Although I do not understand the reasoning for this code rule, I always understood that if you have the old 2 prong outlets, fed from old cable, which does not have a ground wire, that you can NOT run a single green wire from the breaker box ground buss, to the ourlet(s), to ground them. Yet, I saw someone suggest doing this on a blog. Of course blogs are like this newsgroup, and are not always good information.
As I said, I think this rule is sort of senseless, because as long as the added wire was of the same gauge, connected to the ground buss in the panel, it would make safer wiring. Of course replacing the old cable is the preferred method, that is not always possible without ripping a house apart.
Just wondering if anyone has any further information about doing this? Is this ever allowed for any reasons?