0.9,th-th May 2026

: The server looks for a version in US English ( q=1.0 by default).

: Developers use these strings to match user OS settings with available translation files. 0.9,th-TH

The string breaks down into two distinct parts defined by the HTTP/1.1 specification : : The server looks for a version in US English ( q=1

When a web browser sends a request, it might include a header like: Accept-Language: en-US, th-TH;q=0.9 : If neither is found, the server provides

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

: If neither is found, the server provides its own default language. 3. Contextual Variance

: 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