English terms with diacritical marks
The Old English Latin alphabet began to replace the Runic alphabet in the 9th century, due to the influence of Celtic Christian missionaries to the Anglo-Saxon kingdoms. The orthography of Old English – which was entirely handwritten in its own time – was not well standardized, though it did not use all the Latin letters, and included several letters not present in the modern alphabet. When reprinted (on a printing press or computer) in modern times, an overdot is occasionally used with two Latin letters to differentiate sounds for the reader:
Persian calligraphy
After the introduction of Islam in the 7th century, Persians adapted the Arabic alphabet to Persian and developed the contemporary Persian alphabet. The Arabic alphabet has 28 characters. An additional four letters were added by Iranians [http://www.persiancalligraphy.org/History-of-Calligraphy.html [2]], which resulted in the 32 letters currently present in the Persian alphabet.