AFK farming means the following: Leveling, Item collection, Penya/Perin collection, Leveling weapon/shield, Looting in general.
AFK actually means away from the game/keyboard. This means if you are using an object to hold down your skill to AoE and you walk away from your game, you will be banned. This means that if you are standing around with a pet out and looting other players items, then you will be banned. This also means that if you attack a monster to level your shield and alt tab/walk away from your keyboard, then you will be banned.
Depending on how often you do this or the duration in which you do this action will depend on how long the ban will last. First offense 3 day ban, Second offense 7 day ban, Third will result in a perm. The staff will be the judge on the severity of said punishment.