Commissions of National Guard officers shall be vacated as provided by the laws or regulations of the United States. Any commissioned officer of the National Guard who resigns or is retired and who shall have served as such officer for a period of not less than ten years, and any commissioned officer of the National Guard who has been honorably discharged from the Army of the United States after serving therein for a period of ninety days or more during any war and who shall have served as such officer of the National Guard for a period of not less than five years, and any commissioned officer of the National Guard who has become, or who shall hereafter become, disabled and thereby incapable of performing the duties of his office, may, upon his retirement upon his own request in writing, stating the grounds therefor, and by order of the Governor, have his name placed on a roll in the office of the Adjutant General to be known as the roll of retired officers, and shall thereby be entitled to wear, when not in conflict with the laws or regulations of the United States, on state or other occasions of ceremony, the uniform of the rank last held by him. The Governor may, by general order, provide a suitable mark of distinction for all officers and enlisted men who have served in the National Guard.