In post 1920, jeking, I believe it was, gave a link to a site that showed certain variations of a product as "Out Of Stock". This one particular customer (until I talked her out of it) wanted to show every variety of every item she sold even if the stock level was zero so customers could see all the variations she offered. It seems that when an item has originally been entered into SBA with a quantity above zero, it will show in the drop-down as Out Of Stock once the stock has been sold. You cannot, it seems, enter a product into SBA, then when entering quantities, give it a value of zero and have it show up in the drop-down list. I convinced the customer that this was "ill advised" (not the wording I wanted to use) because it would irritate the hell out of a customer to have to look through 30 "Out Of Stock" items just to find out what the heck WAS in stock. There are situations where this would be useful, however. Let's say you're just starting up a T-shirt shop and we'll only stick with one attribute for the moment. Once you get the money, you will be offering sizes from 2T up to 4X, but at the moment all you have is small, medium, large, 1x and 2x. You may want to show the other sizes as choices listed as Out Of Stock since you will be selling them soon and don't want customers to think those are the only sizes you will offer. Now, that may be a lame example, and if you had lots of variations, that could get out of hand quickly and actually drive people away from your site, but, at the time, that is what my customer wanted and the option to do that was not there, that's all.
Mal