REALTORS® Code of Ethics: Duties to Clients and Customers, Article 1, Standard of Practice 1-9

The obligation of REALTORS® to preserve confidential information (as
defined by state law) provided by their clients in the course of any
agency relationship or non-agency relationship recognized by law
continues after termination of agency relationships or any non-agency
relationships recognized by law. REALTORS® shall not knowingly, during
or following the termination of professional relationships with their
clients:
1) reveal confidential information of clients; or
2) use confidential information of clients to the disadvantage of
clients; or
3) use confidential information of clients for the REALTOR®ʼs advantage
or the advantage of third parties unless:
a) clients consent after full disclosure; or
b) REALTORS® are required by court order; or
c) it is the intention of a client to commit a crime and the
information is necessary to prevent the crime; or
d) it is necessary to defend a REALTOR® or the REALTOR®ʼs employees or
associates against an accusation of wrongful conduct.
Information concerning latent material defects is not considered confidential
information under this Code of Ethics.

See entire Code of Ethics HERE