Reno, I still believe it is the paper packing in RX that is not water friendly. It might wick water into boxes etc.
That seems to be the concern when you read the "flooded house" articles. Maybe someone has a link to the NOLA article in IAEI News.
As far as I can determine, NM-C is NM with a plastic packing instead of paper. I have never actually seen any NM-C and I do not think Southwire really makes it, hence routing me to UF when I try to look it up (assuming I want to buy a pallet I guess).
