Personal experience:
I've had the Citi-business card since Feb and was wondering why it wasn't showing up on my CR. When I called them they told me it's on a "business side of you credit report ," I responded "I didn't know people could have more than one credit report, are you talking about something like Dunn & Bradstreet?" He said 'yes' with some lack of confidence in his voice. So this was the first time I've heard of this.