GRDDL and RDFa

This is how we create our own microformats under Blue Obelisk… from the GRDDL tutorial

Is it too much work to ask people to add the transformation and profile to their individual instance data?
Creators or maintainers of vocabularies can also give users of their data the option of having their data transformed into RDF without having to even add any new markup to individual documents
Since once the tranformation has been linked to the profile or namespace document, all the users of the dialect get the added value of RDF for free
In either the namespace document or profile URI there has to be the following RDF property: http://www.w3.org/2003/g/data-view#profileTransformation whose subject is the namespace doc or profile document and whose object is the transformation itself.
While GRDDL has primarily in the wild been used to convert widely deployed microformats to RDF, it can actually be used with the W3C RDFa work item that allows one to “microformat-style” embed arbitary RDF statements in HTML
RDFa is useful because microformats exist as a number of centralized vocabularies, and what if you want to mark-up meta-data in a web-page about a subject there isn’t a microformat about?
Since RDFa is still a moving target, we personally recommend people use Embedded RDF for the time being unless they are willing to track the changes in RDFa, but RDFa is more expressive than Embedded RDF (allowing XML Schema datatypes, etc.

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CC License
  and was written by TimBL.

• use existing HTML attributes whenever possible: rel.
• “Bridging the Clickable and Semantic Webs”: there’s already a clickable link, now we type it.
• self-contained:
  • copy-and-paste a chunk of HTML along with its RDFa.
  • build “RDFa wizards” to create copy-and-paste-able content-and-structure.
  • combine “widgets” on a page, each widget with its own HTML+RDFa (no interference).

The point is that we can embed our own namespace and profile. The main downside is we can’t do datatypes. But we could start immediately