Cabinet Office
The Web Content Accessibility Guidelines (WCAG) are dated 5 May 1999 as Version 1. There are three Levels of conformance with this guideline:
Each checkpoint has a priority level assigned by the Working Group based on the checkpoint's impact on accessibility.
A web content developer must satisfy this checkpoint. Otherwise, one or more groups will find it impossible to access information in the document. Satisfying this checkpoint is a basic requirement for some groups to be able to use web documents.
A web content developer should satisfy this checkpoint. Otherwise, one or more groups will find it difficult to access information in the document. Satisfying this checkpoint will remove significant barriers to accessing web documents.
A web content developer may address this checkpoint. Otherwise, one or more groups will find it somewhat difficult to access information in the document. Satisfying this checkpoint will improve access to web documents
The rest of this appendix summarises the guidelines (covering Priorities 1 to 3) and the checkpoints (covering Priority 1 only). This material is an extract from a much longer document of the key points about the guidelines and the levels of conformance (for further information see www.w3.org/TR/WCAG10/) [External website].
| Checkpoints for Priority | ||||
|---|---|---|---|---|
| Guideline | 1 | 2 | 3 | |
| 1 | Provide equivalent alternatives to auditory and visual content Provide content that, when presented to the user, conveys essentially the same function or purpose as auditory or visual content. |
4 | 0 | 1 |
| 2 | Don't rely on colour alone Ensure that text and graphics are understandable when viewed without colour |
1 | 1 | (1) |
| 3 | Use markup and style sheets and do so properly Mark up documents with the proper structural elements. Control presentation with style sheets rather than with presentation elements and attributes. |
0 | 7 | 0 |
| 4 | Clarify natural language usage Use markup that facilitates pronunciation or interpretation of abbreviated or foreign text. |
1 | 0 | 2 |
| 5 | Create tables that transform gracefully Ensure that tables have necessary markup to be transformed by accessible browsers and other user agents. |
2 | 2 | 2 |
| 6 | Ensure that pages featuring new technologies transform gracefully Ensure that pages are accessible even when newer technologies are not supported or are turned off. |
3 | 2 | 0 |
| 7 | Ensure user control of time-sensitive content changes Ensure that moving, blinking, scrolling, or auto-updating objects or pages may be paused or stopped. |
3 | 4 | 0 |
| 8 | Ensure direct accessibility of embedded user interfaces Ensure that the user interface follows principles of accessible design: device-independent access to functionality, keyboard operability, self-voicing, etc. |
1 | 0 | 0 |
| 9 | Design for device-independence Use features that enable activation of page elements via a variety of input devices. |
1 | 2 | 2 |
| 10 | Use interim solutions Use interim accessibility solutions so that assistive technologies and older browsers will operate correctly. |
0 | 2 | 3 |
| 11 | Use W3C technologies and guidelines Use W3C technologies (according to specification) and follow accessibility guidelines. Where it is not possible to use a W3C technology, or doing so results in material that does not transform gracefully, provide an alternative version of the content that is accessible. |
0 | 2 | 1 |
| 12 | Provide context and orientation information Provide context and orientation information to help users understand complex pages or elements. |
1 | 3 | 0 |
| 13 | Provide clear navigation mechanisms Provide clear and consistent navigation mechanisms – orientation information, navigation bars, a site map, etc. –to increase the likelihood that a person will find what they are looking for at a site. |
0 | 4 | 6 |
| 14 | Ensure that documents are clear and simple Ensure that documents are clear and simple so they may be more easily understood. |
1 | 0 | 2 |
| Total | 18 | 29 | 19 | |
A selection of pages has completely passed an extensive selection of Priority 1 checks, including a range of checks that can only be assessed through manual inspection.
A limited selection of pages has completely passed a limited selection of Priority 1 checks, but involves only fully automated checks on a subset of pages. Site may therefore fully conform at Level A.
Limited failure occurs in Level A conformance, below specific quantitative thresholds. Site fails a limited number of distinct Priority 1 checks and/or on a limited number of pages and/or a limited number of failure instances, but involves only fully automated checks on a subset of pages. Checkpoints that require manual checking have not been verified.
Extensive failure occurs in Level A conformance. Site fails multiple distinct Priority 1 checks and/or multiple pages and/or multiple failure instances, but involves only fully automated checks on a subset of pages. Checkpoints that require manual checking have not been verified.
In particular the notion of ‘Marginal Fail Level A’ used in this study relates solely to the results from the automated assessments. To avoid being overly harsh in rating sites on the basis of the automated checks, we included ‘marginal’ allowances for some criteria. For example, to fail a site that has thousands of images, on the basis of finding just one image that lacks an ‘alt’ attribute, would appear to be rather extreme. It is simplistic, and potentially misleading, to equate such a site with one where no images at all have been made accessible. Hence, a small marginal allowance of failed images is allowed. Similar small allowances were made for some of the other automated assessment criteria.
If any of the following automated assessments results in a ‘marginal’ rating, the overall classification for that site is designated as Marginal Fail Level A.
Images without an ALT attribute:
Image map hotspots (AREA) without an ALT attribute:
APPLET elements without an ALT attribute:
FRAMESETS with no NOFRAMES content:
FRAMES with no TITLE attribute: