After upgrading to an iPhone 6, I'm going to be selling my purchased-on-contract Verizon iPhone 5. As I understand it, the Verizon-model iPhone 5 can accept SIM cards from all GSM and most CDMA carriers. Is it accurate to advertise the iPhone 5 as unlocked, or are there some restrictions on usage? If there is any type of lock or restriction, how do I go about getting the phone completely unlocked (the contract has expired)? Thanks!