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Whitespace (and null) ALT niceties

From: Al Gilman <asgilman@access.digex.net>
Date: Tue, 17 Nov 1998 11:22:42 -0500 (EST)
Message-Id: <199811171622.LAA03255@access2.digex.net>
To: w3c-wai-ua@w3.org, w3c-wai-gl@w3.org
Cc: w3c-wai-er-ig@w3.org

If WAI-UA would be willing to add an note to its HTML4.0 implementation
guidance, then WAI-GL can drop an ugly note in the "deprecated example"
subclause dealing with the case where ALT=" " is appropriate.

Al

to follow up on what Chris Ridpath said:

> Just to be clear...
> 
> Null Alt text (ALT="") should be used when the image is used to position the
> next element further down on the page. This works something like a
> carriage-return/line feed.
> 
> Space Alt text (ALT="  ") should be used when the image is used to position
                       ^^--- prefer just one <SPACE>, not two (typo?) 

> the next element further across the line. This works like the space key.
> 
> This is what I get from the examples. Right, wrong?

Well, I don't think that the null ALT is only used for images
which emulate <BR> but also for those which are used for
positioning left-to-right in the visual layout.  Any image whose
description would be "spacer-image" may be annotated with ALT=""
as I read the technique.  This sits across a rift in preferences
between GUI implementation of non-loaded images and non-GUI
users.

That is what I get from the examples and [just my reading] a
telecon that discussed this point.  

By the way, the author guidelines go to far in noting that
attribute-reading may ignore leading and trailing whitespace.
This does not imply that a single space character may be ignored.
A single space character does not satisfy the definition of
"leading or trailing whitespace" in the terms of this warning.
There is nothing that it is leading or trailing.  It would be
entirely appropriate for the UA guidelines to clarify this in its
section on how to implement HTML4.0.  The point of what the HTML
document says is that it is reasonable for browsers to treat ("
token ") as synonymous with ("token").  When the attribute is
entirely composed of linear whitespace characters, some linear
whitespace must survive any approximation.

A formal style rule could be something like "if the ALT value
contains only linear whitespace, and the element appears in an
inline flow, then the rendering agent shall ensure that linear
whitespace occurs between the two surrounding flow objects."  But
real browsers will just copy the ALT string into the text flow
and be done.  Consider how BR has been handled in practice.

Al
> 
> >Please see
> >
> > <http://www.w3.org/WAI/GL/wai-gl-techniques-19980918.html#spacer-images>
> >
> >for the current draft guidance on this question.  This says that
> >null alt text is appropriate under certain circumstances.  It
> >remains to be seen whether a particular heuristic will recognize
> >these circumstances accurately or not.
> >
> >Al
> >
> >to follow up on what Michael Vorburger said:
> >
> >> Chris and others interested in the matter,
> >>
> >>    I agree everything SHOULD have a purpose, but in the "real-world" case
> of
> >> a 1x20 transparent GIF for spacing, I really cannot see the purpose of
> >> (automatically) adding any other ALT than ALT="". What could be the
> interest
> >> of a text-only user to see ALT="decoration image" for this case???
> >>     -----Original Message-----
> >>     From: Chris Ridpath [mailto:chris.ridpath@utoronto.ca]
> >>     Sent: Monday, November 16, 1998 3:11 PM
> >>     To: mike
> >>     Subject: Re: Automatic Alt Text Generation
> >>
> >>
> >>     Michael,
> >>
> >>     I'm looking forward to looking at the specs for your semester project
> >> next week. Please let me know when they're available.
> >>
> >>     It seems to me that everything in the document has a purpose. The
> >> purpose of the decorative image you describe is decoration
> (ALT="decoration
> >> image"). If you allow ALT="" then the Lynxx user does not know if the
> >> document creator forgot to put in Alt text or it is one of your
> decoration
> >> images.
> >>
> >>     Cheers,
> >>     Chris
> >>
> >>         -----Original Message-----
> >>         From: Michael Vorburger <mike@vorburger.ch>
> >>         To: Chris Ridpath <chris.ridpath@utoronto.ca>
> >>         Date: November 14, 1998 10:12 AM
> >>         Subject: RE: Automatic Alt Text Generation
> >>
> >>
> >>         Chris
> >>
> >>           tx for pointing me to the WAI-AU mailing list, which I did not
> >> know before. I read the web archive of the ALT text discussion. My
> ALTifier
> >> tool is going to set ALT="" for an IMG which clearly is "decorative
> only",
> >> like a transparent 1x10 GIF etc. I think this is good and cannot see the
> >> problem with this. I did incorporate the relevant parts of Daniel's
> >> text-equiv page into my project.
> >>
> >>            I hope to publish the full specification of my semester
> project
> >> next week and am looking forward to any comments from you and the others
> >> from the list! We will probably also talk about it the next phone
> >> conference.
> >>
> >>         Regards,
> >>         Michael
> >>             -----Original Message-----
> >>             From: Chris Ridpath [mailto:chris.ridpath@utoronto.ca]
> >>             Sent: Friday, November 06, 1998 3:56 PM
> >>             To: mike
> >>             Subject: Re: Automatic Alt Text Generation
> >>
> >>
> >>             Michael,
> >>
> >>             Daniel has a page with several ideas concerning the automatic
> >> creation of Alt text. A couple of the ideas were discussed in the phone
> >> conversation but I haven't seen the minutes yet. Daniels ideas can be
> found
> >> at:
> >>
> >>             http://www.w3.org/WAI/ER/text-equiv.htm
> >>
> >>             There has been some discussion about the generation of
> automatic
> >> Alt text on the w3c-wai-au@w3.org list.
> >>
> >>             The current authoring tool guidelines can be found at:
> >>
> >>             http://www.w3.org/WAI/UA/WD-WAI-USERAGENT-19981030/
> >>
> >>             They haven't been updated to include the suggestions for
> >> automatic Alt text generation yet.
> >>
> >>             Hope this helps,
> >>             Chris
> >>
> >>                 -----Original Message-----
> >>                 From: Michael Vorburger <mike@vorburger.ch>
> >>                 To: Chris Ridpath <chris.ridpath@utoronto.ca>
> >>                 Date: November 6, 1998 5:22 AM
> >>                 Subject: RE: Automatic Alt Text Generation
> >>
> >>
> >>                 Hello Chris
> >>
> >>                   I was unfortunately not able to participate in the
> conf.
> >> call this time. I am very interested in the suggestions for Automatic ALT
> >> Text generation. Could you maybe send them to me by private mail, or
> point
> >> the URL of the authoring tool guidelines if already published? I will be
> >> happy to comment on them.
> >>
> >>                 Tx,
> >>                 Michael
> >>                     -----Original Message-----
> >>                     From: w3c-wai-er-ig-request@w3.org
> >> [mailto:w3c-wai-er-ig-request@w3.org]On Behalf Of Chris Ridpath
> >>                     Sent: Thursday, November 05, 1998 9:58 PM
> >>                     To: w3c-wai-er-ig
> >>                     Subject: Automatic Alt Text Generation
> >>
> >>
> >>                     I've made a couple of suggestions for inclusion in
> the
> >> authoring tool guidelines as we discussed in the recent conference call.
> >> Please let me know if you have any comments.
> >>
> >>
> >
> >[text/html is unsupported, treating like TEXT/PLAIN]
> >
> >[Charset iso-8859-1 unsupported, filtering to ASCII...]
> >> <!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">
> >> <HTML>
> >> <HEAD>
> >>
> >> <META content=text/html;charset=iso-8859-1
> http-equiv=Content-Type><!DOCTYPE HTML PUBLIC "-//W3C//DTD W3
> HTML//EN"><!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">
> >> <META content='"MSHTML 4.72.2106.6"' name=GENERATOR>
> >> </HEAD>
> >> <BODY bgColor=#fffbf0>
> >> <DIV><SPAN class=600510923-16111998><FONT color=#0000ff face=Arial
> size=2>Chris
> >> and others interested in the matter,</FONT></SPAN></DIV>
> >> <DIV><SPAN class=600510923-16111998><FONT color=#0000ff face=Arial
> >> size=2></FONT></SPAN>&nbsp;</DIV>
> >> <DIV><SPAN class=600510923-16111998><FONT color=#0000ff face=Arial
> >> size=2>&nbsp;&nbsp; I agree everything SHOULD have a purpose, but in the
> >> &quot;real-world&quot; case of a 1x20 transparent GIF for spacing, I
> really
> >> cannot see the purpose of (automatically) adding any other ALT than
> >> ALT=&quot;&quot;. What could be the interest of a text-only user to see
> >> ALT=&quot;decoration image&quot; for this case???</FONT></SPAN></DIV>
> >> <BLOCKQUOTE
> >> style="BORDER-LEFT: #0000ff solid 2px; MARGIN-LEFT: 5px; PADDING-LEFT:
> 5px">
> >>     <DIV class=OutlookMessageHeader><FONT face="Times New Roman"
> >>     size=2>-----Original Message-----<BR><B>From:</B> Chris Ridpath
> >>     [mailto:chris.ridpath@utoronto.ca]<BR><B>Sent:</B> Monday, November
> 16, 1998
> >>     3:11 PM<BR><B>To:</B> mike<BR><B>Subject:</B> Re: Automatic Alt Text
> >>     Generation<BR><BR></FONT></DIV>
> >>     <DIV><FONT color=#000000 size=2>Michael,</FONT></DIV>
> >>     <DIV><FONT color=#000000 size=2></FONT>&nbsp;</DIV>
> >>     <DIV><FONT size=2>I'm looking forward to looking at the specs for
> your
> >>     semester project next week. Please let me know when they're
> >>     available.</FONT></DIV>
> >>     <DIV><FONT size=2></FONT>&nbsp;</DIV>
> >>     <DIV><FONT size=2>It seems to me that everything in the document has
> a
> >>     purpose. The purpose of the decorative image you describe is
> decoration
> >>     (ALT=&quot;decoration image&quot;). If you allow ALT=&quot;&quot;
> then the
> >>     Lynxx user does not know if the document creator forgot to put in Alt
> text
> >>     or it is one of your decoration images.</FONT></DIV>
> >>     <DIV><FONT size=2></FONT>&nbsp;</DIV>
> >>     <DIV><FONT color=#000000 size=2>Cheers,</FONT></DIV>
> >>     <DIV><FONT color=#000000 size=2></FONT><FONT
> size=2>Chris</FONT></DIV>
> >>     <DIV>&nbsp;</DIV>
> >>     <BLOCKQUOTE
> >>     style="BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px;
> PADDING-LEFT: 5px">
> >>         <DIV><FONT face=Arial size=2><B>-----Original
> >>         Message-----</B><BR><B>From: </B>Michael Vorburger &lt;<A
> >>
> href="mailto:mike@vorburger.ch">mike@vorburger.ch</A>&gt;<BR><B>To:
> >>         </B>Chris Ridpath &lt;<A
> >>
> href="mailto:chris.ridpath@utoronto.ca">chris.ridpath@utoronto.ca</A>&gt;<BR
> ><B>Date:
> >>         </B>November 14, 1998 10:12 AM<BR><B>Subject: </B>RE: Automatic
> Alt Text
> >>         Generation<BR><BR></DIV></FONT>
> >>         <DIV><SPAN class=540340715-14111998><FONT color=#0000ff
> face=Arial
> >>         size=2>Chris</FONT></SPAN></DIV>
> >>         <DIV><SPAN class=540340715-14111998><FONT color=#0000ff
> face=Arial
> >>         size=2></FONT></SPAN>&nbsp;</DIV>
> >>         <DIV><SPAN class=540340715-14111998><FONT color=#0000ff
> face=Arial
> >>         size=2>&nbsp; tx for pointing me to the WAI-AU mailing list,
> which I did
> >>         not know before. I read the web archive of the ALT text
> discussion. My
> >>         ALTifier tool is going to set ALT=&quot;&quot; for an IMG which
> clearly
> >>         is &quot;decorative only&quot;, like a transparent 1x10 GIF etc.
> I think
> >>         this is good and cannot see the problem with this. I did
> incorporate the
> >>         relevant parts of Daniel's text-equiv page into my
> >>         project.</FONT></SPAN></DIV>
> >>         <DIV><SPAN class=540340715-14111998><FONT color=#0000ff
> face=Arial
> >>         size=2></FONT></SPAN>&nbsp;</DIV>
> >>         <DIV><SPAN class=540340715-14111998><FONT color=#0000ff
> face=Arial
> >>         size=2>&nbsp;&nbsp; I hope to publish the full specification of
> my
> >>         semester project next week and am looking forward to any comments
> from
> >>         you and the others from the list! We will probably also talk
> about it
> >>         the next phone conference.</FONT></SPAN></DIV>
> >>         <DIV><SPAN class=540340715-14111998><FONT color=#0000ff
> face=Arial
> >>         size=2></FONT></SPAN>&nbsp;</DIV>
> >>         <DIV><SPAN class=540340715-14111998><FONT color=#0000ff
> face=Arial
> >>         size=2>Regards,</FONT></SPAN></DIV>
> >>         <DIV><SPAN class=540340715-14111998><FONT color=#0000ff
> face=Arial
> >>         size=2></FONT></SPAN><SPAN class=540340715-14111998><FONT
> color=#0000ff
> >>         face=Arial size=2>Michael</FONT></SPAN></DIV>
> >>         <BLOCKQUOTE
> >>         style="BORDER-LEFT: #0000ff solid 2px; MARGIN-LEFT: 5px;
> PADDING-LEFT: 5px">
> >>             <DIV class=OutlookMessageHeader><FONT face="Times New Roman"
> >>             size=2>-----Original Message-----<BR><B>From:</B> Chris
> Ridpath [<A
> >>
> href="mailto:chris.ridpath@utoronto.ca">mailto:chris.ridpath@utoronto.ca</A>
> ]<BR><B>Sent:</B>
> >>             Friday, November 06, 1998 3:56 PM<BR><B>To:</B>
> >>             mike<BR><B>Subject:</B> Re: Automatic Alt Text
> >>             Generation<BR><BR></FONT></DIV>
> >>             <DIV><FONT color=#000000 size=2>Michael,</FONT></DIV>
> >>             <DIV><FONT color=#000000 size=2></FONT>&nbsp;</DIV>
> >>             <DIV><FONT size=2>Daniel has a page with several ideas
> concerning
> >>             the automatic creation of Alt text. A couple of the ideas
> were
> >>             discussed in the phone conversation but I haven't seen the
> minutes
> >>             yet. Daniels ideas can be found at:</FONT></DIV>
> >>             <DIV><FONT size=2></FONT>&nbsp;</DIV>
> >>             <DIV><A
> >>
> href="http://www.w3.org/WAI/ER/text-equiv.htm">http://www.w3.org/WAI/ER/text
> -equiv.htm</A></DIV>
> >>             <DIV>&nbsp;</DIV>
> >>             <DIV><FONT color=#000000 size=2>There has been some
> discussion about
> >>             the generation of automatic Alt text on the <A
> >>             href="mailto:w3c-wai-au@w3.org">w3c-wai-au@w3.org</A>
> >>             list.</FONT></DIV>
> >>             <DIV><FONT color=#000000 size=2></FONT>&nbsp;</DIV>
> >>             <DIV><FONT size=2>The current authoring tool guidelines can
> be found
> >>             at:</FONT></DIV>
> >>             <DIV><FONT size=2></FONT>&nbsp;</DIV>
> >>             <DIV><FONT size=2><A
> >>
> href="http://www.w3.org/WAI/UA/WD-WAI-USERAGENT-19981030/">http://www.w3.org
> /WAI/UA/WD-WAI-USERAGENT-19981030/</A></FONT></DIV>
> >>             <DIV><FONT size=2></FONT>&nbsp;</DIV>
> >>             <DIV><FONT color=#000000 size=2>They haven't been updated to
> include
> >>             the suggestions for automatic Alt text generation
> yet.</FONT></DIV>
> >>             <DIV><FONT color=#000000 size=2></FONT>&nbsp;</DIV>
> >>             <DIV><FONT size=2>Hope this helps,</FONT></DIV>
> >>             <DIV><FONT size=2>Chris</FONT></DIV>
> >>             <DIV><FONT size=2></FONT>&nbsp;</DIV>
> >>             <BLOCKQUOTE
> >>             style="BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px;
> PADDING-LEFT: 5px">
> >>                 <DIV><FONT face=Arial size=2><B>-----Original
> >>                 Message-----</B><BR><B>From: </B>Michael Vorburger &lt;<A
> >>
> href="mailto:mike@vorburger.ch">mike@vorburger.ch</A>&gt;<BR><B>To:
> >>                 </B>Chris Ridpath &lt;<A
> >>
> href="mailto:chris.ridpath@utoronto.ca">chris.ridpath@utoronto.ca</A>&gt;<BR
> ><B>Date:
> >>                 </B>November 6, 1998 5:22 AM<BR><B>Subject: </B>RE:
> Automatic
> >>                 Alt Text Generation<BR><BR></DIV></FONT>
> >>                 <DIV><SPAN class=670495209-06111998><FONT color=#0000ff
> >>                 face=Arial size=2>Hello Chris</FONT></SPAN></DIV>
> >>                 <DIV><SPAN class=670495209-06111998><FONT color=#0000ff
> >>                 face=Arial size=2></FONT></SPAN>&nbsp;</DIV>
> >>                 <DIV><SPAN class=670495209-06111998><FONT color=#0000ff
> >>                 face=Arial size=2>&nbsp; I was unfortunately not able to
> >>                 participate in the conf. call this time. I am very
> interested in
> >>                 the suggestions for Automatic ALT Text generation. Could
> you
> >>                 maybe send them to me by private mail, or point the URL
> of the
> >>                 authoring tool guidelines if already published? I will be
> happy
> >>                 to comment on them.</FONT></SPAN></DIV>
> >>                 <DIV><SPAN class=670495209-06111998><FONT color=#0000ff
> >>                 face=Arial size=2></FONT></SPAN>&nbsp;</DIV>
> >>                 <DIV><SPAN class=670495209-06111998><FONT color=#0000ff
> >>                 face=Arial size=2>Tx,</FONT></SPAN></DIV>
> >>                 <DIV><SPAN class=670495209-06111998><FONT color=#0000ff
> >>                 face=Arial size=2></FONT></SPAN><SPAN
> >>                 class=670495209-06111998><FONT color=#0000ff face=Arial
> >>                 size=2>Michael</FONT></SPAN></DIV>
> >>                 <BLOCKQUOTE
> >>                 style="BORDER-LEFT: #0000ff solid 2px; MARGIN-LEFT: 5px;
> PADDING-LEFT: 5px">
> >>                     <DIV class=OutlookMessageHeader><FONT face="Times New
> Roman"
> >>                     size=2>-----Original Message-----<BR><B>From:</B>
> >>                     w3c-wai-er-ig-request@w3.org
> >>                     [mailto:w3c-wai-er-ig-request@w3.org]<B>On Behalf
> Of</B>
> >>                     Chris Ridpath<BR><B>Sent:</B> Thursday, November 05,
> 1998
> >>                     9:58 PM<BR><B>To:</B>
> w3c-wai-er-ig<BR><B>Subject:</B>
> >>                     Automatic Alt Text Generation<BR><BR></FONT></DIV>
> >>                     <DIV>
> >>                     <DIV><FONT color=#000000 size=2>
> >>                     <DIV><FONT color=#000000 size=2></FONT>I've made a
> couple of
> >>                     suggestions for inclusion in the authoring tool
> guidelines
> >>                     as we discussed in the recent conference call. Please
> let me
> >>                     know if you have any comments.</DIV>
> >>                     <DIV>&nbsp;</DIV>
> >>
> <DIV>&nbsp;</DIV></FONT></DIV></DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE><
> /BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
> >> <HTML><BR>----<BR></HTML>Michael Vorburger <mike@vorburger.ch> &
> <michael.vorburger@epfl.ch><BR>WEBMASTERS & FrontPage users, check out my
> cool webtool at:<BR>http://www.vorburger.ch/kissfp
> >
> 
Received on Tuesday, 17 November 1998 11:21:42 GMT

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