law: 141. Presumption as to certain documents.-
  (1) A letter, return or other document respecting the service of any person in, or the cashiering, dismissal or discharge of any person from, any portion of the Air Force, or respecting the circumstance of any person not having served in, or belonged to, any portion of the Forces, if purporting to be signed by or on behalf of the Central Government or 1[the Chief of the Air Staff], or by any prescribed officer, shall be evidence of the facts stated in such letter, return or other document.
  (2) An Army, Navy or Air Force List or Gazette purporting to be published by authority shall be evidence of the status and rank of the officers or warrant officers therein mentioned, and of any appointment held by them and of the unit or branch of the services to which they belong.
  (3) Where a record is made in any service book in pursuance of this Act or of any rules made thereunder or otherwise in pursuance of air force duty and purports to be signed by the commanding officer or by the officer whose duty it is to make such record, such record shall be evidence of the facts therein stated.
  (4) A copy of any record in any service book purporting to be certified to be a true copy by the officer having custody of such book shall be evidence of such record.
  (5) Where any person subject to this Act is being tried on a charge of desertion or of absence without leave, and such person has surrendered himself into the custody of any officer or other person subject to this Act, or any portion of the Air Force, or has been apprehended by such officer or person, a certificate purporting to be signed by such officer, or by the commanding officer of that portion of the Air Force, or by the commanding officer of the unit, or detachment to which such person belongs, as the case may be, and stating the fact, date and place of such surrender or apprehension, and the manner in which he was dressed, shall be evidence of the matters so stated.
  (6) Where any person subject to this Act is being tried on a charge of desertion or of absence without leave, and such person has surrendered himself into the custody of or has been apprehended by, a police officer nor below the rank of an officer-in-charge of a police station, a certificate purporting to be signed by such police officer and stating the fact, date and place if such surrender or apprehension and the manner in which he was dressed shall be evidence of the matters so stated.
  (7) Any document purporting to be a report under the hand of any Chemical Examiner or Assistant Chemical Examiner to Government upon any matter or thing duly submitted to him for examination or analysis and report may be used as evidence in any proceeding under this Act.