means it is CARRIER or SIM unlocked, ie use it with T-mobile or other GSM carrier worldwide. Bought 5 outright, all SIM unlocked, one for myself, one for my folks, 3 for friends and family abroad who would appreciate it.
It would sell rather well in Europe; i have already been asked to get several more and unlock them, but i dont want to rock the boat with AT&T (i possess two grandfathered unlimited data plans). I told AT&T manager i wanted spares as i was going abroad to film (which is true) hence multiple units, and multiple unlock requests.
if i did NOT have the unlimited data plan, my bill would hover around $650-800 a month sometimes; i work in film and advertising, so constantly streaming or downloading and screencasting HUGE files. AT&T has always been accommodating and fair, so i try to reciprocate and be respectful.