Көне грек әліпбиінің Сан әрпі (San әрпі)

Archaic letter of the Greek alphabet

San (Ϻ) was an archaic letter of the Greek alphabet. Its shape was similar to modern M or Mu, or to a modern Greek Sigma (Σ) turned sideways, and it was used as an alternative to Sigma to denote the sound Unlike Sigma, whose position in the alphabet is between Rho and Tau, San appeared between Pi and Qoppa in alphabetic order. In addition to denoting this separate archaic character, the name San was also used as an alternative name to denote the standard letter Sigma.

A unique letter variant, shaped (similar to modern Cyrillic И, but with a slight leftward bend) has been found in a single inscription in the Arcado Cypriot dialect of Mantineia, Arcadia, a 5th century BC inscription dedicated to Athena Alea (Inscriptiones Graecae V. ii.262) It is widely assumed to be a local innovation based on San, although Jeffery (1961) classes it as a variant of Sigma. It appears to have denoted a sound and has been labelled "Tsan" by some modern writers.

In modern editions and transcriptions of ancient Greek writing, San has rarely been used as a separate letter. Since it never contrasts systematically with Sigma except in abecedaria, it is usually silently regularized to Sigma in modern editorial practice. In the electronic encoding standard Unicode, a pair of uppercase and lowercase forms of the letter was introduced in version 4.0 (2003). For this purpose, new lowercase forms for modern typography, for which no prior typographic tradition existed, had to be designed. Most fonts have adopted the convention of distinguishing uppercase San from Mu by having its central V like section descend only halfway down above the baseline, and lowercase San by giving it a left stem descending below the baseline. (Note that in historical epigraphic practice it was the other way round, with San being symmetrical and Mu having a longer left stem.)

San is encoded in Unicode, while the Arcadian "Tsan" variant is unified with the identical looking Pamphylian Digamma since version 5.1.