[whatwg] Web Forms 2.0 Feedback

James Graham jg307 at cam.ac.uk
Thu Jan 6 06:57:57 PST 2005


Matthew Thomas wrote:

>
> Again, I know that <sup> and <sub> are (almost always) used to mean  
> something, just like <b> and <i> are. But again, just as with <b> and  
> <i>, *a computer can't tell what you mean*. When you use <sup> do you  
> mean exponent, or footnote, or moment, or transpose of a matrix, or  
> something else? Purely from the markup, a computer can't tell, 
> because  <sup> is presentational. When you use <sub> do you mean 
> number of atoms  in (that part of the structure of) the molecule, or 
> variable instance,  or logarithm base, or matrix index, or something 
> else? Purely from the  markup, a computer can't tell, because <sub> is 
> presentational.

Of course the same is true with, say <li>. A computer can't tell whether 
you mean a list of shopping, or a list or a list of links, or a list of 
people who have offeneded you in the past month, or ... Purely from the 
markup you can't tell yet few people claim that lists are presentational.

HTML by it's nature has weak semantics. That means that elements should 
conatin some information ("this is a list not a set of paragraphs", 
"these characters are superscripted and so not part of a word") that the 
UA can use, as far as it is able, to provide an appropriate interface to 
the document. It does not mean that every element has to have a 
precidely defined meaning in the sense that you criticise <sup> and 
<sub> for lacking. To do better you need highly domian-specific langauges.




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