: If English isn't available, it serves the Thai version because it has the next highest weight ( q=0.9 ).
: This identifies the language as Thai ( th ) and the region as ( TH ).
: Developers use these strings to match user OS settings with available translation files. 0.9,th-TH
When a web browser sends a request, it might include a header like: Accept-Language: en-US, th-TH;q=0.9
: Often written as q=0.9 , this is a Relative Quality Factor . It ranks user preferences on a scale from 0.0 to 1.0. A value of 0.9 indicates it is a secondary preference if a primary language (defaulting to q=1.0 ) is unavailable. 2. Practical Application: How Servers Use It : If English isn't available, it serves the
The server analyzes this list to determine which version of a page to serve:
While primarily used in HTTP, this syntax appears in other technical environments: When a web browser sends a request, it
: 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
