Which is NOT a billet of the Interior Guard?

The term "Soldier of the Guard" is not a recognized billet within the structure of the Interior Guard. The Interior Guard typically includes specific roles that are standard within military operations, specifically designed to maintain security and discipline within certain areas, such as a military installation.

The recognized billets—Corporal of the Guard, Commander of the Guard, and Sergeant of the Guard—are all essential roles with defined responsibilities. The Corporal of the Guard supervises the soldiers assigned to the guard duty, ensuring adherence to protocol and procedures. The Sergeant of the Guard typically oversees the overall operations of the guard detail and reports directly to the Commander of the Guard, who is responsible for the entire guard operation. In contrast, the term "Soldier of the Guard" does not align with official terminology used in military contexts, which is why this option is identified as not fitting within the established hierarchy or structure of the Interior Guard.