Kufic is the oldest form of the Arabic script. The style emphasizes rigid and angular strokes, which appears as a modified form of the old Nabataean script. The Archaic Kufi consisted of about 17 letters without diacritic dots or accents. Diacritical markings were added during the 7th century to help readers with pronunciation of the Qur'an and other important documents, increasing the number of Arabic letters to 28. Although some scholars dispute this, Kufic script was supposedly developed around the end of the 7th century in Kufa, Iraq, from which it takes its name. The style later developed into several varieties, including floral, foliated, plaited or interlaced, bordered, and square kufic. Due to its straight and orderly style of lettering, Kufic was frequently used in ornamental stone carving as well as on coins. It was the main script used to copy the Qur'an from the 8th to 10th century and went out of general use in the 12th century when the flowing naskh style become more practical. However, it continued to be used as a decorative element to contrast superseding styles.