microformats2-brainstorming

Brainstorming experimental / undeveloped / rejected ideas for microformats-2.

further simplifications

more on allow root class name only

This has been stable for a while, see:

• microformats-2-implied-properties

adopt itemref

There many existing real-world use-cases where either:

• several microformats in a page want to share some common data without repeating it.
  • e.g. a page about a product with multiple reviews of that product (very common, products sites, Amazon/CNET et al, review aggregators, Yelp et al)
  • e.g. representing the author of multiple hAtom entries on a page. Currently this is possible with the <address class="hcard"> optimisation, which would be rendered obsolete by the proposed new generic parsing rules.
• a microformat in a page needs to incorporate information spread across different parts of a page, without assigning the entire page to that microformat

The include-pattern provides the necessary functionality for existing microformats (1.0).

For 2.0 it may be reasonable to simply re-use the nice itemref attribute from microdata, with identical/analogous functionality.

That is, when present on the root element of a microformat, the itemref attribute provides a space separated list of ids of elements in the document which are then incorporated as children of the microformat, before its actual children in the document. This is a simple coarse summary of course, and the actual itemref inclusion algorithm should be followed.

Questions and possible issues:

• Does use of 'itemref' mean requiring HTML5?
  • No, itemref is not part of the HTML5 specification, it is currently only part of the microdata last call working draft. Thus we would be adding a "new" attribute to HTML above and beyond HTML5, though one that is already specified, and validated by current HTML validators.
• Is 'itemref' documented as a stable draft?
  • 'itemref' is defined in the Last Call Working Draft of microdata. Being "last call" it has some amount of stability, but could still change before it goes to candidate recommendation (CR).
• Doesn't microformats try to avoid introducing new attributes? (e.g. from RDFa in the past).
  • Yes, in general microformats try to avoid introducing new attributes. It may be ok for the set of use-cases that need "itemref". That is, they *are* a minority of actual use-cases, and thus making them use a new attribute is probably ok.
• Wouldn't it be dangerous to adopt features of separate technologies that are unstable, may change, or may disappear?
  • Indeed any time we consider adopting anything from technologies in working drafts we should consider their stability and dependability on a case-by-case basis. When we do decide to re-use such technologies, we should be sure to copy their definition/functionality and provide a non-normative reference to the source, rather than normatively depend on anything that could change or disappear. In the case of 'itemref', it's been stable for a while, and if we believe the schema.org implementation announcements, there are multiple real-world implementations that surface it in common (search) user interfaces.
• Wasn't RDFa a stable augmentation of HTML, and yet we resisted incorporated attributes from it?
  • In practice, no, RDFa has continued to change evolve (which is good) in response to market feedback about its complexity. There was very little real world use (and thus exercising) of RDFa until Google provided it as a Rich Snippets alternative syntax in 2009. At this point, it may be reasonable to also consider attributes from RDFa (e.g. 'vocab' instead of 'profile'), however for this particular purpose (providing inclusion functionality), the 'itemref' attribute/feature makes the most sense.

rejected ideas

n prefix for multiple numbers

Idea:

• "n-*" for (one or more) numbers, e.g. "n-rating", "n-geo", leaving the semantics of more than one number up to specific format. e.g. for an "n-rating" inside an "h-review", the first number would presumably be the rating value, when only two numbers the second would be the "best" value (e.g. rated <span class="n-rating">3 out of 4</span>), when three numbers the second would be the "worst" and the third would be the "best" (e.g. <span class="n-rating">7.5 out of 1 to 10</span>). similarly "n-geo" would specify the first number to be the latitude and the second to be the longitude.

Rejected because while this *might* work for some properties in *English* it will NOT localize/internationalize well (orders of numbers in phrases change in different languages), and it will also limit the human expressivity of the plain text. Thanks to Ben Ward for this feedback at the 2011-06-02 microformats dinner. Tantek 14:25, 9 June 2011 (UTC)

see also

• microformats-2
• microformats-2-brainstorming
• microformats-2-prefixes
• microformats-2-implied-properties
• microformats-2-faq