TIL 404 errors actually have more specific causes
POSTED ON:
404 - Not found.
But did you know this?
404.0 - Not found.
404.1 - Site not found.
There's actually a huge list of these substatus codes!
Not just for 404s, but also for 400, and 500!
Just to showcase an example:
The IIS list for 404s #
IIS 7.0 and later versions define the following HTTP status codes that indicate a more specific cause of an error 404:
404.0 - Not found.
404.1 - Site Not Found.
404.2 - ISAPI or CGI restriction.
404.3 - Multipurpose Internet Mail Extensions (MIME) type restriction.
404.4 - No handler configured.
404.5 - Denied by request filtering configuration.
404.6 - Verb denied.
404.7 - File extension denied.
404.8 - Hidden namespace.
404.9 - File attribute hidden.
404.10 - Request header too long.
404.11 - Request contains double escape sequence.
404.12 - Request contains high-bit characters.
404.13 - Content length too large.
404.14 - Request URL too long.
404.15 - Query string too long.
404.16 - DAV request sent to the static file handler.
404.17 - Dynamic content mapped to the static file handler via a wildcard MIME mapping.
404.18 - Querystring sequence denied.
404.19 - Denied by filtering rule.
404.20 - Too Many URL Segments
404.501 - Not Found: Too many requests from the same client IP; Dynamic IP Restriction Concurrent request rate limit reached.
404.502 - Not Found: Too many requests from the same client IP; Dynamic IP Restriction Maximum request rate limit reached.
404.503 - Not Found: the IP address is included in the Deny list of IP Restriction
404.504 - Not Found: the host name is included in the Deny list of IP Restriction
Related TILs
Tagged: trivia