Microdata and RDFa Living Together in Harmony from Jeni’s Musings is valuable reading for anyone interested in the semantic web. It’s a long article full of fine-grained suggestions. She concludes,
Regardless, there are lessons that RDFa and microdata could learn from each other, and changes to both languages that would help developers use them on their own, switch between them and mix them in the same document. I expect and welcome debate about the viability and effectiveness of the changes and guidelines that I’ve suggested here.
Public discussion of Jeni’s post is on Google+ as well as her blog.
A matter of protocol talks about protocol relative URIs. From Adactio.
Who’s Validating the Validators talks about the damage that invalid embed code picked up from 3rd party sites as content does to the Internet.