5.  The general superintendent, with the approval of the Postmaster-General, shall prescribe regulations under which each probationer shall be observed and tested and a record kept of his conduct and capacity, and such record shall determine his fitness for the service and whether he shall be dropped during or at the end of probation or be absolutely appointed.

6.  There may be certified and appointed in each State and Territory, in the manner provided for in this rule, such number of substitute clerks, not exceeding the ratio of one substitute to twenty regular clerks, in such State or Territory as the Post-master-General may authorize, and any vacancies occurring in class 1 in any State or Territory in which substitutes have been appointed shall be filled by the appointment thereto of those substitutes in the order of their appointment as substitutes without further certification.  The time during which any substitute is actually employed in the service shall be counted as a part of his probation.

RAILWAY MAIL RULE V.

1.  Transfers may be made as follows: 

(a) From the classified railway mail service to any classified post-office, and from any classified post-office to the classified railway mail service, upon requisition of the Postmaster-General.

(b) From the classified railway mail service to the Post-Office Department, and from the Post-Office Department to the classified railway mail service, upon requisition of the Postmaster-General.

2.  No person shall be transferred as herein authorized until the Commission shall have certified to the Postmaster-General that the person whom it is proposed to transfer has passed an examination to test fitness for the place to which he is to be transferred, and that such person has been at least six months next preceding the date of the certificate in the classified railway mail service or in the classified service of the post-office or Department from which the transfer is to be made:  Provided, That no employee shall be transferred to any grade which he could not enter by original appointment by reason of any age limitation prescribed by the civil-service rules.

RAILWAY MAIL RULE VI.

1.  Upon requisition of the Postmaster-General the Commission shall certify for reinstatement in a grade or class no higher than that in which he was formerly employed any person who within one year next preceding the date of the requisition has, through no delinquency or misconduct, been separated from the classified railway mail service.

RAILWAY MAIL RULE VII.

1.  The general superintendent of the railway mail service shall report to the Commission—­

(a) Every probational (whether substitute or regular) and every absolute appointment in the railway mail service in each State or Territory; every appointment under any exception to examination authorized by Railway Mail Rule II, clause 5; every reappointment under Railway Mail Rule VI, and every appointment of a substitute to a regular place.