Rule 1.9 Duties To Former Clients
(c) A lawyer who has formerly represented a client in a matter or whose present or former firm has formerly represented a client in a matter shall not thereafter:
(1) use information relating to the representation to the disadvantage of the former client except as these Rules would permit or require with respect to a client, or when the information has become generally known; or
(2) reveal information relating to the representation except as these Rules would permit or require with respect to a client.