International uniformity of braille alphabets

[1] Unification was first achieved by a convention of the International Congress on Work for the Blind in 1878, where it was decided to replace the mutually incompatible national conventions of the time with the French values of the basic Latin alphabet, both for languages that use Latin-based alphabets and, through their Latin equivalents, for languages that use other scripts.

A second round of unification was undertaken under the auspices of UNESCO in 1951, setting the foundation for international braille usage today.

Braille arranged his characters in decades (groups of ten), and assigned the 25 letters of the French alphabet to them in order.

The 1878 congress, convening representatives from France, Britain, Germany, and Egypt, decided that the original French assignments should be the norm for those countries: Gradually the various reordered and frequency-based alphabets fell out of use elsewhere as well.

The additional letters of the extended French Braille alphabet, such as ⠯, are not included in the international standard.

[11] Ethnologue 17 reports braille use for Mòoré (in Burkina Faso), Rwanda, Rundi, Zarma (in Niger), and Luba-Sanga, but provides few details.

In 1929 in Paris, the American Foundation for Overseas Blind sponsored a conference on harmonizing braille among languages which use the Latin script, which had diverged in the previous decades.