I was given a MSL code for unlocking my IPhone 5 upon termination stating other carriers will unlock upon providing the same but other carriers don't know how to unlock my using that code.Will Apple unlock if under warranty period?

Harrison_Taylor wrote:

the only thing I am saying is that Verizon does not prohibit non VZW devices on their network,

No one has argued with that premise .

Even in the days of flashing/ESN cloning Verizon still widely encouraged it as it was a way for them to penetrate a deeper market, Japan and China operate CDMA networks on the same bands as Verizon and China Telecom, a Chinese CDMA network, welcomes Sprint/Verizon iPhones with open arms.

No, Verizon never encouraged that. It has never been possible to activate a non-Verizon CDMA phone through a Verizon Store. For a time, Verizon offered a little publicized program where, for a select list of phone models, you could send your phone to Verizon and have it flashed. They projected that you'd get your phone back in about 6 weeks. To date, I've never met anyone who actually took advantage of this program.

What other carriers do or do not do is not germane to what Verizon does. I don't believe anyone else has commented on what carriers in Japan or China do.

No. You're just making a fool of yourself.

That's your opinion.