Hmm. Literacy is a good issue too. To be truly "Points of light in a dark world", you'd want most people to be illiterate. I think I saw somebody's house rule suggesting that you're illiterate unless you're trained in a knowledge skill. Sounds reasonable to me but my players might find it "unfun", so we'll see ... I think literacy is one of those "discuss with the players and go with the flow" things.
@ Zinovia: the 2e Secondary Skill system was an optional variant to the nonweapon proficiency system. It consists of a d100 table with things like armorer, bowyer/fletcher, gambler, mason, miner, scribe, teamster/freighter, weaponsmith, woodcarver/carpenter, etc. Each one has some things you can do with the skill, so like armorer says you can "make, repair & evaluate armor and weapons" while limner/painter says you can do "map making, appraisal of art objects". If you use the table, it is possible to roll one, two or no secondary skills. It then states that "Once a character has a secondary skill, it is up to the player and the DM to determine just what the character can do with it." It goes on to say that, depending on the task, the DM might allow automatic success, assign a percentage chance, or require a saving throw or ability check.