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Re: Complex Table Examples

From: Lachlan Hunt <lachlan.hunt@lachy.id.au>
Date: Sun, 13 May 2007 22:48:11 +1000
Message-ID: <4647090B.9050602@lachy.id.au>
To: "Patrick H. Lauke" <redux@splintered.co.uk>
CC: www-html@w3.org

Firstly, why is it that you chose to change the subject back to 
presentational elements, instead of being productive and focussing the 
the table headers issue?

I've already asked 3 times for examples to be provided that would 
support the addition of the headers attribute (and provided some 
myself), trying to help you strengthen you case for adding it, but each 
time you have bypassed question entirely.  I will not ask again, but I 
would appreciate your cooperation this time.

Patrick H. Lauke wrote:
> Lachlan Hunt wrote:
>> No, that's backwards.  Nothing gets added or retained without some 
>> evidence that it's needed.  Otherwise, you could use that argument to 
>> get us show why the <foo> element isn't needed, instead having the 
>> ones who asked for it explain why it is.
> 
> Which seems to me what's happening with refinements for <b>, <i>, <sup>, 
> <sub> etc

No, that is not what is happening with those elements.  They do have 
many valid use cases.  <b> and <i> were thoroughly explained in the 
recent threads, so I will not go into them again.

http://lachy.id.au/log/2007/05/b-and-i

<sub> and <sup> have valid use cases too.

* Simple mathematical expressions
   e.g. <var>E</var> = <var>m</var><var>c<sup>2</sup></var>
        <var>x<sub>1</sub></var>
* Chemical compunds. e.g. H<sub>2</sub>O
* Footnote references
* etc.

Even the the spec makes use of <sub> in several places for good reasons. 
  See, for example, this algorithm.

http://www.whatwg.org/specs/web-apps/current-work/#header-and-data-cell-semantics

Their names may come from the typographical conventions, but those 
conventions are used for very specific reasons.  It's quite reasonable, 
in a general purpose markup language like HTML, to provide simple 
elements that cover those cases reasonably well, rather than requiring 
specific elements for each individual case.

Like <b> and <i>, the specific semantics of <sub> and <sup> can be 
determined by the reader from the context of their use.  Omitting them 
or replacing them with something like <span> would be far less semanitic 
and less useful for users.

If we were to drop them from HTML, we'd create a problem.  How would all 
of those use cases (including ones I didn't list) be marked up?  <sub> 
and <sup> already solve that problem reasonably well, there's no reason 
to replace them with something new.

If it can be shown that such context sensitive semantics is a problem in 
practice, then that may be a reason to provide a way to more 
specifically refine the semantics (e.g. x<sup type="math">2</sup>).  But 
there hasn't yet been any evidence to show that it is a problem, and so 
nothing would be solved by doing that.

-- 
Lachlan Hunt
http://lachy.id.au/
Received on Sunday, 13 May 2007 12:48:28 GMT

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