[whatwg] Add 'type' attribute to <mark>

[Pentasis]

>> Yes, but this is a theoretical explanation that does not provide a
>> consistent, practical solution.
>
> I don't understand why these solutions aren't consistent or practical.

First of all, the spec admits it itself:
"HTML does not have a dedicated mechanism for marking up footnotes. Here are 
the recommended alternatives."
Alternatives are not real mechanisms.

It gives us the option of using the title attribute (which has no mechanism 
of expansion and we cannot group them).
Then it gives us the a element solution, which is how it is already done in 
most cases but leaves much to be desired (there are plenty of articles about 
it on the web).
And last it tells us we can use the aside element. But in this example there 
is no *direct* relation to the actual word/phrase we put in the aside. It 
also gives us -again- no direct mechanism of expansion and no way of 
grouping footnotes/sidenotes.

Now, I am perfectly happy for this spec not to provide a footnote construct, 
but in that case I would strongly suggest removing these alternatives and 
simply say it should be resolved using scripting (which has much more 
flexibility) or not say anything at all about it.

>> Like I said before, I think class (and id) should be reserved for
>> styling and not be content/semantic related at all.
>
> I'm afraid that's not what class and id are for, they are entirely
> intended as a way for authors to annotate their semantics in more detail.
>
> You should never use class (or id) for specifically stylistic reasons. You
> should use class to annotate the semantics, and then separately use the
> style sheets to hook onto your annotated semantics to get the style you
> want in more fine grained detail than the elements allow.
>
> This is why values like class="big" or class="green" are bad, but values
> like class="footnote" or class="user-search-terms" are fine.

I will agree to the fact that this is the general consensus. And I have been 
doing it like that for a long time as well. But I will leave it at that, 
this is an entirely different discussion which has nothing to do with 
footnotes and I apologize for bringing it up.

Bert