From discovery.com: First Islamic Inscription May Solve Qur’an Question.

An Arabic traveler who engraved his name on a block of red sandstone over 1,300 years ago may help solve a question about the Qur’an that has vexed historians for hundreds of years: Why was the text seemingly written without diacritical marks?

Diacritical marks, which include accent marks, tildes, umlauts and other notations, help to distinguish one letter from another and aid in pronunciation. When added or removed, they can completely change the meaning of a word or sentence.

Analysis of the recently found sandstone inscription, which predates the earliest known copies of the Qur’an, determined that it reads: [continue].