Invisible weapons

Rockett

The other day i accidentally uncovered a way of obtaining items such as swords, bows, shields etc... but these were not ordinary weapons, they all were invisible, they had the animations and everything, but the physical weapon is not shown on your character or to other players.
In your inventory these weapons all function correctly apart from there is no level requirement to wield them. Instead of the image of the weapon in your inventory a image of a question mark is shown instead.

(will add screenshots for evidence of bugged items at a future date)