Final answer:
Brokers must obtain written consent from the property owner before placing a 'For Sale' sign on a property.
Step-by-step explanation:
In order for a broker to place a 'For Sale' sign on a property, they must first obtain the written consent of the property owner. This ensures that the owner gives permission for the sign to be placed on their property. It is important for the broker to have this written consent to avoid any legal issues.