A locale indicates a particular geographical, political, or cultural region. The Locale specifies the language used in creating ...

A locale indicates a particular geographical, political, or cultural region. The Locale specifies the language used in creating the RecordForLog data. If the Locale property is empty, it is assumed that the default locale is en_US (English). 
The locale string consists of three sub-strings, separated by underscores: 
- The first sub-string is the language code, as specified in ISO639. 
- The second sub-string is the country code, as specified in ISO3166. 
- The third sub-string is a variant, which is vendor specific. 
For example, US English appears as: "en_US_WIN", where the "WIN" variant would specify a Windows browser-specific collation (if one exists). Since the variant is not standardized, it is not commonly used and generally is limited to easily recognizable values ("WIN", "UNIX", "EURO", etc.) used in standard environments. The language and country codes are required; the variant may be empty.