37 CFR § 11.50 - Evidence.
(a) Rules of evidence. The rules of evidence prevailing in courts of law and equity are not controlling in hearings in disciplinary proceedings. However, the hearing officer shall exclude evidence that is irrelevant, immaterial, speculative, or unduly repetitious.
(b) Depositions. Depositions of witnesses taken pursuant to § 11.51 may be admitted as evidence.
(c) Government documents. Official documents, records, and papers of the Office, including, but not limited to, all papers in the file of a disciplinary investigation, are admissible without extrinsic evidence of authenticity. These documents, records, and papers may be evidenced by a copy certified as correct by an employee of the Office.
(d) Exhibits. If any document, record, or other paper is introduced in evidence as an exhibit, the hearing officer may authorize the withdrawal of the exhibit subject to any conditions the hearing officer deems appropriate.
(e) Objections. Objections to evidence will be in short form, stating the grounds of objection. Objections and rulings on objections will be a part of the record. No exception to the ruling is necessary to preserve the rights of the parties.