I have a iPhone 5S that I plan to sell on eBay. The 5S was originally on AT&T but I upgraded to the 6+. I filled out the AT&T unlock form and they honored my request. I restored my phone and it is now unlocked. My question is: is it factory unlocked or unlocked? I read through eBay's article but it sounded like it had to come from Apple's factory unlocked in order to be considered factory unlocked?