Section 121
Executing The Penalty Of Imprisonment
(1) An officer having authority to approve the penalty imposed on a person convicted by a Court
Martial shall issue an order to send him/her in prison to serve the term of
imprisonment or an officer of Court Martial shall issue such order in relation to a person who is convicted by a Summary Court Martial.
(2) Upon receiving an order pursuant to Sub-section (1), the commanding officer of the person subjected to penalty or any other prescribed authority shall send him/her to prison along with a detention letter.
(3) When transferring a prisoner from one place to another, arrangements shall be made to prohibit escape, flee or commission of other  undesirable acts.
(4) If a new order is issued in relation to a prisoner replacing the previous order, the officer who so orders shall issue a detention letter accordingly to the concerned prison chief.
(5) Detention shall not be deemed illegal merely on the ground that there is an error in the detention letter or any document thereto or it does not match with the prescribed format or for any other reason in case a
person has been held in prison as per the decision imposing imprisonment by the Court Martial.
(6) If an order is issued to hold the convicted person in prison to serve the imprisonment, such a convict may be held in custody at any appropriate place until he/she is sent to the prison.
(7) In case the penalty does not exceed the term of Three months, the officer as referred to Sub-section (1) may issue an order to hold such person in military custody until the completion of term of imprisonment.
(8) During a period of military operation, the term of imprisonment may be served by holding him/her in custody as prescribed by the commanding officer. (9) No prisoner held in prison pursuant to this Act shall be subjected
to any corporal punishment during the period of imprisonment; and no penalty of imprisonment shall be imposed on him/her which is not in accordance with the prevailing law.
(10) If the commanding officer of the Army, Corps (Chamu), Division (Pritana) or Brigade (Bahini) believes that it is not possible to execute any penalty in military prison or military custody, he/she may issue an order to hold the concerned person in any prison.