37 CFR § 11.106 - Confidentiality of information.
(a) A practitioner shall not reveal information relating to the representation of a client unless the client gives informed consent, the disclosure is impliedly authorized in order to carry out the representation, the disclosure is permitted by paragraph (b) of this section, or the disclosure is required by paragraph (c) of this section.
(1) To prevent reasonably certain death or substantial bodily harm;
(2) To prevent the client from engaging in inequitable conduct before the Office or from committing a crime or fraud that is reasonably certain to result in substantial injury to the financial interests or property of another and in furtherance of which the client has used or is using the practitioner's services;
(3) To prevent, mitigate, or rectify substantial injury to the financial interests or property of another that is reasonably certain to result or has resulted from the client's commission of a crime, fraud, or inequitable conduct before the Office in furtherance of which the client has used the practitioner's services;
(4) To secure legal advice about the practitioner's compliance with the USPTO Rules of Professional Conduct;
(5) To establish a claim or defense on behalf of the practitioner in a controversy between the practitioner and the client, to establish a defense to a criminal charge or civil claim against the practitioner based upon conduct in which the client was involved, or to respond to allegations in any proceeding concerning the practitioner's representation of the client;
(6) To comply with other law or a court order; or
(7) To detect and resolve conflicts of interest arising from the practitioner's change of employment or from changes in the composition or ownership of a firm, but only if the revealed information would not compromise the practitioner-client privilege or otherwise prejudice the client.
(d) A practitioner shall make reasonable efforts to prevent the inadvertent or unauthorized disclosure of, or unauthorized access to, information relating to the representation of a client.