WCAG.
WCAG is the international standard published by the W3C that defines the accessibility of web content through testable success criteria.
The word “guidelines” in the name misleads: the document is not a list of suggestions but a standard whose every item can be tested one by one. That is why accessibility stopped being a matter of opinion and became a measurable condition.
The structure has three layers. At the top are four principles: perceivable, operable, understandable and robust. Under each principle sit guidelines, and under those the success criteria. Conformance is assessed on the success criteria alone; the principles and guidelines are not binding.
Every success criterion belongs to one of three conformance levels, and the levels build on one another: a page conforming to AA also conforms to A. The distinction rests on consequence rather than difficulty — when level A criteria are unmet, the content becomes entirely inaccessible to some users.
The current version is WCAG 2.2, published on 5 October 2023. It added nine new success criteria, removed one (parsing) and remained backward compatible with WCAG 2.1. The Turkish Presidential Circular of 2025 takes level A of this version as its reference; level A contains 31 success criteria.
- A — the baseline, 31 criteria. When unmet, content is inaccessible to some users.
- AA — the de facto standard. Contrast, focus visibility and target size begin at this level.
- AAA — extended. The W3C does not recommend targeting it for a whole site; some criteria are not realistic for every kind of content.
The standard is used together with three families of documents: the normative guidelines themselves, the “understanding” documents explaining the intent of each criterion, and the “techniques” documents showing ways to implement them with code examples. The most useful entry point for daily work is the quick reference, which can be filtered by level and technology.
The W3C is working on WCAG 3.0 in parallel, but it will move from the binary pass-fail model to a scored one and will stay in draft for a long time. Investment in 2.2 today keeps its validity for the near future.
There is a rule to observe when making a conformance claim: the level has to hold for the WHOLE of the scope declared. If a single page has an AA violation, that scope does not conform to AA. Keeping the scope narrow and genuinely meeting it is therefore both more honest and more defensible than keeping it wide and meeting it partly.
Because there is no official Turkish translation of the standard, the terms circulate in sources with different renderings. Fixing a glossary within the organisation prevents confusion in audit correspondence.