[microformats-discuss] RFC: Thoughts on Video and Audio Microformats

Dr. Ernie Prabhakar drernie at opendarwin.org
Tue Oct 18 13:10:36 PDT 2005

Hi Charles,

On Oct 18, 2005, at 12:50 PM, Charles Iliya Krempeaux wrote:
> I like to get some clarification here.  When you say "The one concern
> I have with URNs... is that they are pretty much opaque".  Who are you
> talking about?  Opaque to who?

Me. :-) Sorry, "opaque" may not be the best word, so let me explain.  
When I see:


I have no idea what that means, or whether it is the same or  
different than the other URNs you list (without doing a detailed  

Compare that with an actual URL, which tells me something about the  
host and (usually) has human-readable names.

> To the person scripting the HTML code, the "urn" attribute is no more
> opaque than the "rev" or "rel" attribute.  If we consider that using
> "rel" and "rev" is good practice (for Microformats) then I can't see
> why "urn" wouldn't be acceptable also.  (Well, if it was still part of
> the latest HTML spec, that is.)

To be fair, if URNs had gotten picked up, may these uuid's may have  
seemed more intuitive as a means of identification.   But frankly, I  
still think it would be clearer to use:


That is just as unique, but far more human-readable. That is what I  
meant by 'opaque', even if my word choice was poor.

That is why I consider 'rel="proflie"' more transparent -- it  
actually means something to a human, even if the semantics are  
perhaps not as clear.

> And to the person viewing the HTML code,.... Just so I understand
> things, what makes "title" and "class" non-opaque?  OK, "title" will
> popup up a "tooltip" (at least in my browser).  But "class" is only
> visible when you apply a "style" to it.  But there is nothing stopping
> you from applying styles based on the "urn" attribute (or any other
> attribute).  (I've seen some nice examples of applying styles based on
> the "rel" attribute to find XFN usage.)

I completely agree that such things are *possible*.  However, this  
gets into the microformat zen of whether they are "natural."   To me  
at least, it seems perfectly natural to say:
	a) All pick lists (where I'm choosing media) should use the  
'pickList' className
	b) These picklists should be styled with a blue background

That, to me, is a natural semantic mapping.  Yes, you could do the  
same thing with 'urns', but it would be less obvious.   Its a subtle  
distinction, but a crucial part of "microformat zen."

> I think that many people only use the "class" attribute to apply
> style.  And it has little to do with (usable) semantics.

Absolutely.   The question is, is that a good thing or not?  What I  
might call the "strong microformat" position is that CSS classes  
should *always* represent semantic content -- though most people even  
on this list might not go _that_ far. :-)

> I think we need to consider how Microformats are going to be used...
>     #1 Are they something we expect people to script by hand?
>     #2 Or are they something people are going to generate with "code
> builders" and embed into webpages?
> (Certainly if #1 is our objective then #2 can certainly be met too
> without any conflict to #1.  But anyways.)

It is absolutely to do both. In fact, this is almost a microformat  

"Tools work best when they mimic what human beings do naturally.  Not  
vice versa."
-- Dr. Ernie, 10/18/2005 (for the quote board :-)

> If it is #2, then we should NOT use "urn".  But we should also note
> use "rel" or "rev".
> But it is #1, then attributes seems acceptable.  Or am I missing  
> something?

I think you're missing the *cultural* difference in the way people  
use "rel" with "href" to represent a human-meaningful content.  This  
is all about human perceptions, not Turing equivalent.

> (Which is where I think you are coming from.  Although Microformats
> like hcard and hcalerdar have more "structure" to them... in the same
> way that <table> has more structure.)

> Yes,... I think I understand.  You are using the "class" attribute to
> "invent" new tags.  (Is that correct?)

Yes, absolutely.  If there's an appropriate XHTML construct which  
plausibly *does* carry the correct semantics, we ought to use that.   
But if not, we should define that specific semantic as a new class  
name, rather than (ab)using an existing tag inappropriately.

Hope this helps,
- Ernie P.
Ernest N. Prabhakar, Ph.D. <drernie at opendarwin.org>
Ex-Physicist, Marketing Weenie, and Dilettante Hacker
Probe-Hacker blog: http://www.opendarwin.org/~drernie/

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