History of the Greek alphabet only required one. The history here is complicated, but basically "sāmekh" dropped out in certain dialects, and was reused to represent in others, while usage for the sound varied between "ṣādē" and "šin". The letter now known as sigma took its name from "sāmekh" but its form from "šin", while the letter San, which occurred in a few dialects only, took its name from "šin" but its place in the alphabet from "ṣādē". A further Greek letter of uncertain origin, sampi, is found occasionally, and may represent an affricate, such as . For the special case of zeta, see Zeta
History of the alphabet that are not used as national scripts today, a few are clearly independent in their letter forms. The Zhuyin phonetic alphabet derives from Chinese characters. The Santali alphabet of eastern India appears to be based on traditional symbols such as "danger" and "meeting place", as well as pictographs invented by its creator. (The names of the Santali letters are related to the sound they represent through the acrophonic principle, as in the original alphabet, but it is the "final" consonant or vowel of the name that the letter represents: "le" "swelling" represents "e", while "en" "thresh grain" represents "n".) In