MBA
FYI, I was referring to "Radar Heading" when used by ATC, as in "Speedbird XXX, turn right onto radar heading 230." It is not in CAP413, but it seems to do only good to me.
I agree that the use of "information" or "instructions", as you suggest, does add to the clarity, but I wouldn't get very hung up over a pilot at NW missing it out.
On the other hand, some of the other practices on this thread, such as acknowledging a landing clearance with two clicks of the PTT do seem rather worrying.