Miss. Code § 37-103-21
A military person on active duty stationed in Mississippi who wishes to avail himself or his dependents of the provisions of Section 37-103-17, must submit a certificate from his military organization showing the name of the military member; the name of the dependent, if for a dependent; the name of the organization of assignment and its address (may be in the letterhead); that the military member will be on active duty stationed in Mississippi on the date of registration at the state-supported institution of higher learning or junior college of the State of Mississippi; that the military member is not on transfer orders; and the signature of the commanding officer, the adjutant, or the personnel officer of the unit of assignment with signer's rank and title. A military certificate must be presented to the registrar of the state-supported institution of higher learning or junior college of the State of Mississippi each semester or tri-semester at (or within ten days prior to) registration each semester for the provisions of said section to be effective.
Miss. Code § 37-103-21