Incorrect. Unfortunately everyone thinks they know what it is, but they really don't. Here's the scoop:
This is the way it works. DSC is on when you start the car. That's Dynamic Stability Control. That will limit the engine power, and apply breaks to certain wheels if any wheelspin is detected, or if the car is getting out of control.
When you press the DTC button, you are engaging Dynamic Traction Control. Dynamic traction control is a limited form of DSC. It will allow some wheelspin up to 40mph in order to gain better traction in slick conditions such as heavy snow. It will still save you if you get out of control, but there will need to be a bit more loss of control before it happens.
When you press and hold the DTC button you are shutting off DSC. There is no traction control to help you at all. You're on your own.
The owners manual is available online via PDF and goes over it more thoroughly