Indeed, there is a prohibition on the books that bans using the traditional Hebrew script for mundane matters. This prohibition is codified by Rabbeinu Yerucham (Nesiv 2, §50) and by Rama (Yoreh Deah §284:2). Rama (Teshuvos HaRama §34) is inclined to rule that one can treat Torah materials written in the popular script differently than an actual Torah scroll because the former is not written in the real Ashuri and is therefore not as holy as a Torah scroll. However, Rabbi Aharon HaKohen of Lunel adds (Orchos Chaim, Hilchos Talmud Torah §9) that for this reason the Sephardic Jews traditionally write in a script that is different enough from traditional Ashuri that it can be considered an entirely different script. They use what is colloquially known as “Rashi Script” (which is a misnomer because the script has nothing to do with Rashi).
SOURCE: R.C. Klein, Lashon HaKodesh: History, Holiness, & Hebrew (Mosaica Press, 2015), p. 203