Plaques bearing, along with the number of the arrondissement, an indication of the name of all roads and squares open to traffic are affixed to buildings, whether built-up or not, located at the corner of two roads open to traffic or opposite the junction of one road with another and at all points of squares and crossroads designated by the Mayor of Paris.
A plaque bearing a serial number is affixed to all buildings, whether built or not, located on the edge of either a thoroughfare or a square open to traffic, even when they do not have an exit from the said thoroughfare or square.