Parking sign is devided into two types: read and green. Red means there is a prohibition, limitation or No Parking while Green indicates Parking is allowed. Signs have arrows on a flat surface and only direct parking for the side of the street that the sign and sign pole are located. Parking sign is usually put on a sidewalk or pedestrian crosswalk. On an intersection. In a construction zone, and so on. It is used to let people no where parking is illegal. I think parking sign should be more clear so that people can thoroughly understand its meaning.