There are excepted from examination the following: (1) The confidential
clerk or secretary of any head of a Department or office; (2) cashiers
of collectors; (3) cashiers of postmasters; (4) superintendents of
money-order divisions in post-offices; (5) the direct custodians of
money for whose fidelity another officer is under official bond, and
disbursing officers having the custody of money who give bond; but these
exceptions shall not extend to any official below the grade of assistant
cashier or teller; (6) persons employed exclusively in the secret
service of the Government, or as translators, or interpreters, or
stenographers; (7) persons whose employment is exclusively professional,
but medical examiners are not included among such persons; (8) chief
clerks, deputy collectors, deputy naval officers, deputy surveyors of
customs, and superintendents or chiefs of divisions or bureaus. But no
person so excepted shall be either transferred, appointed, or promoted,
unless to some excepted place, without an examination under the
Commission, which examination shall not take place within six months
after entering the service. Promotions may be made without examination
in offices where examinations are not now held until rules on the
subject shall be promulgated.