It's the ReqIg field for an item that alters the cooldown. Just be aware that the number entered is not "minutes" but rather the group the item's cooldown belongs to. If that doesnt make any sense, you can also refer to
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This was specifically about Skill Reset Stones, but the last post has some good info on the ReqIg field.
If you do not have Tommo's file linked in the above post, I would highly recommend getting and keeping it as reference.