October 13, 1905
No officer or employee of the government shall, directly or indirectly, instruct or be concerned in any manner in the instruction of any person, or classes of persons, with a view to their special preparation for the examination of the United States Civil Service Commission. The fact that any officer or employee is found so engaged shall be considered sufficient cause for his removal from the service.
THEODORE ROOSEVELT.
Theodore Roosevelt, Executive Order Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/206639