CFR›Title 43›Subtitle B›Chapter II›Part 3140›Subpart 3140›Subject Group Applications›43 CFR 3140.21 Citation43 CFR 3140.21CorpusDaily eCFRDisplayed edition2026-05-12Last updated2026-05-12 § 3140.21 Forms.No special form is required for a conversion application. Next 3140.22 § 3140.22 Who may apply.