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Re: "For dependent user agents"

From: Ian Jacobs <ij@w3.org>
Date: Fri, 27 Aug 1999 18:30:24 -0400
Message-ID: <37C71180.71F72463@w3.org>
To: Jon Gunderson <jongund@staff.uiuc.edu>
CC: Kitch Barnicle <kab42@columbia.edu>, w3c-wai-ua@w3.org
Jon Gunderson wrote:
> 
> Response in JRG:
> 
> At 02:39 PM 8/20/99 -0500, Kitch Barnicle wrote:

> >I have been reading the guidelines with the notion that those check points
> >that say "For Dependent User Agents" in front of them, only apply to
> >dependent user agents.  However in several cases that didn't seem to make
> >sense. For example why would  checkpoints 7.3, "Render content according to
> >natural language identification," or 9.3 "Allow the user to view a document
> >outline constructed from its structural elements." only apply to dependent
> >user agents.?
> 
> JRG: Natural language means that if the user agent can identify the
> langauge of
> the element content (primarily markup of the element) that the user agent
> should render through speech, visual or braille that appropriate language.  It
> seems to me that this should apply to all user agents, I am not sure why it is
> just for dependent user agents.

I think you're right and it should be for all user agents.

BACKGROUND: We have mostly been thinking about how speech
and braille devices can switch dictionaries automatically
when there's a marked up change in language.

However, the checkpoint applies to graphical desktop browsers
that support HTML as well. From the HTML 4.0 spec, section 8.2 [1]:

   > If a document contains right-to-left characters,
   > and if the user agent displays these characters, 
   > the user agent must use the bidirectional algorithm. 

[1] http://www.w3.org/TR/REC-html40/struct/dirlang.html#h-8.2

In other words, user agents are supposed to handle bidi
text correctly (although they may not have a font handy
to display the text). 

Furthermore, HTML user agents are meant to support "lang", 
presumably on screen as well as on other devices. From
HTML 4.0, section 8.1 [2]:

> The intent of the lang attribute is to allow user agents
> to render content more meaningfully based on accepted cultural
> practice for a given language. This does not imply that 
> user agents should render characters that are atypical for a
> particular language in less meaningful ways; user agents
> must make a best attempt to render all characters, regardless
> of the value specified by lang. 
> 
> For instance, if characters from the Greek alphabet 
> appear in the midst of English text: 
> 
>   <P><Q lang="en">Her super-powers were the result of
>   &gamma;-radiation,</Q> he explained.</P>
> 
> a user agent (1) should try to render the English content 
> in an appropriate manner (e.g., in its handling the
> quotation marks) and (2) must make a best attempt to 
> render &gamma; even though it is not an English
> character. 

Presumably, this would involve choosing a suitable glyph
for rendering a gamma.

[2] http://www.w3.org/TR/REC-html40/struct/dirlang.html#h-8.1

 - Ian

-- 
Ian Jacobs (jacobs@w3.org)   http://www.w3.org/People/Jacobs
Tel/Fax:                     +1 212 684-1814
Received on Friday, 27 August 1999 18:30:55 UTC

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