CFR›Title 7›Subtitle B›Chapter I›Part 51›Subpart B›Subject Group Marking Requirements ContainsSection 51.311CorpusDaily eCFRDisplayed edition2026-06-12Last updated2026-06-12 Sections 51.311 § 51.311 Marking requirements. Previous Grades Grades Next Methods of Sampling and Calculation of Percentages Methods of Sampling and Calculation of Percentages