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:
History of the Arabic alphabet
It seems that the Nabataean alphabet became the Arabic alphabet thus:The first recorded text in the Arabic alphabet was written in 512. It is a trilingual dedication in Greek, Syriac and Arabic found at Zabad in Syria. The version of the Arabic alphabet used includes only 22 letters, of which only 15 are different, being used to note 28 phonemes: