You normally have two settings on most fighter-type aircraft, bright-flash, or dim-steady. It's mostly for a visibility issue, and it differs by airframe. On the F-16, you'll see them in bright-flash inflight, along with the white strobe on top of the vert stab. On A-10s, there's strobes on each wingtip and the tail stinger, so common practice is to fly with dim-steady and have bright-flash on when on the ground and the strobes are off.