eCFR

Electronic Code of Federal Regulations (eCFR): authoritative current text of all 50 CFR titles. Use for any question about federal regulations — securities (17 CFR), drugs and food (21 CFR), environment (40 CFR), labor (29 CFR), tax (26 CFR), etc. Pass an explicit citation ('21 CFR 201.25', '16 CFR 1700.14', '17 CFR 240.10b-5') to get that section's authoritative current text plus any pending amendment; pass a short topic phrase (3-6 specific terms, not a full sentence) to search by relevance. Never state a CFR section number you have not retrieved here.