IMO, and that of Jim Hogshire in the book, "Pills-a-Go-Go" (read it everyone, it's great), the V-cut in brand name Valium is a mindgame Roche plays. A patient who relies on Valium to regulate their mood gets a psychological dependence to that V-shape- they look like the look, the feel, the novelty aspect. When they see the generic is missing that, they question its purity- they like the ability to have their V-cut Valium around at all times because they already know that works. Take it for what you will, but an incredible amount of time, money, and energy goes into pill design and naming.

-yawkaw