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Re: Guideline 1 in The evaluation techniques document

From: Nir Dagan <nir@nirdagan.com>
Date: Thu, 24 Jun 1999 16:22:45 -0400 (EDT)
To: Al Gilman <asgilman@iamdigex.net>
cc: w3c-wai-er-ig@w3.org
Message-ID: <Pine.BSF.4.02A.9906241620540.23651-100000@dhaame.pair.com>
Generally null is not white space but the specs say that leading and
trailing white space in CDATA attribute values can be egnored by user
agents. E.g., "myval" may be treated as " myval "
Regards,

Nir Dagan

http://www.nirdagan.com
mailto:nir@nirdagan.com

"There is nothing quite so practical as a good theory." 
-- A. Einstein

On Thu, 24 Jun 1999, Al Gilman wrote:

> At 11:56 AM 6/24/99 +0300, Nir Dagan wrote:
> >I realy do not understand the idea behind:
> >
> >Not allowed - NULL ALT value (ALT="")
> >Allowed - ALT value of 1 or more spaces (ALT=" ")
> >
> >Both from a semantic/logical point of view and HTML specification 
> >these are quite the same thing.
> 
> Not quite.  You are ignoring the way logic depends on lexical analysis or
> the recognition of word boundaries.  "Lay out" is a verb while "layout" is
> a noun.  The logic depends on the lexing.  Whitespace is not guaranteed to
> be logically without effect.  Null is not whitespace, space is.  There are
> enough situations where this introduces a semantic difference.
> 
> In the HTML specification it merely warns that some user agents may ignore
> whitespace in certain circumstances.  I do not believe that you will find
> this carried forward in either the work on XML normalisation nor in the
> Internet-Draft from DRUMS updating RFC 822.  What I am saying is that the
> best thinking on this issue is that a null string and linear whitespace are
> logically different, a distinction that must be preserved.
> 
> Al
> 
> >
> >My major reservation with this guideline is that there may be out there 
> >many people who took the effort to write accessible pages with alt=""
> >where appropriate, and now we tell them to revise their pages, without
> >any reason whatsoever.
> >
> >Regards,
> >Nir Dagan
> >
> >http://www.nirdagan.com
> >mailto:nir@nirdagan.com
> >tel:+972-2-588-3143
> >
> >"There is nothing quite so practical as a good theory."
> >-- A. Einstein
> > 
> 
Received on Thursday, 24 June 1999 16:22:48 GMT

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