37 CFR 1.144 : Patents, Trademarks, And Copyrights (§ 1.1 To Chapter V) — (§ 1.1 To Chapter V) — United States Patent And Trademark Office, Department Of Commerce (§ 1.1 To Parts 151-199) — General (§ 1.1 To §§ 5.31-5.33) — Rules Of Practice In Patent Cases (§ 1.1 To § 1.1071) — National Processing Provisions (§ 1.31 To § 1.378) — Joinder Of Inventions In One Application; Restriction (§ 1.141 To § 1.146) — Petition from requirement for restriction.