Glossary · Accessibility term
Informative
Informative means for information purposes and not required for conformance, which makes it the exact opposite of normative. It covers whole documents, the techniques and the Understanding pages among them, and it also covers six kinds of material inside WCAG itself. Introductory text, appendices, sections marked non-normative, diagrams, examples and notes are all informative, so a note sitting under a success criterion tells you how W3C reads that rule rather than adding to it. What the word does not mean is optional extra. W3C cautions against anyone requiring its own sufficient techniques, on the grounds that the only thing that should ever be required is meeting the success criteria.
In practice
The label is printed at the top of every Understanding page, so before anybody quotes one at you as a requirement, look at the banner. It says the page is an informative explanation, not required to meet WCAG. The success criterion is the rule and everything written around it is somebody explaining the rule, including W3C.
The operational form of the word is a rule that runs in both directions, and most people only know one half of it. Not using a sufficient technique is not a failure, because there are other ways to pass and the criterion never named one. Working through every sufficient technique listed for your technology does not settle it either, because what has to be true is that the criterion is met, and a technique applied where it does not fit, or in a way nothing supports, has not met anything. So the technique list is neither the test nor the escape from it.
Two details change how a sufficient-technique list should be read. Where techniques are joined by AND, all of them are needed and the list is not a menu. And a technique only counts where the way you are using it is accessibility supported, meaning it works with the assistive technology your readers actually have.
Informative is not a weaker grade of requirement. W3C's advisory material deliberately goes past the criteria and addresses barriers no testable rule covers, which makes some of it the only written guidance that exists for a real problem.
Why it matters
A great many arguments about whether something passes come down to somebody quoting an informative document as though it were the standard, and W3C puts this more strongly than we would dare to. Its own position is that requiring its sufficient techniques is a thing to be cautioned against, because the only thing anybody should require is meeting the success criteria. That sentence is worth having in front of a procurement team. The mistake runs the other way too, though. A team that hears informative and decides the techniques are optional usually ends up failing the criterion those techniques were written to document.
A published failure is still advice
F69 is a documented failure of the resize-text rule. On that same page, the Working Group says it has found many misunderstandings about how to test it and plans to revise it, and that until then content passing the criterion by any of the sufficient routes does not meet the failure. A scanner or an auditor citing a failure is citing advice about the rule, never the rule.
Where this shows up on the site
Related terms
Knowing the word is the easy part.
Find out where your own site stands. The free scan checks 10 pages in a real browser against all 90 supported automated rules, separates 27 best-practice checks from its WCAG findings, and names the rule behind every result.