Invented by Louis Braille, braille cells were arranged in numerical order and assigned to letters of the French alphabet. Most braille alphabets follow this assignment for the 26 letters of the basic Latin alphabet, or for the equivalents of those letters in a non-Latin script.
The first ten braille letters are ⠁⠃⠉⠙⠑⠋⠛⠓⠊⠚, usually assigned to the Latin letters a–j. The next ten repeat that pattern with the addition of a dot at the lower left, the third ten with two dots on the bottom, and the fourth with a dot on the bottom right. The fifth decade is like the first, but shifted downward. Many languages which use braille letters beyond the basic 26 for simple letters in their script follow an approximation of the English values for the additional letters.