How to check the firmware region??

[EGY_falcon]

I have Sony Xperia L - Android 4.2.2 - 15.3.A.1.17 firmware
I have rooted it ( for the first time) 2 days ago
Now I want to make a full factory reset to return to it original state, someone had told me that the only way to do that is to flash stock firmware.
I had already downloaded a firmware, but had read some threads of people flashed a firmware with wrong region.
The question is :
How to ensure that this firmware region is mine??

[Uliwooly]

just like your previous post 

http://talk.sonymobile.com/t5/Xperia-L/bootloader-unlock-allowed-BLANK/m-p/676977#M12001

same service menu 

[EGY_falcon]

Ok, but how?
I don't understand what's written.
How to now the region using this menu?

[EGY_falcon]

How to Know*

[Uliwooly]

Use the search bar, and you will find the answer

http://talk.sonymobile.com/t5/Xperia-P/how-to-find-my-xperia-s-country-region/m-p/317947/highlight/t...

[EGY_falcon]

He didn't mention how to know the region using SI number.
My SI : 1271-4573.7

[Uliwooly · Accepted solution]

either contact a Sony moderator or contact your local Sony Xperia care (phone, live chat, email) or check the XDA forum 

[Uliwooly]

it seems that you had either flashed your phone or unlocked your bootloader; if you flashed a different firmware/ftf file, you will only be able to find the region of the latest firmware not the original firmware