the tool's own page	Fail: rich text editors announced without their label
"Improve with AI" saves over the description, with no preview and no undo	ATAG A.4.1.1	Fail: AI rewrite buttons that replace text with no preview or undo
The Heading and list buttons sit beside Bold, the same size	ATAG B.2.2.1	Pass
The checker before publishing finds a photo with no alt text and opens its description field	ATAG B.3.1.1 and B.3.2.1; EN 301 549 11.8.4	Pass

Result: the shoppers' pages pass WCAG, and the tool fails 4 times. 2 failures are Part B: the tool decided what a photo shows, once with a file name and once with an AI guess, where B.2.3.2 leaves that decision to the seller. 2 are Part A: a seller using a screen reader can't tell which box they are writing in, and anyone can lose their own words to one press. Each fix is in its guide; together they make the tool ask the seller at upload, show the AI text as a draft to accept, change or reject, name the description box, and keep the old text until the seller chooses.

Common mistakes

Auditing only the published pages. Part A is the tool's own screens: a photo box only a mouse can use fails the authors, whatever the listing looks like afterwards. See file upload drop zones with no button to choose files.
Filling the alt text with the file name or "image" so the checker passes. B.2.3.2 (a) rules out generic and irrelevant strings, and 1.1.1 still fails on the published page. The fix is in image uploads that never ask for alt text.
Publishing machine descriptions unread. B.2.3.2 allows a suggestion from image processing only if the author can accept, change or reject it first, or, after the session, sees it marked next time. See AI alt text that misses or misreads what a photo shows.
Making alt text compulsory with no way out. Section 508 504.2 asks tools to "permit authors the option of overriding information required for accessibility", and B.2.3.1 exempts content known to be decoration. A seller needs a way to mark a photo as decorative.
Shipping the checker switched off. ATAG B.4.1.1, Level A, asks for accessible content support features to be on by default. Section 508 doesn't: the Access Board judged that "overly prescriptive".
Claiming ATAG for WCAG 2.2 content. ATAG's "(WCAG)" criteria are WCAG 2.0. Say which WCAG version the content meets separately, from the site's own test.
Adding a checker with no repair suggestions. Where a check finds a failure, B.3.2.1 and EN 301 549 11.8.4 ask for a repair suggestion beside it. An instruction the author carries out is enough: ATAG's note says manual repair is the minimum.

What the standard says

ATAG 2.0, B.2.3.2 Automating Repair of Text Alternatives (required, Level A): the tool doesn't attempt to repair text alternatives, or "Generic strings (e.g. "image") and irrelevant strings (e.g. the file name, file format) are not used as text alternatives", and in-session repairs give authors "the opportunity to accept, modify, or reject the repair attempt prior to insertion".
ATAG 2.0, A.4.1.1 Content Changes Reversible (Minimum) (required, Level A): "All authoring actions are either reversible or the authoring tool requires author confirmation to proceed."
ATAG 2.0, B.3.2.1 Repair Assistance (required, level by WCAG level): "If checking (see Success Criterion B.3.1.1) can detect that a WCAG 2.0 success criterion is not met, then repair suggestion(s) are provided". Its note: "manual repair is the minimum requirement".
Implementing ATAG 2.0 (advice): the intent of B.2.3.2 is "to prevent the production of text alternatives that are not useful to end users because they have not been approved by authors and/or are derived from improper sources."
EN 301 549 V3.2.1, 11.8 (required): 11.8.1 applies 11.8.2 to 11.8.5 "to the extent that information required for accessibility is supported by the format"; 11.8.2, the tool "shall enable and guide the production of content that conforms to clauses 9 (Web content) or 10 (Non-Web content)"; 11.8.3, accessibility information is preserved in restructuring and re-coding transformations; 11.8.4, repair suggestions where checking finds a failure; 11.8.5, where there are templates, at least one accessible one, "identified as such". 11.8.0, which is informative, points to ATAG 2.0 for "those who want to go beyond these requirements". In V4.1.1 the same five are 5.10.1 to 5.10.5, each opening "Where ICT is, or includes, authoring tool functionality", and note 2 to 5.10.4 encourages automated and semi-automated repair "with author review".
Section 508, 504 (required): 504.1 applies 504 "to the extent that information required for accessibility is supported by the destination format"; 504.2, a mode of operation to create content that conforms to WCAG 2.0 Level A and AA, with the option of overriding; 504.2.1, preservation through format conversion; 504.2.2, PDF/UA-1 export where a tool exports PDF 1.7; 504.3, a mode that prompts authors; 504.4, templates for a range of uses.

How they differ: ATAG is the only one with a full Part A, since EN 301 549 and Section 508 cover a tool's own screens through their web and software requirements. The Access Board says it relied on ATAG 2.0 for 504 but declined to reference it, because, in its words, ATAG 2.0 "is very narrowly focused on Web content and is very prescriptive", and is little used by federal agencies. EN 301 549 asks the tool to "enable and guide"; Section 508 asks for a "mode of operation" that prompts.

Limits

ATAG 2.0 conformance is voluntary unless a contract or policy names it, and nothing here says which law covers a given tool; that is for the client and a lawyer. Whether a borderline feature, such as a comment box or a chat, is an authoring tool is the tester's call against the definition, written down with the reason. ATAG covers the tool as its developer ships it, not plug-ins or settings changed afterwards, so a CMS's claim doesn't cover the add-ons a site installs. Live authoring, such as a presentation published as it happens, is in Implementing ATAG 2.0's Appendix E, not here. The rest of EN 301 549 is on what EN 301 549 asks of a website beyond WCAG. Test the tool with the authors who use it, and the content with the people who read it.

Terms

authoring tool: Software, web-based or not, that people use alone or together to create or modify web content for use by other people (ATAG 2.0 glossary).
prompt: Any request the authoring tool starts for a decision or a piece of information from authors, from a dialog to an underline (ATAG 2.0 glossary).
semi-automated repair: A repair the tool carries out in part, with the author's input or judgment needed to finish it (ATAG 2.0 glossary).
authoring session: The time in which an author can edit the content; it ends when they close or publish it, or the tool hands editing to someone else (ATAG 2.0 glossary).

Sources and guides

Guides that show it

This page explains a practice, with recreated examples. It is not legal advice, and it is not a finding about a named client.