I don’t understand this measure as well. Half of Caucasus mountains are in Russia, and I’m sure most USAmericans won’t like to be identified as Russians.
curiously, in Russia, Caucasians is the collective term for the nations of the Caucasus, and it is often used to express Chauvinist opinions about them. Russians are usually confused when they are referred to as "Caucasian" in american paperwork
People have downvoted me for saying the same thing. Perhaps they were offended by the term "US Americans"? It is a standard term used here in Germany and is not offensive.