Yeah... but it's not refreshing like fog where distance from camera is always the same. Run the level.... if you set clip_far f.e. 2000 and you (player and camera) will be at 1800 you will not see models at 2100... just 300 away from you. And when you reach 2000 you will disappear.
Clip_far should be like a fog... always at the same distance from camera, am i right? But isn't.
Another words...
Fog it's always distance from camera.
Clip - from nullvector.