Do we know the exact purpose for creating 3 different symbols for each book's metals (chapter symbols)? Is it for the 3 metallic arts? If so, which belong to which?
Hi FireOx! The three sets of symbols show the progression of the Allomantic text through the ages. The earliest script is from Hero of Ages. It was changed and modified into the Terris script symbols we see in Well of Ascension. After more time, the Terris script morphed into what is now known as the Allomantic Alphabet or the Steel Alphabet, which are the symbols used in Mistborn: The Final Empire. We've extrapolated the Steel Alphabet into a script that's more-standardized and refined for the chapter headings in Alloy of Law, which takes place 300 years after Hero of Ages.