The Dotted Letter, and Where the Order Stops

Several of the scripts descended from Brahmi later added a subscript dot to this letter to write a sound the inherited inventory had no place for, the voiced sibilant that arrived in the northern languages with Persian and Arabic vocabulary. It is a neat solution and it says something about how these alphabets grow. A new sound does not get a new position in the order, because the order is fixed and recited; it gets a modified form of an existing letter, filed under the letter it modifies. The dotted signs are therefore additions that leave the sequence undisturbed, and a reciter of the alphabet does not have to learn a longer list.

Brahmi itself has no such marks. The inscriptions record what the languages of the third century BCE and the following centuries actually needed, and everything beyond that is a later script's business. The distinction is worth holding onto, because a reader who knows a modern Indic alphabet will recognise most of the Brahmi letters and may reasonably assume the modern refinements go back with them. They do not. The dotted letters, the explicit vowel canceller and several of the conventions for writing clusters are all developments of the descendants, and Brahmi left more to the reader than any of them.