[Fontconfig] How can I get font list for specific language?

[Deokjin Kim]

Hello,

I want to get font list for specific language.

As I know, font file(*.ttf) has lang info. Below is example.
      lang=bg|ko|kum|os|ru|sel
What's the meaning of above info? 
      bg ==> BULGARIAN
      ko ==> KOREAN
      kum ==> ??
      os ==> ??
      ru ==> RUSSIAN
      sel ==> ??
Is it right infomation?
I can get lang info(lang=bg|ko|kum|os|ru|sel) using modification of fc-list.c, but I don't know exact meaning.
Actually above font file is for korean. But it has not only "ko", but also "bg", "ru" ....

Font file has wrong lang info? Otherwise, my approach is not good?

If you know proper approach, please let me know.

Thank you,
Deokjin Kim