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Re: null alt-text, spacers, etc. etc.

From: Wendy A Chisholm <wendy@w3.org>
Date: Wed, 05 Jan 2000 10:26:56 -0500
Message-Id: <4.2.0.58.20000105100258.00af97e0@localhost>
To: webmaster@dors.sailorsite.net
Cc: w3c-wai-er-ig@w3.org
Bruce,

Thank you for catching the errors in my draft.

The text should say:
"Valid:
IMG is the content of a link with text and the "alt" is null.  e.g.
<a href="foo.html"><IMG src="foo.gif" alt="">Please refer to foo</a> or 
alt=" ".

>Some of your examples for alt content for bullets and lines are counter 
>indicated.  There is no other way to say this but that <Q>alt="bullet"</Q> 
>and <Q>alt="horizontal rule"</Q> are just WRONG.  Perhaps these should 
>even be treated as suspicious?  ALTernative text should capture the 
>intent/function and not be solely pseudo-descriptive.  Using a value of 
>"---" for ALT is infinitely better than using "bar".  (Yes, the period 
>belongs inside the quotation mark, but don't you really prefer it when 
>technical documentation is not ambiguous?)

1. I did not use the example <Q>alt="horizontal rule"</Q> on the main 
page.  I did not modify the test pages.

2.  It is tricky to <em>only</em> suggest punctuation such as asterisk or 
underscore since oftentimes those characters are not read by screen readers 
because of a user preference to turn off punctuation.  Therefore, including 
what the screen reader might say instead would be better.

3. what is the function of a bullet that would be more appropriate for the 
alt-text.

4.  Note that is says,
<blockquote>If the author confirms that an image is a horizontal bar, 
suggest that the "alt" attribute value provide the function that the bar 
provides visually such as "end of page" or "navigation bar follows." If the 
author confirms that its purpose is decorative, suggest something simple 
like "bar."
</blockquote>

therefore we are pushing that if it has a function provide a functional 
equivalent.  Not all images have a function per se if they are purely 
decorational.


>I hate to bring this up, but since you make allowances for "one or more 
>spaces", do you have to do the same with &nbsp; ?

no, please note that &nbsp; is not allowed.
<blockquote>
Not allowed:
no "alt" attribute, e.g. <IMG src="foo.gif">
alt="&nbsp;"
</blockquote>


>I still think that the merits of a simple rule (<Q>alt="" is not 
>allowed</Q> -- we are discussing an accessibility perspective remember) 
>outweighs the need to use the empty string for content-free (decorative) 
>and spacer GIFs.  Using <Q>alt=" "</Q> would be okay for these -- and does 
>NOT cause the "hidden link" problem  on text-only UA (Lynx).  Your "treat 
>as suspicious" examples are otherwise good.  I don't think you can specify 
>what is "valid" (perhaps you should use "allowed" -- since we are not 
>testing for "validity" per se) because there is not way to automate a test 
>for "good and appropriate" alt content.  One can merely specify that which 
>definitely or possibly poor or inappropriate.

1.  the WCG group could not come to consensus to determine which is 
<em>the</em> way to go: a space or a null.  Therefore, we compromised and 
said, "leave it up to the author."  You can look through the WCG archives 
[1-3] from the last few months to see the ongoing thread.

2. I apologize that I left out a major piece of our decision in this draft: 
We should encourage people to use style sheets rather than images that 
require a space or null alt text.  i will modify my draft to reflect 
this.  Refer to discussions in [4].

relevant threads on the WCG list:
[1] http://lists.w3.org/Archives/Public/w3c-wai-gl/1999OctDec/0043.html
[2] http://lists.w3.org/Archives/Public/w3c-wai-gl/1999OctDec/0024.html
[3] http://lists.w3.org/Archives/Public/w3c-wai-gl/1999OctDec/0171.html

relevant thread on the ER-IG list:
[4] http://lists.w3.org/Archives/Public/w3c-wai-er-ig/1999Dec/0008.html

--wendy
--
wendy a chisholm
world wide web consortium
web accessibility initiative
madison, wi usa
tel: +1 608 663 6346
/--
Received on Wednesday, 5 January 2000 10:27:37 GMT

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