ent of any determination under this part.

§ 158.5 Testimony of Office employees in proceedings involving the United States.

(a) An Office employee may not testify as an expert or opinion witness for any party other than the United States.

(b) When appropriate, the Solicitor may authorize an Office employee to give testimony as an expert or opinion witness on behalf of the United States. Expert or opinion testimony on behalf of the United States will not be authorized in any legal proceeding involving the validity or enforceability of a patent or registered trademark.

(c) Whenever, in any legal proceeding involving the United States, a request is made by an attorney representing or acting under the authority of the United States, the Solicitor will make all necessary arrangements for the Office employee to give testimony on behalf of the United States. Where appropriate, the Solicitor may require reimbursement to the Office of the expenses associated with an Office employee giving testimony on behalf of the United States.

§ 15a.6 Legal proceedings between private litigants.

(a) Testimony by an Office employee and production of documents in a legal proceeding not involving the United States shall be governed by § 15a.4.

(b) If an Office employee is authorized to give testimony in a legal proceeding, the testimony, if otherwise proper, shall be limited to facts within the personal knowledge of the Office employee. An Office employee is prohibited from giving expert or opinion testimony, answering hypothetical or speculative questions, or giving testimony with respect to subject matter which is privileged. If an Office employee is authorized to testify in connection with the employee's involvement or assistance in a quasi-judicial proceeding which took place before the Office, that employee is further prohibited from giving testimony in response to questions which seek:

(1) Information about that employee's:

(i) Background. (ii) Expertise.

(iii) Qualifications to examine or otherwise consider a particular patent or trademark application.

(iv) Usual practice or whether the employee followed a procedure set out in any Office manual of practice in a particular case.

(v) Consultation with another Office employee.

(vi) Understanding of:

(A) A patented invention, an invention sought to be patented, or patent application, patent, reexamination or interference file.

(B) Prior art.

(C) Registered subject matter, subject matter sought to be registered, or a trademark application, registration, opposition, cancellation, interference or concurrent use file.

(D) Any Office manual of practice. (E) Office regulations.

(F) Patent, trademark, or other law. (G) The responsibilities of another Office employee.

(vii) Reliance on particular facts or arguments.

(2) To inquire into the manner in and extent to which the employee considered or studied material in performing the quasi-judicial function.

(3) To inquire into the bases, reasons, mental processes, analyses, or conculsions of that Office employee in performing the quasi-judicial function.

§ 15a.7 Procedures when an Office employee receives a subpoena.

(a) Any Office employee who receives a subpoena shall immediately forward the subpoena to the Office of the Solicitor. The Solicitor will determine the extent to which an Office employee will comply with the subpoe

na.

(b) If the Office employee is not authorized to comply with the subpoena, the Office employee shall appear at the time and>place stated in the subpoena, produce a copy of Part 15a of Title 15 and a copy of this part, and respectfully refuse to provide any testimony or produce any document.

United States ex rel. Touhy v. Ragen, 340 U.S. 462 (1951).

(c) When necessary or appropriate, the Solicitor will request assistance from the Department of Justice or a

U.S. Attorney or otherwise assure the presence of an attorney to represent the interests of the Office or an Office employee.