Just a moniker, I assume the BBL might stand for Batali, Bastianich, Lidia?. As i recall, the menu says something about it being generally better than prime(USDA). It is purportedly all natural, hormone-free, etc. I've never actually heard/read what farm/ranch supplies the meat though. If you inquire when you guys go, I'm sure they can provide further info. Enjoy the anniv.