This thing is called the front cover of a navy hat. Before the seventeenth year of Showa (1942), the Japanese navy hat said its own deployment, which read XX ship, and the artillery technical school was the artillery technical school.

IJN recruits must go to the Marine Corps for training before boarding the ship. At that time, there were mainly Japanese military ports such as Yokosuga, Maihe, Zhenwu and sasebo, and then these recruits were trained by the Marine Corps here. Their hat banners say "XX Marine Corps" and so on.

By 1942, 10/0/30, the Japanese navy changed the seal on the front of the naval cap to Grand imperial japanese navy, fearing that the ship information would be leaked through the naval cap.