HTTP 406 Not Acceptable indicates the server cannot produce a response matching the client's Accept headers (Accept, Accept-Encoding, Accept-Language, Accept-Charset). The server is saying 'I have this resource, but not in any format you'll accept.' This is part of HTTP content negotiation — the client states preferences, and the server tries to match them.
Response includes the status code, standard headers (including Content-Type), and a small diagnostic JSON body describing the request and returned status.
Simulator URL (copy in the app after load — not a normal link):
https://httpstatus.com/api/status/406
Example request:
curl -i "https://httpstatus.com/api/status/406"