Web and Software: Web provisions
Contents |
22(a)
Current wording: A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content).
- Recommendation: Adopt WCAG 2.0 success criterion 1.1.1. Addresses concerns of captchas, null alt text for decorative images and provisions for multimedia.
22(b)
Current wording: Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation.
- Discussed at the November 15, 2006 meeting. Defer this to the Audio Video Subcommittee.
22(c)
Current wording: Web pages shall be designed so that all information conveyed with color is also available without color, for example from context or markup.
- WCAG 2.0 wording is still evolving so it's probably too early to harmonize.
- Conclusion: The subcommittee recommends no change at this time to 22(c).
22(d)
Current wording: Documents shall be organized so they are readable without requiring an associated style sheet.
- This requirement is no longer needed. What is important is that the content have structure and that the reading order can be determined.
- New technologies for rich Internet applications (RIA) cannot work with CSS disabled. If this remains in 508, RIAs will not be able to conform to 508 even though they can be made to be accessible.
- Recommendation: Remove this requirment and add one on structure and reading order.
- When the sequence in which content is presented affects its meaning, a correct reading sequence is programmatically determinable.
- programmatically determinable is defined as: can be determined by software from data provided in a user-agent-supported manner such that various user agents including assistive tecnologies can extract and present this information to users in different modalities.
- Note: This definition and its connection to assitive technologies needs further discussion.
22(e) and 22(f)
Current wording:
- (e) Redundant text links shall be provided for each active region of a server-side image map.
- (f) Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape.
- HTML specific.
- (f) essentially makes any server side image maps not compliant with Section 508.
- The issue is keyboard accessibility. "Redundant text links" is too prescriptive. There are other ways to provide keyboard equivalents.
- Recommendation: Remove (e) and (f) and add the proper provisions from WCAG 2.0 to ensure image maps are accessible. Keyboard accessibility (WCAG 2.1.1) and meaningful link names (WCAG 2.4.4) may cover them sufficiently.
- 2.1.1 All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying task requires analog, time-dependent input.
- Note: Alternative proposals are currently under discussion in the subcommittee.
- 2.4.4 The purpose of each link can be determined from the link text and its programmatically determined link context.
- 2.1.1 All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying task requires analog, time-dependent input.
22(g) and 22(h)
Current wording:
- 22(g) Row and column headers shall be identified for data tables.
- 22(h) Markup shall be used to associate data cells and header cells for data tables that have two or more logical levels of row or column headers.
- Harmonization with WCAG 2.0 is a good idea but concern that moving the table requirements to "sufficient techniques" will soften the requirement. Suggest including in the standard as examples.
- Proposal (subject to subcommittee approval): Replace (g) and (h) with:
- Information and relationships conveyed through presentation can be programmatically determined, and notification of changes to these is available to user agents, including assistive technologies. For example:
- row and column headers are identifed for data tables
- markup is used to associate data cells and header cells for data tables that have two or more logical levels of row or column headers.
- Information and relationships conveyed through presentation can be programmatically determined, and notification of changes to these is available to user agents, including assistive technologies. For example:
22(i)
Current wording: Frames shall be titled with text that facilitates frame identification and navigation.
- Frames are HTML specific. There are a lot of techniques required to make frames accessible. WCAG 2.0 addresses frames in techniques for several success criteria.
- No consensus to harmonize with WCAG 2.0 on this.
22(j)
Current wording: Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 55 Hz.
- WCAG 2.0 introduced the idea of a minimum size. This is good because only flashing areas that are larger than a defined size are an issue. For example, a blinking text caret is not large enough to trigger a seizure even if it is flashing within the 2 to 55 Hz range.
- Proposal currently under discussion: When software has flashing or blinking elements that occupy more than one quarter of any 341 x 256 pixel rectangle anywhere on the displayed screen area when viewed at 1024 x 768 pixels, the flashing or blinking elements shall not have a flash or blink frequency greater than 2 Hz and lower than 55 Hz.
- Further discussion of harmonizing this with WCAG 2.0 is on hold until WCAG 2.0 wording is more mature.
22(k)
Current wording: A text-only page, with equivalent information or functionality, shall be provided to make a web site comply with the provisions of this part, when compliance cannot be accomplished in any other way. The content of the text-only page shall be updated whenever the primary page changes.
- Not necessary because of equivalent facilitation.
- Recommendation: Remove this requirement.
22(l) & 22(m)
Current wording: When pages utilize scripting languages to display content, or to create interface elements, the information provided by the script shall be identified with functional text that can be read by assistive technology.
Current wording: When a web page requires that an applet, plug-in or other application be present on the client system to interpret page content, the page must provide a link to a plug-in or applet that complies with §1194.21(a) through (l).
- For those who have to comply with WCAG 2.0 and Section 508, having a requirement in 1194.22 that refers back to 1194.21, means that developers will have to answer questions twice - once for WCAG 2.0 and again for 508.
- Two particular problems in this area that need to be addressed with sufficient techniques are:
- Keyboard focus - traversal into and out of applets and plug-ins
- Color/contrast - inheriting the system settings within the applet or plug-in.
- Generally in favor of WCAG 2.0 approach - have provisions in the Section 508 Web section that would address interactive content (applets, plug-ins, scripts) without referring to the software requirements. Need to investigate if all of the current 508 software provisions are addressed by WCAG 2.0. See the mapping of current software provisions to WCAG 2.0.
22(n)
Current wording: When electronic forms are designed to be completed on-line, the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues.
- Some favor the WCAG 2.0 method which is to have a general testable requirement on interactive elements backed up by more specific techniques for HTML forms, JavaScript, AJAX, etc.
- Some favor a specific provision in Section 508 addressing Web forms.
22(o)
Current wording: A method shall be provided that permits users to skip repetitive navigation links.
- Skip links don't work right in most browsers. They move the viewport but not the keyboard focus.
- In WCAG 2.0, this is addressed in 2.4.1 "A mechanism is available to bypass blocks of content that are repeated on multiple Web units." So WCAG 2.0 is broader than 508. It applies to any kind of repeated content, not just navigation links.
- The real requirement is for efficient keyboard navigation, not just skipping repeated content. If the document has structure as required by WCAG 2.0 success criterion 1.3.1, then keyboard navigation can be provided by the user agent.
- Note: Screen readers will now figure out the repetitive navigation links and skip them automatically without developers doing anything.
- W3C User Agent Accessibility Guidelines require user agents to provide keyboard navigation of structure but currently only screen readers are doing this.
- Recommendation (subject to subcommittee approval): Remove this requirement and add 1.3.1 and 2.4.1 from WCAG 2.0:
- 1.3.1 Information and relationships conveyed through presentation can be programmatically determined, and notification of changes to these is available to user agents, including assistive technologies.
- 2.4.1 A mechanism is available to bypass blocks of content that are repeated on multiple Web pages.
22(p)
Current wording: When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required.
- Testability issue - what is "sufficient time"?
- WCAG 2.0 provides several strategies for addressing timed responses. Section 508 is very prescriptive in only allowing one strategy.
- Recommendation: Harmonize with WCAG 2.0.
- For each time limit that is set by the content, at least one of the following is true:
- Deactivate: the user is allowed to deactivate the time limit; or
- Adjust: the user is allowed to adjust the time limit over a wide range that is at least ten times the length of the default setting; or
- Extend: the user is warned before time expires and given at least 20 seconds to extend the time limit with a simple action (for example, "hit any key"), and the user is allowed to extend the time limit at least ten times; or
- Real-time Exception: the time limit is an important part of a real-time event (for example, an auction), and no alternative to the time limit is possible; or
- Essential Exception: the time limit is part of an activity where timing is essential (for example, competitive gaming or time-based testing) and time limits can not be extended further without invalidating the activity.
- For each time limit that is set by the content, at least one of the following is true:
