From WCAG 2.0 to MWBP 1.0: Making content that meets Web Content Accessibility Guidelines 2.0 also meet Mobile Web Best Practices 1.0

W3C Editor's Draft 01 September 2008

Table of Contents


Incomplete draft: This document is an in-progress Working Draft provided for review and feedback. It is incomplete and will likely have major changes. See also Status of this Document in the overview page.
Please send feedback to public-bpwg-comments@w3.org (with public archive).

This page is part of a multi-page document. Please refer to the “How to Use This Document” section for more information.

This page describes how some WCAG success criteria (SC) can help with achieving compliance with the Mobile Web Best Practices 1.0 (MWBP). For content that already complies with WCAG, it outlines what may need to be done to comply with each BP.

As described in this section, many SCs have the added benefit of partial or complete compliance with certain BPs. However, the best practices may describe a different aspect of the same concept. It should not be assumed that following any SC will ensure compliance with the MWBP. To ensure compliance it is important to always consult the Mobile Web Best Practices 1.0 [MWBP1.0] or the Web Content Accessibility Guidelines 2.0 [WCAG2.0].

Summary of work required to make content that meets WCAG 2.0 also meet MWBP

Compliance with WCAG 2.0 helps go some way towards achieving compliance with some of the MWBP. This section provides a summary of these BPs. There are two possible levels of effort required, labelled for simplicity with the keywords nothing and something. Refer to definition of use of these terms in Appendix B: Special Terms. Note that coverage may depend on WCAG compliance level achieved and so a BP may appear in “something” and “nothing” lists (for example, LINK_TARGET_ID). To summarise, if your content already complies with WCAG 2.0, to achieve compliance with the MWBP, you need to do the following:

Nothing: Content that already meets WCAG 2.0 should already meet these BPs. SC and BP links in this section point to the relevant Recommendation. Refer to the description of each success criterion for an explanation of how and in what way it meets the BP.

Something: More effort of some kind or a check, is necessary to ensure compliance with these BPs. Refer to the description of each success criterion for an explanation of how and in what way it partially or possibly meets the BP. BP links in this section point to detail sections below; SC links to the MWBP Recommendation.

Addressing Mobile Web Best Practices

This section deals with each of the best practices which WCAG 2.0 helps with meeting. For each BP, the section title is that of the BP. This is followed by a list of the SCs that can help meet it.

[BACKGROUND_IMAGE_READABILITY] When using background images make sure that content remains readable on the device

If overall contrast is sufficient, this goes part of the way to ensuring readability with background images.

[COLOR_CONTRAST] Ensure that foreground and background color combinations provide sufficient contrast

Unlike MWBP, WCAG specifies a contrast ratio and algorithm and certain types of content that are excluded from the requirement. The following SCs may ensure compliance with this BP, if content covered by the BP is not excluded.

[CONTROL_LABELLING] Label all form controls appropriately and explicitly associate labels with form controls

The following SCs ensure compliance with this BP when the label element is used for form controls.

[CONTROL_POSITION] Position labels so they lay out properly in relation to the form controls they refer to

[GRAPHICS_FOR_SPACING] Do not use graphics for spacing

[MEASURES] Do not use pixel measures and do not use absolute units in markup language attribute values and style sheet property values

WCAG 2.0 does not prohibit the use of the pixel unit of measure.

[NON-TEXT_ALTERNATIVES] Provide a text equivalent for every non-text element

Note that the WAI Glossary definition of Non-text Content which is the basis for this BP, includes video and audio.

[OBJECTS_OR_SCRIPT] Do not rely on embedded objects or script

[PAGE_TITLE] Provide a short but descriptive page title

[POP_UPS] Do not cause pop-ups or other windows to appear and do not change the current window without informing the user

[REDIRECTION] Do not use markup to redirect pages automatically. Instead, configure the server to perform redirects by means of HTTP 3xx codes

The following SCs go some way to achieving compliance with this BP. Specifically, failure F41: Failure of Success Criterion 2.2.1, 2.2.4, and 3.2.5 due to using meta refresh with a time-out ensures compliance with this BP.

[STRUCTURE] Use features of the markup language to indicate logical document structure

The BP is less explicit about what structural elements to use, but the following SCs probably cover its intent.

[VALID_MARKUP] Create documents that validate to published formal grammars