- From: Ian Jacobs <ij@w3.org>
- Date: Wed, 19 Jul 2000 16:30:01 -0400
- To: w3c-wai-ua@w3.org
Hello,
In the 7 July UA Guidelines, checkpoint 2.7 reads:
2.7 For author-identified but unsupported natural
languages, allow the user to configure the user
agent to identify those language changes in content.
At the 13 July teleconference [2], I expressed a concern about
proposing the minimal requirement be to render the information
"in content" and got an action item to propose a change.
Please consider the following proposals:
1) Delete checkpoint 2.7. This checkpoint was initially
included in the UA Guidelines in support of the WCAG 1.0
checkpoint 4.1:
Clearly identify changes in the natural language of a
document's text and any text equivalents (e.g., captions).
As I recall, this checkpoint was included as a P1 requirement
to that screen readers capable of handling several languages might
switch dictionaries. However, checkpoint 2.7 is not about making
the markup provided by the author available to assistive
technologies;
it's abount rendering through the native UI. In my opinion,
our requirements to implement the DOM are the appropriate
reflection of the WCAG 1.0 requirement. And therefore, if the
checkpoint is not about the UI, I think we should delete it.
2) Don't delete checkpoint 2.7 because rendering content written in
an unsupported natural language with incomprehensible glyphs or
sounds may cause accessibility problems. I don't think we should
argue
that the problems are for assistive technologies (since they should
get
the information through the DOM). But we could argue for that many
users, including users with some disabilities, viewing content
through
a native viewport when that content is rendered as garbage may be
disorienting. We should either require the UA not to render garbage,
or to identify it as such.
I would note that the HTML specification, section 5.4 [5] discusses
the handling of undisplayable characters. It recommends the following
to user agents:
Adopt a clearly visible, but unobtrusive mechanism to
alert the user of missing resources.
Please consider the following wording for a revised P3 checkpoint:
<NEW>
2.7 For content in a recognized but unsupported natural
language, allow configuration so that when rendered,
this content does not disorient the user. The user
agent may choose to not render this content, but must
indicate the absence through the user interface.
Note: For example, if the user agent does not support
Japanese, render "[Japanese text]" instead of the content,
or use an accessible icon that indicates an unsupported language.
</NEW>
Other techniques:
- Render the name of the language and use a colored background
to indicate that content is garbage.
Notes:
- I have removed the part about the text being marked-up
by the author. I think the requirement should apply for
any text content recognized by the user agent as being
in an unsupported natural language. The techniques document
talks about ways to identify natural language.
- The requirement used to only be about changes in natural language.
However, I think the accessibility issue raised above applies
for all unsupported natural languages, even if the entire document
is in that language.
IMPORTANT: We decided (refer ot issue 174) to remove a requirement
to render content according to natural language specifications
because
we said that not doing so was not an accessibility issue. I'm arguing
here that rendering junk without warning the user that it's junk
may be an accessibility issue.
- Ian
[1] http://www.w3.org/WAI/UA/WD-UAAG10-20000707/
[2] http://lists.w3.org/Archives/Public/w3c-wai-ua/2000JulSep/0056.html
[3] http://lists.w3.org/Archives/Public/w3c-wai-ua/2000AprJun/0448.html
[4] http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505
[5] http://www.w3.org/TR/1999/REC-html401-19991224/charset.html#h-5.4
[6] http://cmos-eng.rehab.uiuc.edu/ua-issues/issues-linear.html#174
--
Ian Jacobs (jacobs@w3.org) http://www.w3.org/People/Jacobs
Tel: +1 831 457-2842
Cell: +1 917 450-8783
Received on Wednesday, 19 July 2000 16:30:02 UTC