This is a cut and pasted from what already posted:

We've had this discussion before. Say the rev limiter is 7,500 RPMs and you are rapidly approaching this. When your car (the ECU, that is) hits 7,500 rpms an electronic/digital signal is sent to cut fuel delivery, which is an mechanical function. But during the miniscule amount of time it takes for the ECU to register an over-rev and send the signal to cut off fuel, and then for the fuel to actually be cut off, the engine is still increasing RPMs. Thus you have a small Range 1 or 2 over-rev. I wonder for those that run right on the RPM rev limit rivet if they don't actually exceed the limit for a fraction of a second, but by slightly backing off quickly enough to just below the limit no cut-off message is sent. The only way to really know this though is to actually see the ECU coding. But think about it for a second. Why else would Porsche say that Range 1 and 2s are acceptable. I think they understand that this slight time lag exists and the resulting "over-rev" is inconsequential. But take that a step further. If the red line on your engine is 7,500 RPMs, and Porsche knows that the cut-off time lag would rev the engine to a bit above this for a very short time, then is the red line really 7,500 RPMs? I mean Porsche could program the ECU to cut out at 7,300 RPMs so you would never go above 7,500 RPMs (downshifts notwithstanding). So, Porsche knows that your engine is good to a bit above the red line for that short period of time.

In the end, Range 1 or 2 over-revs aren't much of a concern, unless you get a DME that shows thousands or tens of thousands of them - and all this would mean is that the car was driven at its limit a fair amount.