Alongside recipes and special words for potions and magical charms, this manuscript presents a range of charaktêres (ring letters). These special letters are unreadable and unutterable. They discharge their power not when they are read, but when they are written in amulets. The signs probably came from occult traditions in Ptolemaic Egypt (from the 3rd century BC to about 30CE). They appeared in Jewish magical traditions some centuries later.
Renaissance scholars arranged these charaktêres into alphabets, and said they were the language of angels. The idea was to conjure the help of these supernatural beings by communicating with them in their own language.