When you're storing / seasoning timber each row should have smaller timbers placed across them at regular intervals that the next row lays on these smaller timbers are called stickers (at least that's what I was taught there are about a thousand different names for them).
Make sure you weigh it down and sticker it properly or you may well end up with banana shaped timber.
Edit: in all fairness it will probably arrive banana shaped but will get even worse if not stored properly.