Web Accessibility: Definitions and Acronyms

An overview of the many definitions and acronyms pertaining to web accessibility and why its important to be familiar with them.

Initially, learning about web accessibility, its policies, and its guidelines can seem daunting, but taking the time to learn and understand the basics is well worth the effort. In order to have informed discussions and make informed decisions, web accessibility is an area in which all website owners and web professionals need to have foundational knowledge. In some cases, failure to follow web content accessibility guidelines can become a legal matter.

For a website to be accessible, web accessibility must be considered at every stage of the project process; starting with initial planning and then continuing through project discovery, user experience testing, design, and development. 

At Lullabot, for example, we consider web-accessible practices throughout our work in a variety of ways. A few examples: our designers test contrast ratios while they are creating new designs. Our developers include and verify aria labels where needed, semantic tags are used while implementing markup, and new features work using keyboard navigation and voice over.

A firm commitment to designing, building, and maintaining accessible websites begins with understanding the basics. The general web accessibility information outlined below will help you start your journey of attaining accessibility compliance in your web projects.

So, what are the W3C and WCAG?

W3C is the acronym for World Wide Web Consortium. The World Wide Web Consortium "is an international community where Member organizations, a full-time staff, and the public work together to develop Web standards. Led by Web inventor and Director Tim Berners-Lee and CEO Jeffrey Jaffe, W3C's mission is to lead the Web to its full potential. "In short, the W3C as an organization is responsible for developing the standards and guidelines that, when followed, help make the Web accessible to everyone.

The W3C provides Web Content Accessibility Guidelines (WCAG), but as an entity, it does not enforce them. Governments choose if and how to use the guidelines in their jurisdiction. Since compliance requirements vary by country, the W3 maintains a useful list of governmental policies that can be searched by country.

Web Content Accessibility Guidelines

WCAG, WCAG 2.0, and WCAG 2.1

WCAG is the acronym for Web Content Accessibility Guidelines. WCAG 2.0 and WCAG 2.1 are versions of those guidelines. On December 11, 2008, the W3C published WCAG 2.0. Ten years later, on June 5, 2018, the W3C published WCAG 2.1.

Each guideline has different levels of conformance: A, AA, and AAA, with the last being the highest level of conformance. These are structured to cascade from higher to lower. If you conform to a guideline at the AA level, it is assumed you conform at the A level as well. Likewise, if you conform at the AAA level, then you also meet the standards for both the AA and A levels.

When companies are striving to meet WCAG 2.0 or WCAG 2.1 standards, this usually means that they are aiming for A and AA compliance. Companies with a lot of multimedia might aim for AAA.


Silver, the next version of WCAG, is currently in progress. Based on the major milestones the working group has outlined, they are targeting a 2021 or 2022 release of their recommendations. This project's official name is now W3C Accessibility Guidelines (WCAG) 3.0.

Web content accessibility compliance in the United States (US)

In the United States (US), the Federal Government has written several laws based on the WCAG guidelines. While this post should not serve as legal advice, we hope it clarifies the responsibilities that organizations in the US - and their development teams - share with the site owners to ensure compliance. You may have heard people mention Section 508 or Section 504. These laws require specific groups to adhere to WCAG guidelines.

Web content accessibility requirements for US federal agencies, or US organizations that receive federal funding

The Rehabilitation Act of 1973 contains a few specific sections detailing the responsibilities of government agencies and organizations that receive federal funding related to technology. Section 508 applies to government agencies, while Section 504 applies to organizations that receive federal funding.

Government Agencies: Section 508 of the Rehabilitation Act

Section 508 of the Rehabilitation Act is a Federal law of the United States Government. The law "applies to all Federal agencies when they develop, procure, maintain, or use electronic and information technology. Federal agencies must ensure that this technology is accessible to employees and members of the public with disabilities to the extent it does not pose an 'undue burden.' "

In short, any US Federal department or agency website must comply with Section 508. The revised 508 Standards are based on WCAG 2.0 compliance - the version from 2008 mentioned above - so all US Federal department and agency websites must pass WCAG 2.0 guidelines.

To clarify for organizations in the private sector that receive Federal funds, "Section 508 applies to [US] Federal departments and agencies… it does not regulate the private sector and does not apply to recipients of Federal funds."

If your organization is in the private sector and receives funding from the US Federal Government, Section 508 of the Rehabilitation Act does not apply to your website.

Organizations that receive federal funding: Section 504 of the Rehabilitation Act

Section 504 of the Rehabilitation Act requires you to have an accessible website if your organization receives Federal assistance. "Section 504 prohibits discrimination based on disability by federal agencies and recipients of federal assistance. In this instance, accessibility applies to facilities and communications such as websites."

Web applications and software used for communication: 21st Century Communications and Video Accessibility Act (CVAA)

If your organization creates web applications or software used for communication or conferencing, you need to comply with the 21st Century Communications and Video Accessibility Act (CVAA). As its name suggests, this act aims to update accessibility laws to reflect modern technology and the ways we use the internet today.

The CVAA "Requires advanced communications services and products to be accessible by people with disabilities. Advanced communications services are defined as (1) interconnected voice over Internet protocol (VoIP) service; (2) non-interconnected VoIP service; (3) electronic messaging service; and (4) interoperable video conferencing service. This includes, for example, text messaging, e-mail, instant messaging, and video communications."

Web Accessibility and the Americans with Disabilities Act (ADA)

If you are not part of a government organization, nor an organization that receives federal funding, then Sections 508 and 504 don't apply to you. Instead, your web accessibility requirements may be driven by the Americans with Disabilities Act (ADA). "The Department of Justice (DOJ) says that ADA requires any person, business, or organization covered under the Act to communicate effectively about their programs, services, and activities. This includes information provided through your website."

ADA requirements apply to, among other cases, "places of public accommodations." These are businesses that are generally open to the public. The ADA defines 12 categories of these businesses, including schools, recreation, offices, and medical buildings. Ecommerce websites and public mobile applications fall under this part of the ADA - Title III.

The tricky thing about the ADA relative to web accessibility is that the US government has unsuccessfully proposed and withdrawn several rule-making attempts to address website accessibility for public websites since 2010. 

At the time of this writing, there are no official web accessibility guidelines for businesses to follow to comply with the ADA. Without clear guidelines in place, the ambiguity around web accessibility requirements for public websites leaves businesses potentially exposed to legal liability.

General web accessibility recommendations

Even if your organization does not legally need to comply with US laws or the laws in your organization's country, your site, and the sites you build and maintain should comply with WCAG 2.0. Doing so demonstrates your commitment to providing a high-quality experience for all of your site visitors. 

Adhering to WCAG 2.0 is one of many ways you can help people using your website or web application get the information they need and achieve their goals. Compliance is crucial, especially today where, due to social distancing measures internationally, many critical services are only available online.

If your site or application already meets WCAG 2.0, you are in an excellent position to prepare for Silver, and your team can start to address the standards added in WCAG 2.1.

It is important to note that 2.1 has backward compatibility with 2.0. According to the W3C, "WCAG 2.0 and WCAG 2.1 are both existing standards. WCAG 2.1 does not deprecate or supersede WCAG 2.0. W3C encourages you to use the most recent version of WCAG when developing or updating content or accessibility policies."

We consider web content accessibility a vital aspect of the work that we do for our clients. This work is critical in some sectors for liability reasons, like government websites being required to comply with Section 508 of the Rehabilitation Act. It also helps improve the basic success metrics of a website, as no business wants to set up barriers for potential customers. Ultimately, ensuring that your website is accessible creates a more inclusive web experience for everyone.

Published in:

Get in touch with us

Tell us about your project or drop us a line. We'd love to hear from you!