16 C.F.R. § 1025.43 – Evidence.

(a) Applicability of Federal Rules of Evidence. Unless otherwise provided by statute or these rules, the Federal Rules of Evidence shall apply to all proceedings held pursuant to these Rules. However, the Federal Rules of Evidence may be relaxed by the Presiding Officer if the ends of justice will be better served by so doing.
(b) Burden of proof.
1. (1) Complaint counsel shall have the burden of sustaining the allegations of any complaint.
2. (2) Any party who is the proponent of a legal or factual proposition shall have the burden of sustaining that proposition.
(c) Admissibility. All relevant and reliable evidence is admissible, but may be excluded by the Presiding Officer if its probative value is substantially outweighed by unfair prejudice or confusion of the issues, or by considerations of undue delay, waste of time, immateriality, or needless presentation of cumulative evidence.
(d) Official notice—(1) Definition. Official notice means use by the Presiding Officer or the Commission of facts not appearing on the record and legal conclusions drawn from those facts. An officially noticed fact or legal conclusion must be one not subject to reasonable dispute in that it is either:
1. (i) Generally known within the jurisdiction of the Commission or
2. (ii) Capable of accurate and ready determination by resort to sources whose accuracy cannot reasonably be questioned.
3. (2) Method of taking official notice. The Presiding Officer and/or the Commission may at any time take official notice upon motion of any party or upon its own initiative. The record shall reflect the facts and conclusions which have been officially noticed.
(e) [Reserved]
(f) Offer of proof. When an objection to proffered testimony or documentary evidence is sustained, the sponsoring party may make a specific offer, either in writing or orally, of what the party expects to prove by the testimony or the document. When an offer of proof is made, any other party may make a specific offer, either in writing or orally, of what the party expects to present to rebut or contradict the offer of proof. Written offers of proof or of rebuttal, adequately marked for identification, shall accompany the record and be available for consideration by any reviewing authority.