(a) A covered attorney who has formerly represented a client in a matter shall not thereafter represent another person in the same or a substantially related matter in which that person's interests are materially adverse to the interests of the former client, unless the former client gives informed consent, confirmed in writing.
(b) A covered attorney who 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 or to the covered attorney's own advantage, except as Subpart B of this part 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 subpart B of this part would permit or require with respect to a client.
(c) [Reserved]