510
Not Extended
Server errors (5xx)·RFC 2774·deprecated
What 510 means
Further extensions to the request are required for the server to fulfil it.
Part of the obsolete HTTP Extension Framework; almost never used.
Server errors (5xx)
The server failed to fulfil an apparently valid request.
Other 5xx codes
FAQ — 510
What does HTTP 510 mean?
510 Not Extended: Further extensions to the request are required for the server to fulfil it. Part of the obsolete HTTP Extension Framework; almost never used.
Which class does status code 510 belong to?
510 is a Server errors (5xx) code. The server failed to fulfil an apparently valid request.
Where is the 510 code defined?
Status code 510 is defined in RFC 2774 and is part of the IANA HTTP Status Code Registry.