The history of ISL goes back to 1873 in Germany, where Marcus Reich, a German Jew, opened a special school for Jewish deaf children.
At the time, it was considered one of the best of its kind, which made it popular with Jewish deaf children from all over the world as well as non-Jews.
During the 1940s, Shassi became the language of a well-established community of Jewish deaf people in Jerusalem and Tel Aviv.
The correspondences are as follows: Unexpected correspondences are ASL 'F' for Hebrew ט tet (analogous to Greek theta becoming Cyrillic fita), '1' rather than 'U' or 'V' for ו vav, old-fashioned 'C' and 'K' rather than 'K' and 'Q' for כ kaf and ק qof (both are pronounced like an English 'k' or hard 'c'), '3' for צ tsade (its cursive form quite resembles the Arabic numeral 3), and 'W' for ש shin (reflecting its shape).
If needed, one may indicate the final forms of letters, ך ם ן ף ץ, by moving the hand downward.