Davos Seaworth, The Onion Knight, is a ‘Ser’ and he was illiterate until Shireen taught him to read. We saw Bronn become a “Ser” and while I don’t know for sure his level of literacy, he was not given a formal education coming up from the streets. I don’t think education is really high on the aptitude list for becoming a ‘Ser’.
Heh. I watch with CC on – it appears some Maester issued an annulment to a Prince “Ragger.”