Skill description: Reduces the chance of obtaining HQ items to 0% but increases item yield by one or two. Number determined by your perception rating. Does not increase item yield if all gathering node items start at 0%.

I've seen some +3, as in the item will have no number next to it to signify one per gather but will show a four after the skill is used. The nodes don't have a gathering yield increase either.

What's the trigger?