Recommendations for commissions will be made by the authorized head of the institution to the adjutant general. Commissions shall be for the term of two years, unless terminated by removal for cause, resignation, or ceasing to be an attendant at the school. Commissions will be upon a specific blank prepared for this purpose, and will be signed by the governor and secretary of state, and attested by the adjutant general. All commissioned officers will be required to subscribe to the regular oath of office.