[uf-discuss] rel-tag ... or something more?

[Angus McIntyre]

I'm currently maintaining a blog about wine for a non-computer-savvy
relative:

   http://www.lovatstephen.com/

The blog postings - not yet using hAtom, but I hope to get that - contain
references to particular wines, grapes, winemakers, countries and
wine-growing regions. Ultimately, I'd like to pull these references out to
build an index of each type (so that visitors to the site could, for
instance, see all postings that referred to a particular grape).

So far, I've been simply marking these up with <span>, i.e.

   <span class="grape">Pinot Noir</span>

However, it occurs to me that there should be a more microformat-savvy way
to do this. My first thought is that rel-tag would be appropriate:

   <a href="/tags/grape/Pinot+Noir" rel="tag">Pinot Noir</a>
   <a href="/tags/wine/Yali+Gran+Reserva+2005" rel="tag">Gran Reserva
2005</a>
   <a href="/tags/region/France/Bordeaux" rel="tag">Bordeaux</a>

My custom index builder should be able to pull the necessary information
out of the tag path to build the index.

That looks simple enough and I think it's consistent with the intended
uses of rel-tag. However, I also wondered if there's a way to express
richer information. For instance, a sentence like:

      ... the Ridgeview Merret Bloomsbury 2003 (70% Chardonnay,
      23% Pinot Noir, 7% Pinot Meunier) ...

contains information about the relationship between a wine and the grapes
used in making it, which might be an interesting thing to extract and
represent in an index.

I'm not really proposing an entire microformat for writing about wine, as
that seems like a niche application. I'm just wondering if there's any
approved microformat-like way to express relations between concepts or
tags, so that knowledge could be encoded into a page in an extractable
format. Is there any way to express the idea that tag1 bears some relation
to tag2, where there can be arbitrarily many relations between arbitrarily
many tags? The idea of embedding a semantic network in an HTML page has a
certain twisted appeal ...

Angus