I am just about ready to upload my first application to the app store D). I've started looking at the steps required to add a new application to iTunes Connect and the only thing that doesn't make sense to me is the SKU. The documentation just says "Unique Stock Keeping Unit (SKU) for each major version of your application". So is this just a number I make up? Or is there some (no doubt complicated) process I am expected to complete to generate it?