During last week's New York Web Standards meetup on the WCAG Samurai errata, the group generated a few questions that no one could answer. Joe Clark, who led the WCAG Samurai, was kind enough to help out.
All of the WCAG Samurai errata we had questions about are listed below, in
<blockquote>. They are organized by WCAG guidelines in bold.
You can download the PowerPoint presentation and listen to the event at this post: NY Web Standards Meetup—WCAG Samurai Errata for Web Content Accessibility Guidelines (WCAG) 1.0, published on 25 April 2008.
Ensure that pages featuring new technologies transform gracefully
A page that uses digital-rights management or copy protection of any kind cannot be claimed to comply with WCAG+Samurai, as its compatibility with adaptive technology and future technologies cannot be independently proven.
While this seems straightforward, none of us could think of an example. Joe Clark suggested an eBook.
Use interim solutions
Do not cause pop-ups or other windows to appear and do not change the current window without informing the user.
Do not add non-link, printable characters (surrounded by spaces or not) between adjacent links unless the semantics of the document naturally would include such characters.
Navigation schemes marked up like this are a no-no:
<li><a href=""></a> Link 1 |</li>
<li><a href=""></a> Link 2 |</li>
<li><a href=""></a> Link 3</li>
Use the CSS pseudo-element
:after, background images, or borders.
Provide context and orientation information
Do not use frames. (You may use iframes.)
I was curious why
iframes were allowed and wondered how assistive technologies handle them. Joe let me know that assistive technologies handle them "quite well. … Everything inside the
</iframe> is the alternative content, plus it's inline or block so you can do whatever you want with it."
Do not place distinguishing information at the beginning of headings, paragraphs, lists, etc. unless it is significantly harder to understand the document without it. (We do not define "significantly harder.")
We weren't sure what the WCAG meant by "distinguishing information." According to Joe, the WCAG wanted us to front-load everything (headings, paragraphs), so people wouldn't have to read more than a few words to understand what the meaning.
Hidden structural information (e.g., heading elements positioned offscreen) is permitted when document semantics warrant it.
None of us were familiar with this technique or could think of a reason to hide structural information. Joe suggested Googling "offscreen positioning" accessibility:
- "In cases where we need to hide content from a visitor but still make it available to the screenreader, we position it offscreen."
- Accessibility Tips. "Positioning content offscreen."
- "The advantage of offscreen display for iTV captions it that the captions can be much larger and easier to read. The minor disadvantage is that they will be unfamiliar to most viewers for the first few minutes."
- Joe Clark. "Captioning and iTV."
Jeffrey Barke is senior developer and information architect at theMechanism, a multimedia firm in New York City and London.
Published by: jeffreybarke in The Programming Mechanism