in the retail industry it means that a product is not being made anymore
but yes you are right it also denotes that an item is "new and never sold" I guess thats self explanatory if its being sold in a store that doesn't sell used items, which is every sneaker store I've ever been to
when I buy sneakers I assume they are new unless specified. And never off shelf, I don't know what that is supposed to prove, I don't give a fuck if they've ever been off of a shelf, if they're new, they're new
and new items generally come with a box, tag, etc.
on another note my dog ate ONE of my "deadstock" sb trainer 1's that were pretty much the best color that ever came out in trainer 1's period
he got the beating of his life
now if I ever brake one leg or ankle I know what to rock