皮匠等大師和其他專家，請指教這到底是什麽意思？

Yesterday called NSC again, the receiver told me that my case is in the hand of fianl reviewer and waiting for visa number. What does that mean?
Has my case been reviewed? Do we have 1st reviewer, 2nd reviewer and final reviewer for the case? But I don't have any LUD or RFE till now. NC has been cleared for a quite while. Thank you!