5.  In case of the occurrence of a vacancy in the classified service of any internal-revenue collection district which the public interest requires shall be immediately filled, and there is no eligible entitled to reinstatement under section 1, clause (b), of this rule or remaining on the proper register, such vacancy, if in the class of storekeeper, storekeeper and gauger, or clerk, may be filled without examination and certification by a temporary designation by the collector of the district of some suitable person to perform the duties of the position until a regular appointment can be made under the provisions of sections 1, 2, and 3 of this rule:  Provided, That service under such temporary designation shall in no case continue longer than six months, and shall expire by limitation at the end of that time:  And provided further, That no person shall serve more than six months in any one year under such temporary designation, the year limitation in regard to such designation to begin to run on the date thereof.

  Every such temporary designation and also the discontinuance of the same
  shall at once be reported to the Commission.

  INTERNAL-REVENUE RULE V.

Until promotion regulations shall have been applied to a classified internal-revenue collection district promotions therein may be made upon any test of fitness determined upon by the Commissioner of Internal Revenue, with the approval of the Commission:  Provided, That no employee shall be promoted to any grade he could not enter by appointment under the minimum age limitation applied thereto by section 2 of Internal-Revenue Rule II.

  INTERNAL-REVENUE RULE VI.

  Transfers may be made as follows: 

From one classified internal-revenue collection district to another, from any classified internal-revenue collection district to a bureau in the Treasury Department in which business relating to the internal revenue is transacted, and from such a bureau in the Treasury Department to such a district, upon the requisition of the Secretary of the Treasury and the certification of the Commission, the appointment upon such transfer to be made by the Secretary of the Treasury, upon the recommendation of the Commissioner of Internal Revenue, if the place to be filled by such transfer is that of storekeeper, storekeeper and gauger, or gauger:  Provided, That no person shall be transferred as herein authorized who is not within the age limitations prescribed by the civil-service rules for the place to which he is to be transferred and who has not been absolutely appointed, or, if appointed without civil-service examination, who has not served six months continuously in the district or bureau from which he is to be transferred.

  INTERNAL-REVENUE RULE VII.