First you have to know all the things it's used for, and possibly even Microsoft doesn't know. Short of that, you have to duplicate all of its functionality. Yo

First you have to know all the things it's used for, and possibly even Microsoft doesn't know. Short of that, you have to duplicate all of its functionality. You can't follow the 80-20 rule if you don't even know the 20. I think this is also one of the causes behind the Second System Effect.