Subchapter iii. Senate 2 U.S. Code §4721. Referral of ethics violations by Senate Ethics Committee to Government Accountability Office for investigation 2 U.S. Code §4722. Mandatory Senate ethics training for Members and staff 2 U.S. Code §4723. Annual report by Select Committee on Ethics 2 U.S. Code §4724. Amendment to Senate conflict of interest rule 2 U.S. Code §4725. Gifts and travel 2 U.S. Code §4726. Guidelines relating to restrictions on registered lobbyist participation in travel and disclosure 2 U.S. Code §4727. Senate privately paid travel public website 2 U.S. Code §4728. Notification of post-employment restrictions for Senators and employees