Job quests, could be a quest line, do you go to say the LNC guild (if guilds is where you get the quests) and you go through a mini story of say 5 quests to unlock a job, the first 4 are honing you abilities so you (in lore terms) are strong enough to be trained in the way of the job.

If they are doing it this way then they could have 4 job quests for each guild, without having the jobs ready.