An arrangement by which real estate brokers place their listings together so that all members of the multiple-listing service have an opportunity to sell properties listed by other members of the service.A real estate agent is a REALTOR® when he or she becomes a member of the NATIONAL ASSOCIATION of REALTORS® The term REALTOR® is a registered collective membership mark that identifies a real estate professional who is a member of the NATIONAL ASSOCIATION of REALTORS® and subscribes to its strict Code of Ethics.Hold mouse over logo for description.