8.  No person who has passed an examination shall while eligible on the register supplied by such examination be reexamined, unless he shall furnish evidence satisfactory to the Commission that at the time of his examination he was, because of illness or for other good cause, incapable of doing himself justice in said examination.

  9.  The term of eligibility to appointment in the classified postal
  service shall be one year from the day on which the name of the eligible
  is entered on the register.

  POSTAL RULE IV.

  1.  Vacancies in the classified service of a post-office, unless among
  the places excepted from examination, if not filled by either transfer
  or promotion, shall be rilled in the following manner: 

(a) The postmaster at a post-office in which a vacancy may exist shall, in form and manner to be prescribed by the Commission, request the board of examiners to certify to him the names of either males or females eligible to the vacant place.

(b) If fitness for the place to be filled is tested by competitive examination, the board of examiners shall certify the names of three males or three females, these names to be those of the eligibles who, standing higher in grade than any other three eligibles of the same sex on the register from which certification is to be made, have not been certified three times from said register:  Provided, That if upon said register there are the names of eligibles who, under section 1754 of the Revised Statutes, have claim of preference in civil appointments, the names of such eligibles shall be certified before the names of other eligibles higher in grade.  The Commission shall make regulations that will secure to each of such preference-claiming eligibles, in the order of his grade among other preference claimants, opportunity to have his claim of preference considered and determined by the appointing officer.

  (c) Each name on any register of eligibles may be certified only
  three times.

2.  Of the three names certified to him the postmaster must select one; and if at the time of making this selection there are more vacancies than one, he may select more than one name.  Each person thus designated for appointment shall be notified, and upon reporting in person to the postmaster shall be appointed for a probational period of six months, at the end of which period, if his conduct and capacity be satisfactory to the postmaster, he shall receive absolute appointment; but if his conduct and capacity be not satisfactory to said officer, he shall be notified that he will not receive absolute appointment, and this notification shall discharge him from the service.

3.  The postmaster of each classified post-office shall require the superintendent of each division of his office to carefully observe and report in writing the services rendered by and the character and qualifications of each probationer serving under him.  These reports shall be preserved on file, and the Commission may prescribe the form and manner in which they shall be made.

  POSTAL RULE V.