the classified customs
service, except that of clerk or messenger, who is under 21 years of
age; but these limitations of age shall not apply to persons honorably
discharged from the military or naval service of the country who are
otherwise duly qualified.

RULE XVI.

1. Whenever any officer having the power of appointment or employment
shall so request, there shall be certified to him by the Commission or
the proper examining board four names for the vacancy specified, to be
taken from those graded highest on the proper register of those in his
branch of the service and remaining eligible, regard being had for any
right of preference and to the apportionments to States and Territories;
and from the said four a selection shall be made for the vacancy. But
if a person is on both a general and a special register he need not be
certified for the former, except at the discretion of the Commission,
until he has remained two months upon the latter.

2. These certifications for the service at Washington shall be made
in such order as to apportion, as nearly as may be practicable, the
original appointments thereto among the States and Territories and the
District of Columbia upon the basis of population as ascertained at the
last preceding census.

3. In case the request for any such certification or any law or
regulation shall call for those of either sex, persons of that sex shall
be certified; otherwise sex shall be disregarded in such certification.

4. Subject to the other provisions of this rule, persons eligible on
any register shall be entitled to three certifications only to the
same officer, but with his request in writing there may be a fourth
certification of such persons to him when reached in order. No one shall
remain eligible for more than one year upon any register, except as may
be provided by regulation; but these restrictions shall not extend to
examinations under clause 5 of Rule VII. No person while remaining
eligible on any register shall be admitted to a new examination, and no
person having failed upon any examination shall within six months be
admitted to another examination without the consent of the Commission.

5. Any person appointed to or employed in any place in the classified
service who shall be dismissed or separated therefrom without fault or
delinquency on his part may be reappointed or reemployed in the same