That's them. I had a look at these when it first was 'released' by Google, but back then it was more of an 'opt in' system I believe, with Google having to approve senders who were going to embed these schemas into their emails.

Have to revisit this now to see if they have relaxed the requirements a little. It will be good if these became a normal extension to all emails and other clients such as Outlook, Yahoo Mail etc. all pick it up as a standard.