The document that sets out the guidelines against which the accessibility of websites and mobile applications is measured is known as the “Web Content Accessibility Guidelines” (frequently referred to as WCAG).
This document is used as a reference for developing accessible digital projects and auditing the accessibility of existing ones. Consequently, to be included in the document, guidelines must meet two criteria:
- They must address significant access issues that particularly affect people with disabilities (meaning they go beyond the usability issues that affect everyone).
- They must be verifiable, so that compliance can be measured with a high degree of reliability.
The laws regulating sites that are required to be accessible are based on this document.
Something that occasionally causes a bit of confusion is that the guidelines are divided into three levels: A, AA, and AAA. These are cumulative, which means that to achieve Level AA (which is the standard recommendation and the one mentioned by law), all Level A and Level AA guidelines must be met. It is also possible that some may not apply; for instance, those referring to audio and/or video content do not apply if the site does not contain that type of content.
Levels are assigned based on how essential each guideline is, whether it is possible to meet it across different types of sites and content, and whether it is reasonable for content creators to comply with it. Thus, Level A guidelines are minimum requirements that remove basic obstacles; Level AA guidelines are the standard that improves accessibility for a wider range of people; and Level AAA guidelines represent the highest level of exigency, and it is not realistic to expect all types of content to meet them.
If we analyse the guidelines for interactive elements or forms, the expectation of coding knowledge is higher than for guidelines such as the use of images or colours, as it is reasonable to assume that whoever implements interactivity or forms on a website will have sufficient coding skills to meet the criteria.
The levels exist because the rigorous work involved in creating the guidelines focuses not only on how they affect the people who will use the website, but also takes into account the task of implementing them. Although we generally focus on the obligation to comply with certain guidelines, we have access to a broad list of meaningful and measurable criteria, and the levels serve as additional information for their fulfilment.
Fran Rosa, Senior Developer & Advocate specialising in people-first development