JR calls it Mode 3 and, as I understand, Futaba originally called it "Stick 4," but may use mode 4 by now.

As has been mentioned, it is the left-handed version of mode 2, which has alieron and elevator on the same stick. As a left hander, I have been flying this mode for years, since 1975. I started earlier with a left-handed single stick radio.

Mode 1 and the opposite version, mode 4, has the aileron and elevator on different sticks.