However, thinking about it, we are surrounded by signs which inform or instruct us. Everybody who does laundry will know this one!
Then I thought really hard and came up with the idea of MAPS! After all, maps in themselves are signs. And if up to date, then of the time!
This might not be exactly what Carmi meant, but its the result of lateral thinking! To see signs from other photographers, go to the link above.