This draft is the fourth in a series of reorganization proposals.
W3C published the Web Content Accessibility Guidelines 1.0 (WCAG 1.0) as a Recommendation in May 1999. This Working Draft for version 2.0 builds on WCAG 1.0. It has the same aim: to explain how to make Web content accessible to people with disabilities and to define target levels of accessibility. Incorporating feedback on WCAG 1.0, this Working Draft of version 2.0 focuses on checkpoints. It attempts to apply checkpoints to a wider range of technologies and to use wording that may be understood by a more varied audience.
This document is an editors' copy that has no official standing.
This document is prepared by the Web Content Accessibility Guidelines Working Group (WCAG WG) to show how more generalized (less HTML-specific) WCAG checkpoints might read. This draft is not yet based on consensus of the WCAG Working Group nor has it gone through W3C process. This Working Draft in no way supersedes WCAG 1.0.
This is a draft document and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use W3C Working Drafts as reference material or to cite them as other than "work in progress". A list of current W3C Recommendations and other technical documents is available.
The Working Group welcomes comments on this document at email@example.com. The archives for this list are publicly available. Archives of the WCAG WG mailing list discussions are also publicly available.
Patent disclosures relevant to this specification may be found on the WCAG Working Group's patent disclosure page in conformance with W3C policy.
This document has been produced as part of the W3C Web Accessibility Initiative (WAI). The goals of the WCAG WG are discussed in the Working Group charter. The WCAG WG is part of the WAI Technical Activity.
The text equivalent fulfills the same function as the author intended for the non-text content (i.e. it presents all of the intended information and/or achieves the same function of the non-text content).
non-text content that can not be expressed in words has a text equivalent for all aspects that can be expressed in words.
Editorial Note (06/10/03): There is discussion about moving some of the current success criteria from Required to Best Practice or to an Extended checkpoint. The issue stems from trying to apply the success criteria to every Web cam, newscast, and home broadcast. Another approach is to allow a conformance claim to state, for example, "All pages and applications on this site meet the Core checkpoints of WCAG 2.0 except the Web cam at http://example.org/webcam/."
an audio description is provided.
all significant dialogue and sounds are captioned
If the Web content is real-time and audio-only and not time-sensitive and not interactive a transcript or other non-audio equivalent is sufficient.
Editorial Note: This exception also applies to item 3.
descriptions and captions are synchronized with the events they represent.
if the Web content is real-time video with audio, real-time captions are provided unless the content:
is a music program that is primarily non-vocal
if the Web content is real-time non-interactive video (e.g., a Webcam of ambient conditions), either provide an equivalent that conforms to checkpoint 1.1 (e.g., an ongoing update of weather conditions) or link to an equivalent that conforms to checkpoint 1.1 (e.g., a link to a weather Web site).
if a pure audio or pure video presentation requires a user to respond interactively at specific times in the presentation, then a time-synchronized equivalent (audio, visual or text) presentation is provided.
Editorial Note: This whole Checkpoint (1.2) needs reworking. Perhaps move some down from above, or limit the items above to just certain classes of content - and then put the rest of the coverage (for other types of content) here.
captions and audio descriptions are provided for all live broadcasts.
the presentation does not require the user to read captions and the visual presentation simultaneously in order to understand the content.
the following can be derived programmatically (i.e. through a markup or data model that is assistive technology compatible) from the content without requiring user interpretation of presentation.
any hierarchical elements and relationships, such as headings, paragraphs and lists
any non-hierarchical relationships between elements such as cross-references and linkages, associations between labels and controls, associations between cells and their headers, etc.
any information presented through color is also available without color (e.g. through context or markup or non-color dependent coding). [I#317]
text content is not presented over a background image or pattern OR the text is easily readable when the page is viewed in black and white (no grayscale).
text in the content is provided in Unicode or sufficient information is provided so that it can be automatically mapped back to Unicode.
abbreviations and acronyms are clearly identified each time they occur if they collide with a word in the standard language that would also logically appear in the same case (e.g. all caps). (See also checkpoint 3.1) [I#341]
symbols such as diacritic marks that are found in standard usage of the natural language of the content, and that are necessary for unambiguous identification of words, are present or another standard mechanism for disambiguation is provided.
the structural elements present have a different visual appearance or auditory characteristic from each other and from body text.
the structural emphases are chosen to be distinct on different major visual display types (e.g. black and white, small display, mono audio playback).
Content is constructed such that users can control the presentation of structural elements or the emphasis on the structure can be varied through alternate presentation formats.
text that is presented over a background color or grayscale has a mechanism that allows the text to be presented in a fashion that has a contrast greater than ______ between text and background color as measured by ______.[I#344]
when text content is presented over a background image or pattern, the text is easily readable when the page is viewed in 256 grayscale.
Editorial Note: this item may be moved or updated if the proposal for adding an extended checkpoint on color is accepted.
this item should read identically to the required item #2, except that it should say "in default presentation mode."
Editorial Note: The working group is seeking an algorithm that measures contrast in a way that is accurate and testable enough that we could include it in the guidelines. One algorithm, which comes from the Techniques For Accessibility Evaluation And Repair Tools document, is currently under consideration for inclusion in the techniques, but the group has not yet found something that is specific enough to be included at the guidelines level.
(something to achieve an effect where information can be perceived with common color deficiencies)
content is designed so that time limits are not an essential part of interaction or at least one of the following is true for each time limit:
the user is allowed to deactivate the time limits,
or the user is allowed to adjust the time limit over a wide range which is at least ten times or default setting or average user's preference,
or the user is warned before time expires and given at least 10 seconds to extend the time limit,
or the time limit is due to a real-time event (e.g. auction) and no alternative to the time limit is possible,
or the time limit is part of a competitive activity where timing is an essential part of the activity (e.g. competitive gaming or time based testing).
any moving content can be frozen using the keyboard[I#325]
Editorial Note (06/10/03): This Checkpoint is currently included in the Core set of Checkpoints because the WCAG WG expects that it will be possible to test content for flicker and the result will be a flicker rate in Hz that can be stored in a machine-readable format. If the assumption regarding a testing tool does not hold at time of final review of these guidelines, this checkpoint will be moved to the Extended set of Checkpoints."
At least one of the following is true:
content was not designed to flicker (or flash) in the range of 3 to 49 Hz.
if flicker is unavoidable, the user is warned of the flicker before they go to the page, and as close a version of the content as is possible without flicker is provided.
Editorial Note: We would like to include a third criteria here that would state that a test that was conducted and the pages passed. No test or tool exists yet though. We're looking into how such a test and/or tool might be designed.
animation or other content does not visibly or purposely flicker between 3 and 49 Hz.
content that might create a problem has been tested [using XYZ tool]; only pages with unavoidable flicker remain and appropriate warnings along with a close alternative presentation have been provided for these pages.
Editorial Note: The CKW reorganization proposed that all of the items in required be removed and proposed a rewording of the item in best practice that addressed logical, linear reading order. [I#441]
In documents greater than 50,000 words or sites larger than 50 perceived pages, at least one of the following is provided.
Users are able to skip over large blocks of repetitive material, navigational bars or other blocks of links that are greater than 7 when reading with a synthesizer or navigating using keyboard.[I#323]
the content has been reviewed, taking into account the following strategies for facilitating orientation and movement, applying them as appropriate.
breaking up text into logical paragraphs
providing hierarchical sections and titles, particularly for longer documents
revealing important non-hierarchical relationships, such as cross-references, or the correspondence between header and data cells in a table, so that they are represented unambiguously in the markup or data model
dividing very large works into sections and or chapters with logical labels
information is provided that would allow an assistive technology to determine at least one logical, linear reading order.
diagrams are constructed in a fashion so that they have structure that can be accessed by the user.
where possible, logical tab order has been created.[I#319]
Editorial Note: The CKW proposal suggested that this required success criterion be combined with one of the best practice items and that another best practice item be moved up. [I#440]
if an error is detected, feedback is provided to the user identifying the error (in an accessible form that meets core checkpoints).
where possible, the user is allowed to select from a list of options as well as to generate input text directly
errors are identified specifically and suggestions for correction are provided where possible
checks for misspelled words are applied and correct spellings are suggested when text entry is required.
where consequences are significant and time-response is not important, one of the following is true
actions are reversible
where not reversible, actions are checked for errors in advance
where not reversible, and not checkable, a confirmation is asked before acceptance
passages or fragments of text occurring within the content that are written in a language other than the primary natural language of the content as a whole, are identified, including specification of the language of the passage or fragment.
Foreign words or phrases that are found in standard unabridged dictionaries for the natural language of the content do not need to be marked.
This success criterion applies only to foreign words, not to imaginary words, dialect abbreviations and other words that may not be found in an unabridged dictionary of the primary language but that are not foreign words.
[???] document attributes identify the natural language of the document.
Editorial Note: In techniques discussion, it has been argued that language attributes for documents are as important as identifying changes in language within documents. Moving it up here for future discussion.
acronyms and abbreviations do not appear first in standard unabridged dictionaries for the language or define the first time the first time they appear or are available in a glossary on the site.[I#330]
Editorial Note: If a standard format for doing it can be achieved, we might require that linkages to glossaries for all abbreviations and acronyms that are created by the author or site be provided. We could also recommend that linkages to any abbreviations, acronyms, etc. used by the authors also be provided. We could also have a weaker recommendation for acronyms and abbreviations appearing on the site that linkages to glossaries explaining all abbreviations acronyms, etc. that appear in any documents on the site be provided.
a list is provided on the page or home page of URIs to cascading dictionaries that can or should be used to define abbreviations or acronyms.[I#350]
the content has been reviewed, taking into account the following strategies for determining the definition of abbreviations and acronyms, applying them as appropriate.
provide a definition or link (with the first occurrence) of phrases, words, acronyms, and abbreviations specific to a particular community.
provide a summary for relationships that may not be obvious from analyzing the structure of a table but that may be apparent in a visual rendering of the table.
if contracted forms of words are used such that they are ambiguous, provide semantic markup to make words unique and interpretable.
the content has been reviewed, taking into account the following strategies for evaluating the complexity of the content, applying them as appropriate.
familiarity of terms and language structure
reasonableness of length and complexity of sentences
coherence of paragraphs (and sensibility in length)
clarity of headings and linked text when read out of context
accuracy and uniqueness of page titles
care in the use of all-capital letters where normal sentence case might increase comprehension
inclusion of non-text content to supplement text for key pages or sections of the site where they felt it was appropriate.
key orientation and navigational elements (such as navigation bars) are generally found in one or two consistent locations or their locations are otherwise predictable.
where inconsistent or unpredictable responses are essential to the function of the content (e.g. mystery games, adventure games, tests, etc.) the user is warned in advance of encountering them.
wherever there are extreme changes in context, one of the following is true:
an easy to find setting, that persists for the site visit, is provided for the user to deactivate processes or features that cause extreme changes in context or
extreme changes in context are identified before they occur so the user can determine if they wish to proceed or so they can be prepared for the change
user can select a different location for navigation elements in the layout of the page.[I#352]
the content has been reviewed, taking into account common ideas for making content consistent and predictable, applying them as appropriate.
for markup, except where the site has documented that a specification was violated for backward compatibility, the markup has:
passed validity tests of the language (whether it be conforming to a schema, Document Type Definition (DTD), or other tests described in the specification)
structural elements and attributes are used as defined in the specification
accessibility features are used
deprecated features are avoided
Editorial Note: The following two success criteria seem to overlap with checkpoint 4.3. There is an open question about whether they should be deleted since checkpoint 4.3 covers programmatic interfaces.
any custom user interface elements of the content conform to at least Level A of the User Agent Accessibility Guidelines 1.0. If the custom user interfaces cannot be made accessible, an alternative solution is provided that meets WCAG 2.0 (including this provision) to the level claimed.
Editorial Note: This checkpoint includes a slightly reworded version of the suggestions from CKW reorganization. However, the following elements appeared to be redundant with the first sentence. Can they be removed?
If the application renders visual text, it should conform to the VisualText checkpoints.
If the application renders images, it should conform to the Image checkpoints.
If the application renders animations, it should conform to the Animation checkpoints.
If the application renders video, it should conform to the Video checkpoints.
If the application renders audio, it should conform to the Audio checkpoints.
If the application performs its own event handling, it should conform to the Events checkpoints.
If the application implements a selection mechanism, it should conform to the Selection checkpoints.
If the application implements voice or pointer input, it should conform to the Input Modality checkpoints.
accessibility conventions of the markup or programming language (API's or specific markup) are used (@@in UAAG somewhere?)
plug-ins required to access the content conform to at least Level A of UAAG 1.0. If required plug-ins are not accessible, an alternative solution is provided that conforms to WCAG 2.0.
accessibility conventions of the markup or programming language (API's or specific markup) are used [I#331]
the interface has been tested using a variety of assistive technologies and preferably real people with disabilities who use assistive technologies to determine that those assistive technologies are able to access all information on the page or hidden within the page.
the Web resource includes a list of the technologies (other than standard HTML) users must have in order for its content to work as intended. Users who do not have one or more of these technologies can still access and use the resource, though the experience may be degraded.
When determining your list of technological requirements, consider that assistive hardware and software is often slow to adapt to technological advances, and the availability of assistive technology varies across natural languages. Verify that assistive technology compatible with the technologies you choose is available in the natural language(s) of your content.
Editorial Note: This checkpoint is currently in the set of extended checkpoints. The implications of this are that there is no core checkpoint that says content must transform gracefully or that it must be backwards compatible. However, if the set of core checkpoints is designed well, core conformance would result in content that transforms gracefully. This checkpoint might be too subjective or difficult to test and may be deleted.
a list of technologies and features, support for which is required in order for the content to be operable, has been determined and is documented in metadata and / or a policy statement associated with the content.
technologies and features on the required list are available in at least two independently-developed implementations. (it is preferable that the technologies used for the implementations have been supported for at least one prior version of the software)