Although the US and several other countries use the initial letter of the city for its mint marks, this practice is not universal. For instance, Germany used A for Berlin, D for Munich, E for Muldenhutten, F for Stuttgart, G for Karlsruhe and J for Hamburg. When Spain adopted decimal coinage in 1848, it used stars with different numbers of points as mint marks. Madrid used six pointed stars, Barcelona used eight pointed stars, and so on. After the revolution of 1868, small dates were placed in these stars. The small dates indicated the year the coin was struck, as opposed to the large date on the coin which was the year it was authorized.