I’m currently involved in a project to make some of the WCAG guidance more clear. One of the distinctions we’re hoping to clarify is: what’s normative in WCAG?
‘Normative’, meaning something like ‘required to meet the norm’, is a common phrase in (web) specifications. You’ll find it in WCAG, but also in HTML, CSS and many others. Specifications say what we should do (‘do X’), in a way that can be evaluated afterwards (‘was X done?’).
For instance, the normative sentence ‘Web pages have titles that describe topic or purpose’ (from: Page titled) can be evaluated: if a web page has a title and it describes topic or purpose, it’s a pass. Otherwise, it’s a fail.
The opposite of ‘normative’ is ‘informative’, it is something that is not required for conformance to the norm. You may also find it is called ‘non-normative’, ‘not required’ or descriptive in some places.
As an aside, the words ‘may’, ‘must’, ‘must not’, ‘not recommended’, ‘recommended’, ‘should’ and ‘should not’ have special meaning in the context of specifications like WCAG. This meaning is defined in a document called RFC 2119.
What’s normative in WCAG
The part of WCAG that is normative is the main WCAG text itself: the Principles, the Guidelines and the Success Criteria.
What’s not normative in WCAG
Some of the WCAG text is not normative, like the Introduction section. It is marked as such (“This section is non-normative”).
There is also a number of documents to help use WCAG, including Techniques and Understanding documents. These documents are not normative either. They are additional information, context and examples, but not requirements to meet the norm (see 5.1, Interpreting Normative Requirements).
For instance, if you would evaluate whether a website meets the WCAG criteria, what matters for conformance is the text of the relevant criterion. The text in a Technique or Understanding document can help understand the intents and purposes of the norm, but it is not the norm. You don’t need to follow any specific Technique to be conformant.
The norm is the core
In most standards, the part that has become the norm was discussed and tweaked by many people over an extended time. Working Groups often spend years ensuring a wide variety of people was consulted and many views heard. There are likely many other things that could have made it in, but this was the text on which the Working Group reached consensus: it was supported by a substantial part of the group, and no formal objection was registered.
That leads me to an important point regarding WCAG: the normative part is the minimum to make your site work for users with disabilities. There are lots of best practices outside WCAG scope that benefit actual people–absolutely do find and use those!
In WCAG, the main text is normative, which means it is required to meet the standard. Other texts like Techniques, Understanding documents and ARIA Authoring Practices are not, they provide useful context, examples, background information and more.