Incomplete draft: This document is an experimental editor's copy that has no official standing and is incomplete. Particularly, the section WCAG 2.0 and MWBP Together is only an outline; WCAG 1.0 to MWBP is only partly filled out. It is subject to major changes and is therefore not intended for implementation. It is provided for review and feedback only. Please send feedback to public-bpwg-comments@w3.org (archive).
This page is part of a suite of related documents. Please refer to the “How to Use These Documents” section for more information.
Comment: Reviewers please bear in mind. This page is for those who have done MWBP and are moving to WCAG 2.0. It answers the two questions “I've done MWBP, how much of WCAG have I already achieved?” and “I'm thinking of doing a bit of WCAG, but is it really justified for my mobile users?”. It therefore works through all the MWBPs and then the WCAG SCs.
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Comment: Reviewers please bear in mind. In this section, the thinking is “I've done MWBP and I'm thinking about now doing WCAG 2.0. I'm more aware of the importance of mobile users. I won't necessarily do all of the WCAG SCs, but might do some if the effort is justified. I want to understand the mobile benefits, if any, of each SC.” For each SC, it gives the mobile benefits (ie, WCAG mapped to MWBP). For each SC we explain why it is a good thing for helping mobile users.
How does it especially help mobile users? WCAG requires a text equivalent for all non-text content, including images. This enables users in the mobile context to read content without downloading images.
How does it especially help mobile users? Mobile devices are often used in situations with significant background noise that makes it difficult to hear the audio track of multimedia content. It public places it may be socially unacceptable to listen to the soundtrack. Captions enable the user to understand the multimedia content in these situations.
How does it especially help mobile users? Unlikely to provide any additional benefit (if audio description is supported by device, might conceivably help with understanding video on small screen)
How does it especially help mobile users? Refer to SC 1.2.1 Captions (Prerecorded).
How does it especially help mobile users? Refer to 1.2.2 Audio Description or Full Text Alternative in this document.
How does it especially help mobile users? Refer to SC 1.2.2 Audio Description or Full Text Alternative in this document.
How does it especially help mobile users? Refer to SC 1.2.2 Audio Description or Full Text Alternative in this document.
How does it especially help mobile users? It allows change and transformation of content in a more flexible way to suit each device.
How does it especially help mobile users? Many mobile devices have monochrome screens, often do not have good color contrast and are often used in less-than-ideal lighting conditions, and so like non-visual users or those with colour perception deficit they may be unable to percieve information conveyed by colour. This success criterion ensures that users who cannot perceive colour correctly for whatever reason will be able to understand and operate the content.
How does it especially help mobile users? Mobile devices may have monochrome screens. Users in a mobile context may view the screen in unfavorable lighting conditions. Adequate color contrast will also help these users.
How does it especially help mobile users? Providing options within the content to switch between layouts that use a variety of font sizes may make for a better experience for users with small screens.
How does it especially help mobile users? Text is more easily adapted to suit the diverse needs of different devices.
How does it especially help mobile users? Refer to success criterion 1.4.3 Contrast (Minimum).
How does it especially help mobile users? Flexibility of presentation helps to ensure that adapted content will be easier to read.
Does it give me MWBP compliance?: No.
Back to list of WCAG 2.0 checkpoints
How does it especially help mobile users? Refer to SC 1.4.5 Images of Text (Limited).
How does it especially help mobile users? Mobile devices typically lack a pointing device and therefore this success criterion benefits the typical user regardless of disability.
How does it especially help mobile users? Mobile users typically navigate using the keypad. Becoming trapped by any component on a page would make it impossible to use the content.
How does it especially help mobile users? The description under 2.1.1 Keyboard is applicable.
How does it especially help mobile users? Content that moves, scrolls or auto-updates may be difficult to see with the reduced size of the mobile viewport. Blinking text may be especially difficult to see on the small screen and in poor lighting conditions.
How does it especially help mobile users? Mobile users typically navigate using the keypad. This can result in a large number of keystrokes to reach the main content of a page, especially if it is preceded by extensive navigation menus or lists of links. This SC also helps users skip large blocks of navigation links at the top of a page, a problem described in NAVBAR.
How does it especially help mobile users? Like users with no vision or limited field of vision, or cognitive disability, mobile users with small screens may have difficulty scanning and summarizing the overall content of a page. Perhaps the most useful item of metadata for a page is a descriptive page title, to provide a quick description of the content of a page.
How does it especially help mobile users? Mobile users are unlikely to have a pointing device so keypad is the primary means of navigation, making focus order especially important.
How does it especially help mobile users? Users of mobile devices may suffer undue delay and cost as a result of following links
due to network charges and device limitations, so it is important to inform them of the purpose of each link.
How does it especially help mobile users? No added benefit.
How does it especially help mobile users? Mobile device users typically navigate with the keypad, so if supported, this would make for easier navigation on small displays with poor visibility.
How does it especially help mobile users? Refer to 2.4.4 Link Purpose (In Context). Refer to “Link text not descriptive” in Summary of Experience of Content Features by Users section.
How does it especially help mobile users? Section headings allow ...easier adaptation of content where it needs to be divided into several pages, as well as potentially facilitating access to the sections of the document that a user is interested in
.
How does it especially help mobile users? Change of user agent: Using a mobile device, launching a new application to render content is especially heavy on processor usage and battery life and should be avoided unless the user has requested it. Change of viewport: Many mobile devices cannot support more than one window and consequently, attempting to open one will have unpredictable results
. Even where mobile devices do support multiple windows, their use is especially problematic. Opening new windows when an element receives focus is especially difficult for the mobile user. Change of focus: Navigation may be especially difficult with a reduced keyboard, and the reduced viewport of the mobile device may lead to the visual user becoming disoriented. Change of content: Auto-refreshing pages ... In a mobile environment they may expose the user to undue cost as a result of such a page being left open or put unnoticed into the background.
also While redirection is a commonly employed mechanism, it must be remembered that redirection usually requires a round-trip to the browser. This adds to delay on slow links...
How does it especially help mobile users? In much the same way as 3.2.1 On Focus.
How does it especially help mobile users? In much the same way as 3.2.1 On Focus.
How does it especially help mobile users? Content adaptation and small screens may result in the visual relationship between labels and controls becoming lost. An explicit association enables the user agent to render them as intended.
How does it especially help mobile users? Mobile user agents are very diverse and it is not possible to be sure that they will behave as expected if invalid markup is used.
How does it especially help mobile users? Similar to the benefit described for 3.3.2 Labels or Instructions but applicable to all user interface components. When the name, role, value, state, and properties is defined this potentially enables reformatting and transformation for the mobile context.
Comment: Reviewers please bear this in mind: In this section, the thinking is “I've done MWBP and I'm thinking about now doing WCAG 2.0. I need to know how much work is involved, so first I want to know how much I have already achieved.” So for each BP we explain how much it helps towards compliance with WCAG.
Below is a list of the BPs described in detail in this section. Each name is a link to the detailed description that follows.
The following BPs are believed to have no added accessibility benefit and no relation to any WCAG provision, and are listed below for completeness:
Does it help meet any WCAG 2.0 success criteria? No, but it corresponds to an advisory technique for SC 2.4.1 Bypass Blocks.
Does it help meet any WCAG 2.0 success criteria? Possibly.
A related success criterion 3.2.5, “Change on Request” requires that refresh be started only by user request, but this BP concerns using auto-refresh started automatically and stopped by user request. If auto-refresh is used compliance is not necessarily achieved. However, if auto-refresh is not used at all, this does ensure compliance with the success criterion.
Refer to 3.2.5 Change on Request, coverage at level AAA.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? Partially. It helps with meeting 1.4.3 Contrast (Minimum) and 1.4.6 Contrast (Enhanced) as described below under COLOR_CONTRAST.
Refer to 1.4.3 Contrast (Minimum), coverage at level AA and 1.4.6 Contrast (Enhanced), coverage at level AAA.
Does it help meet any WCAG 2.0 success criteria? No.
How does it enhance accessibility to users with disabilities?: Putting the main content first helps keyboard-only users whether in a mobile context or not. It may also help users with cognitive disabilities who have difficulty locating the central information in a page full of navigation links. Users who can only read part of the page at a time, and who tend to start at the beginning, such as those using screen readers or screen magnifiers benefit from this BP.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? Possibly.
WCAG success criterion 3.1.5 Reading Level is related but it concerns a different aspect of language comprehension. WCAG is concerned with a user's reading ability, while this BP is concerned with reading difficulty due to context of use (for example, small screen, distracting environnment, lack of time).
Refer to 3.1.5 Reading Level, coverage at level AAA.
Does it help meet any WCAG 2.0 success criteria? Possibly.
However, the BP is concerned with unfavorable ambient light and the ability of devices to display contrasting color at all, while users may have color blindness and color perception deficits, which may lead to different results. Using the more precise criteria given in WCAG 2.0 it may help ensure compliance with 1.4.3 Contrast (Minimum) and 1.4.6 Contrast (Enhanced). Note that WCAG 2.0 suggests a Contrast Ratio and the size of text to which the ratio applies.
Refer to 1.4.3 Contrast (Minimum), coverage at level AA and 1.4.6 Contrast (Enhanced), coverage at level AAA.
Does it help meet any WCAG 2.0 success criteria? Partially.
It meets one of the sufficient techniques for 4.1.2 Name, Role, Value.
Refer to 4.1.2 Name, Role, Value, coverage at level A.
Tip: Avoid nesting a control inside a label element as this is not supported in an accessible way by most user agents.
Does it help meet any WCAG 2.0 success criteria? No, but it is the subject of an advisory technique for 1.3.1, Info and Relationships, “Positioning labels to maximize predictability of relationships”.
Tip: It is much better to use explicitly associated labels (refer to CONTROL_LABELLING).
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? Partially.
It covers some of the sufficient techniques for 1.3.1, Info and Relationships.
Refer to 1.3.1, Info and Relationships, coverage at level A.
It is not the intent of the BP to discourage the use of image maps.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? Yes, this BP ensures compliance with success criteria 2.4.4 Link Purpose (In Context) and 2.4.9, Link Purpose (Link Only).
Refer to 2.4.4 Link Purpose (In Context), coverage at level A and 2.4.9 Link Purpose (Link Only), coverage at level AAA.
Does it help meet any WCAG 2.0 success criteria? Yes, this BP ensures compliance with 1.4.4 Resize text.
Refer to 1.4.4 Resize text, coverage at level AA
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? Partially.
It goes some way to ensuring compliance with 3.2.3 Consistent Navigation, although WCAG is more detailed and specific (“same relative order”) than the MWBP (“same navigation”).
Refer to 3.2.3 Consistent Navigation, coverage at level AA.
Does it help meet any WCAG 2.0 success criteria? Possibly, partially.
Where frames are not used, there is no to identify them as required by 4.1.2 Name, Role, Value.
Refer to 4.1.2 Name, Role, Value, coverage at level A.
Does it help meet any WCAG 2.0 success criteria? Yes, it ensures compliance with success criterion 1.1.1 Non-text Content.
Refer to 1.1.1 Non-text Content, coverage at level A
Tip: As stated in the BP, if the user agent is not known to support the longdesc attribute of the img element (and additionally, until assistive technology is known to support it adequately), do not rely on it. If an extended description is necessary, provide in addition a separate [D] link adjacent to the image.
Does it help meet any WCAG 2.0 success criteria? Possibly.
When scripting is not used or is redundant, 2.1.1 Keyboard and 2.1.3 Keyboard (No Exception) do not apply.
Refer to 2.1.1 Keyboard, coverage at level A and
Refer to 2.1.3 Keyboard (No Exception), coverage at level AAA.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? Possibly.
Providing a page title may ensure compliance with 2.4.2 Page Titled. However, the accessibility techniques are more detailed, and in particular may lead to a title that is longer than suitable for a mobile device.
Refer to 2.4.2 Page Titled, coverage at level A
Tip: While for the mobile context it is important to keep the title short, for the general user it is also important to provide an adequate description. One way to do this (known as “front loading”) is to place the most differentiating information first. More generic information (for example the section of a site) can be placed following this, or omitted for mobile delivery.
Does it help meet any WCAG 2.0 success criteria? Partially.
WCAG 2.0 considers a number of different changes of context. A popup window is one particular change of context. There are three SCs that deal with change of context, caused in three different ways (on focus, on input, and on request): 3.2.1 On Focus, 3.2.2 On Input and 3.2.5 Change on Request. The BP covers only one of the changes of context considered in these three SCs. Refer to 3.2.1 On Focus, coverage at level A, 3.2.2 On Input, coverage at level A and 3.2.5 Change on Request, coverage at level AAA
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? Partially.
It ensures that redirection is initiated only by user request, and therefore partial compliance (in the automatic redirects situation) with success criterion 3.2.5, “Change on Request”.
Refer to 3.2.5 Change on Request, coverage at level AAA
Does it help meet any WCAG 2.0 success criteria? Partially.
It ensures compliance with one aspect (of several) of 1.4.8 Visual Presentation concerning scrolling.
Refer to 1.4.8 Visual Presentation, coverage at level AAA.
Does it help meet any WCAG 2.0 success criteria? Yes, this BP ensures compliance with success criterion 2.4.10 Section Headings with no further effort. It helps towards compliance with success criterion 1.3.1 Info and Relationships.
Refer to 1.3.1 Info and Relationships, coverage at level A and 2.4.10 Section Headings, coverage at level AAA.
Tip: Although the BP has a generic title covering all structural elements, it only mentions section headings. Using other commonly-accepted structural elements not mentioned in the BP can improve usability for mobile users as well as accessibility, and give go some way toward compliance with WCAG success criterion 1.3.1 Info and Relationships. These elements include lists, quotations and citations, table markup, and semantic aspects like emphasis.
Does it help meet any WCAG 2.0 success criteria? Partially.
In order to create content that can be read without style sheets it will probably be necessary to use structural markup, and so this helps compliance with 1.3.1, Info and Relationships.
Refer to 1.3.1 Info and Relationships, coverage at level A.
Does it help meet any WCAG 2.0 success criteria? Possibly.
If content is styled with style sheets it will probably use structural markup, and so this may indirectly bring the same accessibility benefits as STYLE_SHEETS_SUPPORT.
Refer to 1.3.1 Info and Relationships, coverage at level A.
Does it help meet any WCAG 2.0 success criteria? Yes, this ensures compliance with 2.4.3 Focus Order.
Refer to 2.4.3 Focus Order, coverage at level A.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? No, but where tables are not used for layout, this may help towards compliance with 1.3.2 Meaningful Sequence.
Refer to 1.3.2 Meaningful Sequence, coverage at level A
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? No.
Tip: You can improve accessibility when performing testing by involving users with a range of abilities (not only evaluation and development staff). Refer to the WAI resource “Involving Users in Web Accessibility Evaluation” for more information.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? No.
Does it help meet any WCAG 2.0 success criteria? Yes, this BP ensures compliance with success criterion 1.4.1 Use of Color with no further effort. However, it is important to taken into account that unlike the MWBP, the accessibility guidelines specify the ways that color may be used.
Refer to 1.4.1 Use of Color, coverage at level A.
Does it help meet any WCAG 2.0 success criteria? Yes, it ensures compliance with 4.1.1 Parsing with no further effort.
Refer to 4.1.1 Parsing, coverage at level A.