2 U.S. Code § 506 2 U.S. Code § 506 is about Mass mailing sent by House Members. It is under Chapter 16 (Congressional Mailing Standards) of Title 2

2 U.S. Code § 505 2 U.S. Code § 505 is about Mass mailing of information by Senators under frank; quarterly registration with Secretary of Senate. It is under

2 U.S. Code § 504 2 U.S. Code § 504 is about Mass mailings by Senate offices; quarterly statements; publication of summary tabulations. It is under Chapter 16 (Congressional

2 U.S. Code § 503 2 U.S. Code § 503 is about Official mail of persons entitled to use congressional frank. It is under Chapter 16 (Congressional Mailing Standards)