0.9,th-th

: This identifies the language as Thai ( th ) and the region as ( TH ).

: If English isn't available, it serves the Thai version because it has the next highest weight ( q=0.9 ). 0.9,th-TH

: Developers use these strings to match user OS settings with available translation files. : This identifies the language as Thai (

The string breaks down into two distinct parts defined by the HTTP/1.1 specification : The string breaks down into two distinct parts

When a web browser sends a request, it might include a header like: Accept-Language: en-US, th-TH;q=0.9

: Used by clients to request specific data formats or localized error messages from RESTful APIs. Summary Table: Component Meanings th Language Code ISO 639-1 code for Thai TH Region Code ISO 3166-1 alpha-2 code for Thailand 0.9 90% weight ; high priority but not the absolute first choice

The server analyzes this list to determine which version of a page to serve: