Type ( designation ) The word Type followed by a number is a common way to name a weapon or product in a production series , similar in meaning to " Mark " . " Type " was used extensively by the Japanese and Chinese militaries beginning in the 1920s , and is still in current use by the Chinese military . The United Kingdom uses a type number system for much of their military equipment . Many other nations use the word " Type " to designate products in a series . Japan . The Imperial Japanese Navy ( IJN ) began using the Type - Number System in 1921 to designate aircraft accepted for production . The numbers used after the word " Type " were based on the number of years that the Emperor Taishō had reigned . Since his reign began in 1912 , an aircraft ordered into production in 1921 would have been called " Type 10 " , the tenth year of the emperor ' s reign . At the end of 1926 , the emperor died , leaving his son Hirohito as the Emperor Shōwa , and the numbering system was reset to mark the new emperor ' s reign . In 1929 , the government of Japan adopted a new system based on the imperial year . Aircraft ordered for production from 1929 onward were assigned the last two digits of the year marking the continuity of Japanese emperors . 1929 was the 2589th imperial year , so aircraft ordered that year were designated " Type 89 " . 1940 was the 2600th year , and the IJN numbering system was reset to single digits . New aircraft were designated 0 ( zero ) . The well - known Mitsubishi A6M Zero was ordered into production in 1940 as the IJN " Type 0 Carrier Fighter " ( " Rei shiki Kanjō sentōki " , 零式艦上戦闘機 ) , and was popularly called the " Zero " because of its type . In 1943 , the designation system was abandoned by the IJN as it was considered too revealing about the nature of the aircraft . In its place , the aircraft were named with popular terms such as " Kyōfū " ( 強風 " Strong Wind " ) for the Kawanishi N1K introduced in 1943 . The Imperial Japanese Army ( IJA ) began using the Type designation system in 1927 , for all weapons , vehicles , military equipment , subassemblies and subsystems such as engines and gunmounts . In 1940 , instead of resetting to zero , the IJA assigned " Type 100 " to equipment put into production that year . In 1941 , the IJA reset to " Type 1 " . Unlike the IJN , the IJA continued to use the system through 1945 with the production of the Kawasaki Ki - 100 Army Type 5 Fighter . After 1945 , Japan ' s military changed to a numbering system based on the Japanese fiscal year which begins on April 1 in the same manner as the British fiscal year . As an example , " Type 63 " was the designation for equipment such as the Type 63 AT mine accepted in 1963 . The kanji character " shiki " ( しき ) is what the Japanese use to designate products in a series . The English language translation of " shiki " has been variously given as " model " or " type " . Some manuals and texts have translated " shiki " as both " model " and " type " within the same publication , confusing the matter . World War II - era military dictionaries do not give " shiki " as the Japanese word for " model " — instead , the kanji character " kata " is given . In turn , " kata " ( 型 or 形 ) is translated as " form " , " type " , " pattern " , " mark " , or " model " . The only Japanese language translation given for the English word " type " is " shiki " . China . Chinese weapons and military vehicles are often , but not always , designated according to the Gregorian calendar , the one used by most nations . Two digits are used to designate the year . The two digits appear first , followed by the character " shi " , meaning " type " . As examples , in 1956 , the Type 56 assault rifle was put into production , and the Type 64 pistol was designed and approved in 1964 . United Kingdom . The Royal Navy uses a type number system where blocks of numbers are reserved for specific purposes . For instance , the block 900 – 999 was given to naval radar sets beginning in 1945 and continuing for roughly 20 years . Numbers are not always sequential , as the Type 992 target indication radar was developed long before the Type 967 target designation radar . When a reserved block has been fully utilized , another is assigned .