(output) format settings:

* Number format setting (LC_NUMERIC, C/C++)
* Character classification, case conversion settings (LC_CTYPE, C/C++)
* Date-time format setting (LC_TIME, C/C++)
* String collation setting (LC_COLLATE, C/C++)
* Currency format setting (LC_MONETARY, C/C++)
* Paper size setting (LC_PAPER, ISO 30112)
* Color temperature setting
* UI font setting (especially for CJKV language)
* Location setting (country or region)