That sort of makes sense if you interpret it as circle/line and not 0/1. A circle for an open vent and a line for a closed vent. That's still dumb though. Why

That sort of makes sense if you interpret it as circle/line and not 0/1. A circle for an open vent and a line for a closed vent. That's still dumb though. Why not use the universal bacon/no bacon icons?