The artist Kurt Spurey used an oversized traffic-red checkmark made of aluminum rectangular tubing (ten by three meters) to mark various public locations and buildings. Thus, checked off was mounted on a house facade at Praterstraße 10, while it "cut through" the World Exhibition Office at Praterstraße 42, projecting into the yard through multiple windows. The red checkmark was last seen in 2006 as part of the FISCHERSTIEGE alter ego at Fischerstiege in the 1st district.