The act of visual surveillance and clue-finding to avoid the urinal that was just used, thereby avoiding the urine cloud of the previous pisser.
When a dude is washing his hands when I enter the restroom, I employ UCAM (Urine Cloud Avoidance Maneuver) to scan the urinals for the flush trails of the most recently flushed urinal. That's the one to avoid. I see the flush trail, I use the other urinal. If I'm not paying attention, or have no choice because its busy, the nasty odor of some other guy's urine cloud just hangs and it's worse than walking into a spider web.