Arrow Shops:
Each shop only has one of the four elemental arrows:
South Quarter AKA Well Equiped Thief: Water Arrows.
StoneMarket Proper AKA Marla: Moss Arrows.
Docks AKA The Undercurrent: Fire Arrows.
Old Quarter: Gas Arrows.
Fences:
Certain fences only take certain loot. Here are some examples:
Docks fence, AKA Dalia: Artwork