Shaved can mean 2 things.
A. could be blue printed and balanced where they spin it and then shave off any places where there is a little extra weight that throws the crank of ballance. With the balanced crank, engine vibration is reduced and there is less where on everything, expensive, mainly a diehard racing kind of thing. (honda does a good job in the first place of keeping their parts balanced from the factory but nothing is perfect when your mass producing crap)
B. It is kifed edged. This is where they shafe off peices of the counter weights to remove exess weight. Pretty cool shit but it is easy to over rev because this causes much better throttle responce (revs up real quick)