What condition must be met for a sign to be placed at a property by a real estate broker?

For a sign to be placed at a property by a real estate broker, it is essential that the seller provides written consent. This condition is crucial because it formalizes the relationship between the broker and the seller and ensures that the broker has the right to market the property publicly. A written agreement also protects the interests of both parties by clearly laying out the terms, responsibilities, and permissions involved in the selling process.

Having written consent also helps avoid potential disputes regarding the broker's authority to advertise the property. Without it, the broker may not be legally authorized to enter the property or engage in promoting it, which could lead to misunderstandings or legal repercussions. Hence, securing the seller's agreement in writing is a fundamental requirement in real estate transactions and advertising practices.

In contrast, other options such as having an oral agreement, listing on the MLS, or the property being vacant do not fulfill the legal necessity required for placing a sign on the property.