29 CFR §1208.7

1. (a)In legal proceedings between private litigants, a subpoena or other demand for the production of records held by the Agency or for oral or written testimony of a current or former NMB employee should be addressed to the General Counsel, National Mediation Board, 1301 K Street NW., Suite 250E, Washington, DC 20005. No other official or employee of the NMB is authorized to accept service of a demand or subpoena on behalf of the Agency.
2. (b)No current or former employee may produce official records or information or provide testimony in response to a demand or subpoena unless authorized by the General Counsel.
3. (c)The General Counsel may grant an employee permission to testify or produce official records or information in response to a demand or subpoena. In making this determination, the General Counsel shall consider whether:
   1. (1)Release of the requested records or testimony is prohibited under § 1208.5;
   2. (2)The disclosure is appropriate under the rules of procedure governing the case or matter;
   3. (3)The requested testimony or records are privileged under the relevant substantive law concerning privilege;
   4. (4)Disclosure would violate a statute or regulation;
   5. (5)Disclosure would reveal trade secrets without the owner's consent; and
   6. (6)Allowing testimony or production of records would be in the best interest of the NMB or the United States.