Home › CFR › Title 41 › Part 51-541 CFR Part 51-5 — Contracting Requirements§ 51-5.1— General.§ 51-5.2— Authorization/deauthorization as a mandatory source.§ 51-5.3— Scope of requirement.§ 51-5.4— Purchase exceptions.§ 51-5.5— Prices.§ 51-5.6— Shipping.§ 51-5.7— Payments.§ 51-5.8— Violations by entities of the Government.