The letter "J" often mentioned by English speaking sources is actually an "I" for "Infanterie" (German for "infantry"). A stamped "I" at the cartridge bottom in writing styles used in the past in Germany could be easily mistaken for a "J". Even in the 21st century the "I" is often substituted by a "J" in English speaking communities and German ammunition manufacturers often write "JS" instead of "IS" to avoid confusing customers. The letter "S" stands for "Spitzgeschoß" ("pointed bullet"), and the English designation "spitzer" for that style of bullet is derived from this German term.