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Re: Error Message Feedback

From: Jukka K. Korpela <jkorpela@cs.tut.fi>
Date: Wed, 4 Oct 2006 20:31:20 +0300 (EEST)
To: Rick Stanley <rstanley@rsiny.com>
cc: www-validator@w3.org
Message-ID: <Pine.GSO.4.64.0610042019430.7019@mustatilhi.cs.tut.fi>

On Wed, 4 Oct 2006, Rick Stanley wrote:

> Warning Line 5 column 44:
> character "<" is the first character of a delimiter but occurred as 
> data.
>  <meta name="revised" content="Time-stamp: <2006-10-03 22:54:38 rick> " />

The warning is misleading. The character "<" is just a data character when 
it appears inside an attribute value. There it is not a delimiter of any 
kind.

The validator wants to say, informatively, that it is still recommendable 
to represent it as "&lt;". Don't ask me why. I guess someone has observed 
some browser or some other software getting the rules wrong.

> This is a emacs editor Timestamp.  Since I can only use 'Time-stamp: "'
> ", or 'Time-stamp: <>' I used the latter since it needed to go inside
> quotes.

I guess Emacs may use the timestamp for its internal business, expecting 
to find it in a particular notation, so I would _not_ change the "<" to 
"&lt;", even though any correct SGML or XML parser should still get it 
right. We can't expect text editors to do correct parsing.

> Should the validator notice what is inside of quotes,

Yes, as regards to entity and character references. No, as regards to 
anything else, including "<" - though a validator may have a second job as 
a heuristic checker, and in that role it may notice whatever it likes.

> especially inside of a meta tag?

That's irrelevant in validation. An attribute value declared as CDATA 
shall be processed by the same rules, no matter what the element name is.

> The '<', and '>' characters are NOT
> deliminators INSIDE of a quoted string.

Inside an attribute value, that is. That's the key. Quotation marks or 
apostrophes are needed to delimit the attribute value (at least when you 
have "<" inside it, and always in XHTML), but that's secondary.

> I don't think this should invoke a warning.

I tend to agree. Is there any tangible benefit from the warning? Does it 
help people to create practically more robust documents? I don't think so, 
unless there's some relevant software still in uses that parses attribute 
values all wrong. Besides, even a program incorrectly looks for tag open 
characters, i.e. "<", inside an attribute value, it most likely treats 
them as data characters when followed by a digit and not a letter.

At least the warning, if retained, should be rephrased, e.g. simply as

"Warning: character < used as data character"

-- 
Jukka "Yucca" Korpela, http://www.cs.tut.fi/~jkorpela/
Received on Wednesday, 4 October 2006 17:31:40 GMT

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