national frequencies

I have been programming the scanner using both Sentinel and ARC 536 PRO software. It doesn't seem very easy but I have been for the most part successful if I am programming local/county/state frequencies .have been trying to enter the National Maritime VHF and Nationwide Railroad frequencies...

I want to download the National Interoperability frequencies. I can locate some of them within RR, but can't figure out where they "live" from within the Web Import option through Win500. They are not shown as being part of any State nor County I've looked in. Any Ideas RR folks?