The quiver window is used to store and select arrows for non archer type characters that can use a bow.
The window will appear when you click on the button labeled "Quiver" in the Main Menu or Command windows of the User Interface. To change the arrow type left click on the arrow icon. The highlighted bar will move to indicate which arrow type is currently selected. Left click on the quiver window name when available to toggle the Armor Resist window.
There is nothing shown when the window is concealed. The window is invisible with no graphics or controls to minimize the amount of memory used. Nothing will appear on the screen when you attempt to activate the window.