Is "self grounding" a well defined feature? Will my inspector automatically accept what it means? I am installing outlets & switches in a garage with steel boxes, leaving off the pig tails would be nice. But I cannot find a clear definitive document that states a "self grounding" fixture does not need the pigtail. The install instructions do not mention it. I even called Leviton tech support, he referred to several documents that I already saw, they all mention "self grounding" in a vague general way but none come right out and definitively say that no pigtail is needed. Just worried the inspector may want to see proof. Thanks.