What does "B-Stock" mean?

I see items for sale with this designation, but don't have any idea what it means about the item.
b stock usually means the item was dead out of the box when new, and sent back to the manufacturer for repair, then repaired, tested, and the box resealed. b stock should come with full warranty and price should be lower.
Tacs is correct, however another characteristic of "B stock" items could be cosmetic blemishes that have nothing to do with the performance of the unit. The manufacturer sells them off cheaper rather than scrapping the unit. Great buys, but...you'll have a tough time selling a blemished unit should you choose to upgrade down the road. Proceed with caution. Jeff
The term also applies to units that were used at shows such as CES or units that were lent to reviewers. There are nothing wrong with these units other than they have been used. They carry a full factory warranty.
It means that the little guys on K-Mex (dressed up in the bee costumes) have partied with this particular piece of equipment. They go through a lot of gear.
Also on occassion they are actually new units that are being cleared out to make room for a new model. In these cases B stock units usually have a shorter warranty period which lowers the company's future warranty repair costs, so they can reduce the price even further to clear them out faster.

You see this a lot with stuff on Ubid.com

I thought the name derived either from being "non-A" stock, or a shortened form of "blem" for blemished.