32 CFR §776.28

1. (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.
2. (b)A covered attorney who has formerly represented a client in a matter shall not thereafter:
   1. (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. (2)Reveal information relating to the representation except as subpart B of this part would permit or require with respect to a client.
3. (c)[Reserved]