I am confused in reading post topics like UK version and USA version, now there are both running 1.1.2, bootloader 4.x, is there any difference?

with the new US phones (1.1.2 with bl 4.6) no difference - none found so far anyway...

but as there are some cases of US iPhone with 1.1.2 and bl 3.9 plus so many older ones, it helps when indicated exactly which it is...

I just got a US 1.1.2 OTB, can i find out the version of its bootloader?

if its a week 43 or above then its almost 99% going to be 1.1.2 with BL 4.06

I see , thanks, my one is of week 45.