17 CFR §201.120

1. (a)Except to the extent required for the disposition of ex parte matters as authorized by law, the person presiding over an evidentiary hearing may not:
   1. (1)Consult a person or party on a fact in issue, unless on notice and opportunity for all parties to participate; or
   2. (2)Be responsible to or subject to the supervision or direction of an employee or agent engaged in the performance of investigative or prosecuting functions for the Commission.
2. (b)The Commission's code of behavior regarding ex parte communications between persons outside the Commission and decisional employees, 17 CFR 200.110 through 200.114, governs other prohibited communications during a proceeding conducted under the Rules of Practice.