Heading Hold

In heading hold, the sticks of the transmitter control the angular velocity of the multicopter: E.g. sticks tilted 20° results in a multicopter that is rotates at 20° per second. Sticks in the neutral position will stop any rotation of the multicopter, but will not bring it back to level flight automatically. This flight mode is very similar to standard rc helicopters, and very is useful for aerobatics.
This movie demonstrates heading hold vs. accelerometer flight mode: HH vs ACC