Here we will look at the WCAG2.0 Guidelines level AA. This is the second of three levels of accessibility and in the UK is considered the minimal level for all public sector organisation web services. It will help give most people a reasonable level of access although it will not neceressally give people an equal experience.
The guidelines are based on four principles POUR, see the article Get started with WCAG2.0 for an overview.
Note before you can reach WCAG2.0 Level AA you must first meet all WCAG2.0 Level A, see WCAG2.0 Level A, your guide part 1.
1.2.4 Captions (Live): Captions are provided for all live audio content in synchronized media. This is to offer an alternative text based content that is presented at the same time as the live audio for the benefit of those people who may not be able to hear the audio stream. This may include people with hearing impairments as well as people who may not have any audio device available.
1.2.5 Audio Description (Pre-recorded): Audio description is provided for all pre-recorded video content in synchronized media. This is where you add audio descriptions of any relevant visual content to the video media for the benefit of people who may not be able to see the visual content. Please note this will not address people who have difficulty with both visual and audio content. To address this a textual content such as full transcript will be required.
1.4.3 Contrast (Minimum): The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following:
- Large-scale text (18PT+ or Bold 14PT+) and images of large-scale text have a contrast ratio of at least 3:1;
- Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.
- Text that is part of a logo or brand name has no minimum contrast requirement.
You can use free tools like the webaim colour checker to see if your colour contrast meets the requirements.
1.4.4 Resize text: Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality. This is to allow people to use the text size option of their web browser to increase the text size. It should allow text to be double it’s original size without breaking or making it difficult to read or use.
1.4.5 Images of Text: If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text except for the following:
- The image of text can be visually customized to the user’s requirements;
- A particular presentation of text is essential to the information being conveyed (text that is part of a logo or brand name) are considered essential.
By using textual content instead of text within images, it will allow people to adapt the text into a format that they can use. Where as text within images are not so flexible and may not be accessible to some people. Examples may include people using Braille or people with dyslexia or limited vision.
2.4.5 Multiple Ways: More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process. This may include things like a site map, keyword search or breadcrumb. All can help people find pages within a website more easily.
2.4.6 Headings and Labels: Headings and labels describe topic or purpose. This is about how effective the use of language is to describe the relevant topic or purpose in headings and labels. This will help people quickly identify and understand the various topics and controls available to them. Short, simple, concise and relevant are what will be most effective.
2.4.7 Focus Visible: Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible. This is about showing people where they currently are on a page when using a keyboard or other similar control device. Unlike using a mouse, where you have a pointer to show you, without this pointer, you need other visual indication such as highlighted outlines, change of colour or similar clearly marked visible indicator.
3.1.2 Language of Parts: The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, and words or phrases that have become part of the vernacular of the immediately surrounding text. This is referring to any content that is in any other language other than the default language set for the page. So if the default language is in English but there is a short passage wrote in French, this will need to use mark-up that specifies that it’s in French. The purpose is to help assistive technology such as screen readers, Braille displays and others know the change of language from the default set at the beginning.
3.2.3 Consistent Navigation: Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user. Consistency will help people become familiar more quickly and can greatly enhance the experience for people using assistive technology.
3.2.4 Consistent Identification: Components that have the same functionality within a set of Web pages are identified consistently. If not consistent in the naming of Components across web pages, it can give confusing or conflicting information. Leading to people being frustrated, confused or simply lost.
3.3.3 Error Suggestion: If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content. This is about helping people understand where and what mistakes they may of made. By offering support in this way, it can help people complete tasks without the need for alternative communication. It is best if the error messages are provided in text with clear indication to where the mistake was made.
3.3.4 Error Prevention (Legal, Financial, Data): For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true:
- Submissions are reversible, meaning people can request to undo the change.
- Data entered by the user is checked for input errors and the user is provided an opportunity to correct them. This will give people the chance to see any mistakes and allow them to correct them before making any commitment.
- A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission. This is giving people the chance to look over their information and choices before making a commitment and allowing them to make any changes required.
There are no level AA or AAA guidelines in the last principle, only 2 level A guidelines.