Final answer:
A licensee who knows a seller is under an exclusive listing with another brokerage should not contact the seller, as this could violate professional ethics and interfere with the existing brokerage agreement.
Step-by-step explanation:
If a licensee knows that a seller is under an exclusive listing with another brokerage, the licensee may not contact that seller. This is because the seller has an agreement with another brokerage, and the attempted contact could be seen as an interference with that contractual relationship. In real estate, the principle of maintaining professional ethics is critical. Licensees are required to respect the exclusive brokerage agreements that sellers have with other professionals. Additionally, real estate markets operate on the premise that buyers and sellers must be well informed of the conditions in the markets and they act independently and compete with each other in a fair manner. Thus, soliciting clients who are already under exclusive contracts does not align with these principles and can be unethical or even illegal in some jurisdictions.