RFNA is a rocket fuel (a storeable oxidiser): red fuming nitric acid. HNO3 + 13% N2O4 and 3% H20. The colour of the resulting red fuming nitric acid is imparted by N204.
... from November 1940. Head of the French section was colonel Maurice Buckmaster[?]. They sent weapons, radios and radiomen and advisors. One of their agents was ...