We know that bags fall in several categories such as: backpack, messenger bag, duffel bag, briefcase, and so on. I would like to ask about the office bag, or laptop bag, that has zipper goes around 3 sides and opens up like a clam shell, what do you call it ??? I know it might be called a laptop bag, but it seems that many bags of different types are called laptop bags. A messenger bag which has a sleeve for a laptop can be called a laptop bag. See my point ??