Custom File !

Is the customization file regional or for English Language I can apply any custom file?
Do this file needs to be compatible with FS or Main file?? I need the custom file for my sony ericsson k790i (English Language). Could anyone share his knowledge on this!!
Thanks in Advance!

Every custmization have English language

First of all, as sebak said before, English language comes in all custom files. But they come with more languages included.
If you want to have the languages included in the package, the CDA must be compatible with your FS. Example: FS America 2 - - - > CDA America 2.
If you do not put a compatible CDA, then you will have only English.

Look here:

Languages Description

Nice day

Thanx to all for the knowledge! :)