Shan is the twenty-first letter of the Samaritan alphabet and carries the numeral value three hundred. It writes the sh sound. The name is the inherited Northwest Semitic one behind Hebrew shin, glossed as a tooth, a reading reconstructed from the word.
This is one of the letters that carries more than one sound of the ancestor language. Two distinct consonants of the earlier system fell together in the alphabet at this point, and the merger is why some words that look unrelated across the Semitic languages are in fact cousins. In the square Hebrew script the ambiguity was eventually handled by adding a dot, placed to the right for sh and to the left for s, a device invented long after the letters themselves. The Samaritan script never adopted it and does not need it, because the reading tradition supplies the distinction.
Greek took a sign in this area as sigma, but the sibilants crossed over in the borrowing: the Greek letter that inherited this shape took its name from a different Semitic letter, and the tangle has been argued about for a long time without a settled result. It is a rare case of the Greek adaptation, elsewhere so regular, being genuinely confused.
The character is encoded at U+0814.