You've got us confused, MrMister!
There's no such thing as THE Business Directory. There are just countless publications and websites which are referred to as business directories. Most of them do little more (if anything) than simply list businesses and their contact numbers. (Yellow Pages is a general business directory but there are lots of specialists ones, e.g. there's a business directory, used by advertising companies, which provides contact details and advertising rates for every newspaper and magazine in the country).
So it's impossible to directly answer your question.
However, if you're looking to start a business, this is where you should start:
http://www.businessli...er?topicId=1073858805
(You'll see that, among many other things, there's a tab labelled 'Directories').
Chris