27 CFR §30.72
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Any proprietor using the optional method for determination of proof for spirits containing solids of 400 milligrams or less per 100 milligrams as provided in § 30.71 shall record the obscuration so determined on the record of gauge required by 27 CFR part 19.