Web and Software: Web Like WCAG 2 0

1194.22 Proposal

This proposal describes changes and additions to part 1194.22 of Section 508 to address the following:

1. Web provisions draft containing recommendations already agreed to by the subcommittee
2. New provisions from 1194.21 that will enable the 1194.22 to be a complete set of requirements for any Web content including scripts, applets, and plug-ins. That is, developers will not need to refer back to 1194.21 for any requirements. See the mapping of 1194.21 provisions to WCAG 2.0 provisions.

Definitions Relevant to this section

• programmatically determinable: 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.

Technical Standards

• 1194.22 (a) (Consensus was to harmonize the text alternative provision with WCAG 2.0 which currently reads:)
  • Non-text Content: Except for the situations listed below, a text alternative that presents equivalent information shall be provided for all non-text content.
    • Controls-Input: If non-text content is a control or accepts user input, then it has a name that describes its purpose. (See also 1194.22 (k))
    • Media-Test-Sensory: If non-text content is multimedia , live audio-only or live video-only content, a test or exercise that must be presented in non-text format, or primarily intended to create a specific sensory experience , then text alternatives at least identify the non-text content with a descriptive text label. (For multimedia, see also 1194.22 (b))
    • CAPTCHA*: If the purpose of non-text content is to confirm that content is being accessed by a person rather than a computer, then a descriptive text label describing its purpose is provided and different forms are provided to accommodate different disabilities.
    • Decoration-Formatting-Invisible: If non-text content is pure decoration, or used only for visual formatting, or if it is not presented to users, then it is implemented such that it can be ignored by assistive technology.

• 1194.22 (b) (Synchronized equivalents for multimedia - defer the wording of this requirement to the A/V subcommittee or refer to the A/V section.)

• 1194.22 (c) (No change.)
  • Web pages shall be designed so that all information conveyed with color is also available without color, for example from context or markup.

• 1194.22 (d) (New provision - replaces style sheet provision.)
  • When the sequence in which content is presented affects its meaning, a correct reading sequence shall be programmatically determinable.

• 1194.22 (e) (New provision on keyboard operability currently being worked in sub-team - replaces server side image map provision.)

• 1194.22 (f) (New provision - added to complete what is needed to make server side image maps accessible. Replaces client side image map provision.)
  • The purpose of each link shall be capable of being determined from the link text and its programmatically determinable link context.

• 1194.22 (g) (New provision - replaces provisions on table headers.)
  • Information and relationships conveyed through presentation shall be programmatically determinable, 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.

• 1194.22 (h) (New provision - focus cursors are provided by user agents for HTML content but this provision is needed for other technologies.)
  • A focus cursor shall be provided that visually indicates which user interface element currently has the keyboard input focus, as well as the focus location within that element when one exists. The focus cursor shall be programmatically determinable so that assistive technology can track focus and focus changes.
    • Note: may be affected by the proposal that is pending from the AT-IT interoperability sub-team.

• 1194.22 (i) (No change.)
  • Frames shall be titled with text that facilitates frame identification and navigation.

• 1194.22 (j) (Modified upper bound from 55 Hz to 50 Hz for harmonization with WCAG 2.0 and ISO. It is believed that this is a typo in the current 508 standard.)
  • Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 50 Hz.
    • Note: WCAG 2.0 provision is less restrictive but harder to understand and requires a tool being developed by Trace for assessment.

• 1194.22 (k) (New provision - semantic HTML elements meet this provision but it is needed for other Web technologies. Replaces provision on providing an alternative text only page which is not needed. Providing alternative versions is fundamental to all requirements through equivalent facilitation.)
  • For all user interface components, the name and role shall be programmatically determinable, states, properties, and values that can be set by the user shall be programmatically determinable and can be programmatically set, and notification of changes to these items is available to user agents, including assistive technologies.

• 1194.22 (l) (No change.)
  • 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.
    • Note: This is not needed because everything required to make scripts accessible is covered by the other provisions but we did not reach consensus to remove it.

• 1194.22 (m) (New provision - added to cover 1194.21(e). Replaces provision on applets and plug-ins, not needed in this proposal which covers everything in 1194.21.)
  • Components that have the same functionality within a set of Web units shall be identified consistently.

• 1194.22 (n) (No change.)
  • 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.
    • Note: Forms are addressed in this proposal with 1194.22 (g), (h), and (k) so this can probably be removed. Could also add the following requirements from WCAG 2.0 that support forms:
      • Information required to understand and operate content shall not rely on shape, size, visual location, or orientation of components.
      • If an input error is detected, the error shall be identified and described to the user in text.
      • When any component receives focus, it shall not cause a change of context.
      • Changing the setting of any form control or field shall not automatically cause a change of context (beyond moving to the next field in tab order), unless the authored unit contains instructions before the control that describe the behavior.

• 1194.22 (o) (Reworded provision to harmonize with WCAG 2.0.)
  • A mechanism shall be available to bypass blocks of content that are repeated on multiple Web pages.

• 1194.22 (p) (New provision - added to cover time limits from 1194.21.)
  • For each time limit that is set by the content, at least one of the following is true:
    • Deactivate: the user shall be allowed to deactivate the time limit; or
    • Adjust: the user shall be 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 shall be 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.

• 1194.22 (q) (New provision - added to cover animations from 1194.21 but worded consistently with WCAG 2.0.)
  • Content shall be capable of being paused by the user unless the timing or movement is part of an activity where timing or movement is essential.

• 1194.22 (r) (New provision - added to cover contrast from 1194.21 but worded consistently with WCAG 2.0.)
  • Text, images of text, or diagrams, and their respective backgrounds, shall have a luminosity contrast ratio of at least n:1.

1194.21 Provisions not addressed by the above proposal

• Applications shall not disrupt or disable activated features of other products that are identified as accessibility features, where those features are developed and documented according to industry standards. Applications also shall not disrupt or disable activated features of any operating system that are identified as accessibility features where the application programming interface for those accessibility features has been documented by the manufacturer of the operating system and is available to the product developer.

• Applications shall not override user selected contrast and color selections and other individual display attributes.

References

• Draft of final deliverable on Web provisions which describes where we ended up on our discussion of existing 1194.22 provisions.
• Mapping of 1194.21 to WCAG 2.0 provisions
• Discussions on gaps in Web requirements