It's the panel with the barcode and the other sticker. I took a photo of mine with my N900 for reference, and then peeled off the outer layer of the box. It didn't completely destroy the nice box that way, and doesn't make an unsightly and hard-to-mail envelope.

You have to give your login name for Ovi. No need to do more than sign up for an Ovi account on the webpage and include your username.