Greek alphabet from which the later standard Greek alphabet emerged. Athens used a local form of the "light blue" alphabet type until the end of the fifth century BC, which lacked the letters Ξ and Ψ as well as the vowel symbols Η and Ω. In the Old Attic alphabet, stood for and for . was used for all three sounds (correspondinɡ to classical respectively), and was used for all of (corresponding to classical respectively). The letter (heta) was used for the consonant . Some variant local letter forms were also characteristic of Athenian writing, some of which were shared with the
Greek alphabet an additional diacritic in certain words, the so-called iota subscript, which has the shape of a small vertical stroke or a miniature below the letter. This iota represents the former offglide of what were originally long diphthongs, (i.e. ), which became monophthongized during antiquity. Another diacritic used in Greek is the diaeresis (), indicating a hiatus. This system of diacritics was first developed by the scholar Aristophanes of Byzantium ( 257 – 185/180 BC), who worked at the Musaeum in Alexandria during the third century BC. Aristophanes of Byzantium also was the first to divide poems into lines, rather than