It should be clarified, this AN, AG, or Never is based on a per item type basis! If you come across an item you have never seen before, it will give you the prompt asking if you want to do.
The full options are:
Need = You are selecting just this once to roll as Need for the selected item
Greed = You are selecting just this once to roll as Greed for the selected item
Decline(?) = You are declining the item just this once
Always Need = For this and every subsequent time this item comes up, you will roll Need for that item type
Always Greed = For this and every subsequent time this item comes up, you will roll Greed for that item type
Never = You will ALWAYS decline this item type.
Bone Chips for example, set to AG (always greed). You will automatically roll vs anyone else greeding them forever. If you don't want them, select Never and you will never see a bone chip ever again. If someone else has selected Need, you won't even bother with a Greed roll and it will be given to that person. If more than 1 person Needs, then a Need roll is made to determine who gets it.