1. The classified customs service shall include the officers, clerks, and other persons in the several customs districts classified under the provisions of section 6 of the act to regulate and improve the civil service of the United States, approved January 16, 1883.
2. Whenever the officers, clerks, and other persons in any customs district number as many as fifty, any existing classification of the customs service made by the Secretary of the Treasury under section 6 of the act of January 16, 1883, shall apply thereto, and thereafter the Commission shall provide examinations to test the fitness of persons to fill vacancies in said customs district and these rules shall be in force therein. Every revision of the classification of any customs office under section 6 of the act above mentioned, and every inclusion within the classified customs service of a customs district, shall be reported to the President.
CUSTOMS RULE II.
1. To test fitness for admission to the classified customs service, examinations shall be provided as follows:
Clerk examination[18]—This examination shall not include more than the following subjects:
(a) Orthography.
(b) Copying.
(c) Penmanship.
(d) Arithmetic—fundamental rules, fractions, percentage, interest, and discount.
(e) Elements of bookkeeping and of accounts.