It shall be unlawful for any officer or employee of the United States or any person described in section 6103(n) [26 USCS ?? 6103(n)] (or an officer or employee of any such person), or any former officer or employee, willfully to disclose to any person, except as authorized in this title, any return or return information (as defined in section 6103(b) [26 USCS ?? 6103(b)]).