Sold out vs. Out of Stock?

What is the difference between sold out and out of stock on the FS website (for standard editions)? For example, Call of Cthulhu SE is sold out but Master and Margarita is OOS. I've read somewhere that this means OOS will be available again soon, but sold out means it won't be (unless it is reprinted in a new edition?).

>1 punkzip: From what I have found (and is the general consensus from this forum), sold out means no plans to reprint, out of stock means there are plans to reprint.

Yes, that's how I understand it as well.

Ulysses for example was listed as sold out for a while, before being removed completely from the website.
The Great Gatsby on the other hand is listed as out of stock with a notice about expected stock: https://www.foliosociety.com/row/the-great-gatsby.html

Sold out doesn't mean you wont ever see it again, it just means that if you will, it will be a second print or a new edition.

Booksellers love to see the FS website showing 'Sold out' as it means devotees will have to purchase their modestly priced books from them at long last.

'Out of stock' ... not so much.