CDP is a Cat A term, it is specifically where one must make the critical decision, go or stay. Go occurs after CDP, stay is before or at.
Regarding Xnr's question of how to reject, I suggest the method that harms the aircraft least. If your takeoff area is exactly the Rejected Takeoff distance, so that the large Oak Tree has your name on it if you do not flare agressively and then pull the snot out of the engine, by all means do so. In fact, I assure you that you will, since Oak is tougher than air, and you instinctively know that!
When we set the distance in test to produce the RFM charts, we use still air, max weight and an engine that is set to produce only the 2.5 min power. It does not over temp and over torque, so we have eliminated that nice source of extra power. In the real case, you have that available to you, and it helps make the distance shorter.
By all means don't pull the OEI ratings in routine practice, as you will reduce engine life. I almost always simply practice using two motors, and half the single torque in dual engine mode. This allows lots of escapes, little engine wear, and no danger of an all-thumbs person cutting both of those noisey suckers, thus creating that awesome silence that some only dream about.
The Vtoss for US and UK procedures is somewhat different, as I recall, since the old BCAR climb gradient is steeper than the FAA climb (BCAR was gven as a percent gradient, I believe 100 feet per mile, FAA was a simple 100 feet per minute climb rate), so we had to get closer to Vy to allow the better climb in the UK manual.