I agree, @claloano should use good old english/ISO country abbreviations and linux directory structures for any added languages if using Asterisk/FreePBX, the audio content of the file is immaterial
Ref :-
always use iso 639-1 2 letter codes under /var/lib/asterisk/sounds/ (that is pretty well hardcoded under ASTVARLIBDIR/sounds/, as defined in your /etc/asterisk/asterisk.conf file)
but of course you can add ko for Klingon