You could target a location (fortification, elementary school crossing, etc.) but if you wanted to hit something not fixed on a map, then you'd need a smart round or some sort of guidance once you reached line of sight.
So if you want to blow up a bridge, no problem.
If you want to hit the tank that crossed the bridge 3 minutes ago, then you're guessing where it would be and aiming for a set of coordinates with the hope that your guess is accurate.