[microformats-discuss] Re: Educationg Others

Kevin Marks kmarks at technorati.com
Tue Oct 4 16:05:57 PDT 2005

On Oct 4, 2005, at 3:40 PM, Lisa Rein wrote:
> But first things first. RE: profiles. Then I will get back to  
> namespaces
> and/or Scott's elegant attempt at providing context for the different
> namespaces using span tags, etc. And demonstrating the need for a  
> unique
> ID (URI) for each. Which is our only hope...and, as we've already
> discussed, is required anyway by the XHTML/HTML specs...
> I don't understand how you would mix domain-specific markup without  
> some
> kind of mechanism for informing software about which is which.  
> Otherwise
> the different vocabularies have no real meaning to a software  
> application.
> (Context is everything when you're dealing with semantics. Otherwise,
> there are no semantics really :-)

I think I see where the misunderstanding is coming from here. We  
distinguish (not always clearly) between elemental microformats (such  
as rel="tag" or votelinks) and compound ones, such as hCard or hReview  
which can combine many elemental ones.

For rel="tag", the context is deliberately left vague, so it can be  
redefined by a containing microformat.

The Compound ones work by having a class name in the outer container  
defining the context, which is indeed like Scott's example.

here's where I explained it earlier:


and the example:

<div class="hreview"> <span class="version"  
style="display:none">0.2</span> <h2 class="summary"> Wonderful seafood,  
workmanlike ambience </h2> <abbr class="dtreviewed"  
title="20050722T1415-0700"> Jul 22, 2005 </abbr> by <span  
class="reviewer fn">Kevin Marks</span> <span class="type"  
style="display:none">business</span> <div class="item vcard"> <a  
href="http://www.philsfishmarket.com" class="url fn org">Phil's Fish  
Market</a> <div class="adr"> <div class="street-address">7600 Sandholdt  
Rd. </div> <span class="locality">Moss Landing</span>, <span  
class="region">CA</span> <span class="postal-code">95039</span> </div>  
<div class="tel">831-633-2152</div> </div> <blockquote  
class="description"><p> <abbr class="rating"  
title="5">&#x2605;&#x2605;&#x2605;&#x2605;&#x2605;</abbr> Phil's is  
tucked away in between the docks and the beach in <a  
href="http://technorati.com/tag/Moss+Landing" rel="tag">Moss  
Landing</a>, where it gets first pick of the <a  
href="http://en.wikipedia.org/wiki/fish" rel="tag">fish</a> landed  
there each day, and cooks up delicious fresh <a  
href="http://technorati.com/tag/seafood" rel="tag" >seafood</a> dishes  
that would cost 3 times as much in SF. Resolutely unostentatious, you  
order food by lining up at the cash register, and while you can sit <a  
href="http://en.wiktionary.org/wiki/outside" rel="tag">outside</a>, the  
seats face the power station opposite the front, rather than the beach  
at the back.</p></blockquote> </div>

The outer div with class "hreview" provides context for the tags.  
Technorati and other comprehensive blog indexers will pick up the  
'seafood','fish', 'outside' and 'Moss Landing' tags from that and  
associate them with this post, but a specialised service looking for  
reviews could see them in the context of the 'hreview' class, and use  
the more structured rating data to make more sense of it.

So the namespace issue collapses into choosing suitable unique names  
for these outer classes.
> I was going to ask if the different microformats be defined using  
> multiple
> profile attributes within the same HEAD element? But that seems really
> messy, and doesn't solve the problem of differentiating the markup  
> within
> the page. (I can't tell if it's allowed.)

As noted on the XMDP page, you can have multiple profiles listed in a  
single profile header.

> Would using multiple profile attributes even be allowed? And how would  
> a
> user agent able to differentiate between the different microformats if
> they all use "rel-tag" method?

Yes, by the containing context, as above.

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