This is a pretty interesting article. Honestly, most articles I've seen from Atlas Obscura are interesting enough, one way or another, and anyone involved in any kind of world-building (ie most game masters) should be scouring their website for ideas. But back to this particular article...
So, if you didn't read the article yet, the gist of it is basically that different handwriting styles (fonts if you will) were used in the 17th-18th centuries by different people and for different purposes. One type of script was used for religious documents, one for legal documents, merchants used fairly showy but quickly written script, high-born ladies used showy but very slow-to-write script (they had time to kill). And the game-related light bulb that flashed on in my head said that this might form some sort of clue in an RPG mystery.
A PC cleric might recognize an anonymous written threat as being in the ecclesiastic script, obviously coming from some priest or monk used to copying prayerbooks or whatnot. Or maybe an NPC who is supposedly a cleric writes a note to the PCs using an arcane script suited for magic-user spellbooks, showing that he is not who he seems to be. Clerics would recognize religious scripts, magic-users would recognize the arcane scripts, characters with noble or merchant backgrounds would recognize others of the same background, and thieves would know about them all. Oh yeah, they're all about forging documents and translating maps and dusty old books telling of lost treasures; handwriting analysis of this type is right up a thief's alley. Fold it in under their Read Languages ability, if nothing else...probably with a bonus, because if you can follow along in a book of legends from halfway around the world, picking out a rich merchant's handwriting from an impoverished scholar's in your own native language is a cakewalk.