5 USC 3301 - Civil service; generally

The President may
(1) prescribe such regulations for the admission of individuals into the civil service in the executive branch as will best promote the efficiency of that service;
(2) ascertain the fitness of applicants as to age, health, character, knowledge, and ability for the employment sought; and
(3) appoint and prescribe the duties of individuals to make inquiries for the purpose of this section.