(3) Post-employment restrictions are covered by 18 U.S.C. 207 and 5 CFR parts 2637 and 2641, that prohibit certain activities by former Government employees, including representation of a contractor before the Government in relation to any contract or other particular matter involving specific parties on which the former employee participated personally and substantially while employed by the Government. Additional restrictions apply to certain senior Government employees and for particular matters under an employee’s official responsibility;