I can't believe we're even having this discussion with someone who's had an account since 2011. There are so many ways to tell whether something is an item or a product and none of them contradict one another, nor are they open for individual interpretation. If it's in the product tab of the inventory and it's not a recipe, it's a product. If you hover over an item and it says Product below it's name, it's a product. If it can be equipped in the product slot, it's a product. If it's usable (and again not a recipe), it's a product. Raven feathers are clearly products, not items.