I do not work for OTB

... but this is what I understand...
OTB is "out of the box". If your phone is 1.1.2 OTB, it means it was on 1.1.2 when you unboxed it. It yours is NOT 1.1.2 OTB, then it means that you UPGRADED it to 1.1.2 from whatever the earlier version was.
Mine is NOT 1.1.2 OTB, and my modem firmware version is 04.02.13_G. But I cannot say what difference that makes.
I read on some post somewhere that there's something called a boot-loader version. If the version is old, then you can use sotware-based unlocking utilities. If it is newer, you don't have any option other than hardware-based unlocking utilities. Like either using a double-sim, or cranking your iphone open.
That could mean that non OTB 1.1.2 phones have an older boot-loaders, and so you can software-unlock them. But I am not very sure of that.
So, now you at least know what OTB is, and why it is so important in your daily life.