For seamen and petty officers, which were selected from enlisted men or conscripts and given training in the Navy's service/technical school, the names were different from the army names but were equal in rank. Different service branches within the navy had their specialisation augment the common rank name. For example, Imperial Japanese Navy Air Service (IJNAF) had "Flight" (飛行 "Hikō") incorporated into the common rank name, such as Flight Petty Officer First Class (一等飛行兵曹 "Ittō-hikō-heisō") or Flight Seaman Second Class (二等飛行兵 "Nitō-hikō-hei"). For practical use, these rank names were often shortened to 一飛曹 ("Ippisō") or 二飛 ("Nihi"), respectively. The enlisted rank insignia were changed in April 1942 and the common rank names were updated in November 1942.