37 CFR §42.65
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
- (a)Expert testimony that does not disclose the underlying facts or data on which the opinion is based is entitled to little or no weight. Testimony on United States patent law or patent examination practice will not be admitted.
- (b)If a party relies on a technical test or data from such a test, the party must provide an affidavit explaining: