19 C.F.R. § 201.15

(a) In general. No register of attorneys who may practice before the Commission is maintained. No separate application for admission to practice before the Commission is required. Attorneys practicing before the Commission, or desiring to so practice, must maintain a bar membership in good standing in any State of the United States or the District of Columbia. Persons practicing before the Commission must report any discipline or suspension by any bar association, court, or agency. Non-attorneys desiring to appear before the Commission may be required to show to the satisfaction of the Commission that they are acceptable in the capacity in which they seek to appear. Any person practicing or appearing before the Commission, or desiring to do so, may for good cause shown be suspended or barred from practicing or appearing before the Commission, or may be subject to such lesser sanctions as the Commission deems appropriate, but only after having been afforded an opportunity to present that person's views in the matter.

(b) Former officers or employees. No former officer or employee of the Commission who personally and substantially participated in a matter which was pending in any manner or form in the Commission during that person's employment shall be eligible to practice or appear before the Commission in connection with such matter. No former officer or employee of the Commission shall be eligible to practice or appear before the Commission in connection with any matter which was pending in any manner or form in the Commission during that person's employment without first obtaining written consent from the Commission.