Shelfwear or shelf wear
The wear caused by a shelf.
Oh. Wait. I'm not Webster 1913. Shelfwear is usually the damage that occurs to an item once it arrives at a retailer. It can be indistinguishable from, and therefore include damage that occurs to an item during shipping, providing that the damage is not so bad as to preclude retail sale.
Shelfwear generally refers to the scuffing of the outside of an item, most often books or the packaging of an item. Items rub together on the shelves or through handling and are slightly damaged. From a collector's perspective, items without shelfwear are often more desirable than those displaying it, though due to the nature of the materials used and the age of an item, shelfwear may be inevitable.
For some items, shelfwear is inevitable. These include books with extremely glossy dust jackets and large car body parts.
Car body parts do not store easily. They are often formed in irregular shapes and can dent or be scratched easily. It's not uncommon to find a 40 year old part that is "new old stock" but with a few dents and some surface scratching.
I suspect that the handling practices of some book publishers or distributors are somewhat to blame for shelfwear. There are a few titles that I've seen an unusually large proportion of the copies available listed as being shelfworn, far higher than I would expect for the number printed or the quality of materials used in their production. I can't believe that that many copies were simply damaged from sitting around on the shelf.
With regard to books (and other items, of course), shelfwear can be so extensive as to make the item undesirable. Thus, if a book is listed as having extensive shelfwear and the price seems unreasonably low, be cautious.