The following items must always be read back:
- ATC route clearances;
- clearances and instructions to enter, land on, take off from, hold short of, cross or backtrack on any runway; and
- runway-in-use, altimeter settings, SSR codes, level instructions, heading and speed instructions, and, whether issued by the controller or contained in Automatic Terminal Information Service (ATIS) broadcasts, transition levels.
In the definition it goes on like this: Other clearances or instructions, including conditional clearances, must be read back. What do I have to obtain from these "other clearances or instructions" I think it is the really broad term?