Google changed robots.txt and included entries for finance, externa_js and MBD.

Old robots: http://72.14.203.104/search?q=cache:4V5KG6DE54gJ:www.google.com/robots.txt+&hl=en&ct=clnk&cd=1

New robots:
http://www.google.com/robots.txt

It's weird to see that http://www.google.com/mbd resolves correctly, it serves a blank page. What could mean MBD?

million barrels per day
minimal brain dysfunction
* ?