37 CFR 42.61: Admissibility.

(a) Evidence that is not taken, sought, or filed in accordance with this subpart is not admissible.

(b) Records of the Office. Certification is not necessary as a condition to admissibility when the evidence to be submitted is a record of the Office to which all parties have access.

(c) Specification and drawings. A specification or drawing of a United States patent application or patent is admissible as evidence only to prove what the specification or drawing describes. If there is data in the specification or a drawing upon which a party intends to rely to prove the truth of the data, an affidavit by an individual having first-hand knowledge of how the data was generated must be filed.