Originally Posted by tuggyne
That ... actually makes a lot of sense, for many characters.
There's a reason special forces in particular and combat personell in general use such short-hand IRL.
Rapid communication is essential on the battlefield, and things like using the numbers of a clockface as stand-ins for directional warnings is a logical extension of that principal.
"4 o'clock, high" gets said, heard, and processed faster than, "Look out behind you, to your left, and above you." It also avoids confusion since in the first instance you clearly mean one target in a specific direction rather than the possible three targets in three general directions, that the second could mean.