so, if i want to buy a zte U960 by TaoBao, a cheaper one than Etowalk version, what must I ask to the TaoBao's supplier?
I believe there isn't a good way rightnow, likely they just don't know exactly how (and if) the phone is locked.
What does it mean "unlocked"?
That's the problem, there are a number of different possible locks on phones, and a phone can be locked in one or more ways.
#1 SIM lock: the phone will accept only one SIM
#2 Operator lock: the phone will accept all the SIMs from a specific provider, is the more common kind of lock
#3 Band lock: the phone will limit the network functionality depending on the sim inserted and/or the region.
For example: my Droid 2 Global (which is a dual standard CDMA/GSM phone ) had two kind of locks, GSM/WCDMA are working only outside the US AND the phone accepted only SIMs from Verizion.
I removed only the latter because the former doesn't affect me (I'm not in the US).
With a dual standard AND dual SIM phone the 3 kind of lock can be applied separately on the two SIMs, so both, asking the question and replying to it, are more complicated matters.
I'm sure the ZTE is band locked for WCDMA on slot 2 for chinese territory, this kind of lock doesn't affect the people living on the rest of the world.
I'm not sure if there is an additional SIM lock on SIM 1, if present this will be a problem (likely a problem easy to solve, but surely a problem).