[uf-new] Microformats for hidden data

[Fiann O'Hagan]

Hi Tantek,

> 1. make up a poshformat and take care to NOT call it a microformat
> (because it isn't one, and you never intend to try to take it through
> the process)

No, that's not true. I still think there's a very good use case here
for a real microformat, although we have not yet explained it clearly
enough. Subject to community acceptance, I want to go back to square
one and go through the full process.

> As Scott has pointed out, it will be nearly impossible to make a
> microformat for invisible data given that the process has many steps
> requiring documentation/existence of visible data to mark up.

I was thinking about this last night, and realised that this is
critical. What precisely do you mean by "visible" in the context of
microformats?

On reflection, it's not the simple binary property that it might first
appear. I started by thinking that it means "rendered on the screen
when the page is loaded in a browser". But HTML meta tags for one do
not meet this criterion. Depending on your browser, you might see
something if you do File / Properties, but it's certainly not visible
to a casual end user.

What about tabbed content? For example on
http://docs.jquery.com/Core/jQuery the examples and source code appear
if you click the tab headings, but otherwise they are not displayed,
even though they are in the HTML of the page if you view source.

What about information that is visible only for certain media? If a
site has a print stylesheet that hides the nav bar in the printed
format, does that count as visible? What about if there is some
information like a permalink which is displayed only when the page is
printed, and not with the screen CSS?

What about microformat data which is hidden from view? For example,
search on Yahoo Local and you will see the business information in
hCard format, in visible text. Want to know the latitude and
longitude? It's in there too, but it is display:none, so you won't see
it unless you have some kind of microformat parser like Operator
installed in your browser. (Look for 'geo' in the source).
http://uk.local.yahoo.com/Somerset/Glastonbury/glastonbury/1003476909-e-21142.html

It's the final case which is most closely related to what I am
proposing here. They have information which is part of the page but it
is neither hidden metadata, nor is it rendered in a default view. It
is intended to be visible to a different audience than the casual end
user browsing the site.

I want to do the same thing, which is to add information to the page,
in such a way that it is accessible to humans looking at the source of
the page, and to people with the right parser in their browser, but is
not part of the view generally presented to end users.

If what Yahoo Local are doing is not an acceptable use of
microformats, then I accept that it's not the right approach for us
either. But in the world of mashups, scraping, screen readers and all
manner of different ways of consuming HTML, it seems like a very
artificial restriction.

Fiann