LITERACY LIMITATIONS
If a character speaks a language, it cannot always be assumed that he can read and write the language. The ability to read and write is far less common in this game setting than in more advanced settings. Many people raised in civilized lands (The Nadrilian West, The Markelands, Kortella, Pylosean, Esosan, and Voldruv) can puzzle out simple writings they encounter, but intermediate and more advanced writing may be indecipherable to them depending on their upbringing. Those from the barbaric, rural, or less developed lands (Gaeirmund, The Danneinkiff, Ingvael, Korsi, Bishtaan, Heshba, Jbail) are quite likely to be effectively illiterate.
We won't be working with any hard rules or prescriptions of exactly which PCs can read or write, and at what level of proficiency if they can. Players can decide what they will about the character. I just hope to put these ideas forward for consideration. Sometimes a character may be assumed to be literate with the selection of a Proficiency, Skill, Background, Feat that suggests literacy (examples: Proficiency in Calligrapher's / Cartographer's Tools, the Sage Background, the Ritual Caster Feat). Others of certain sub-races with a less suggestive back story and skill set may be illiterate in all likelihood.
That being said, illiteracy is not necessarily the drawback it might be in more advanced settings. People in all known regions expect to interact with a lot of other people who can’t read or write, and take appropriate steps. For example, when sending a message, a merchant might actually dictate a message to the runner instead of handing him a written note; the runner simply recites the message when he finds the recipient. Even people who can’t read can understand tally marks, or recognize very common symbols such as coin denominations.