It is the one item slot that does almost nothing.
There are exactly 2 quivers that drop in game: Quivering and Alacrity.
The so called Ranged Pass seems to have completely overlooked this, which is no surprise since the item slot is so worthless that nobody ever thinks of them. But the item slot is there doing nothing.
Therefore, I suggest making a Cannith Craftable quiver that uses the same magical prefix and suffix as a trinket.