0.9,th-th -

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

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

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

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

Are you looking to or analyze its impact on SEO and localized content delivery ? : The server looks for a version in US English ( q=1

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

: This identifies the language as Thai ( th ) and the region as ( TH ). 0.9,th-TH

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