The first surviving document that definitely uses these dots is also the first surviving Arabic papyrus (PERF 558), dated April, 643. The dots did not become obligatory until much later. Important texts like the Qur'an were frequently memorized; this practice, which survives even today, probably arose partly to avoid the great ambiguity of the script, and partly due to the scarcity of books in times when printing was unheard-of in the area and every copy of every book had to be written by hand.
