iis 7 extended 404 errors Edit
With lot of new enhancements on how the server can control the files/actions, below are the new set of error codes that extend 404 error status.
IIS 7 Extended 404 Errors
404.1
Site not found
404.2
Denied by policy
404.3
Denied by mime map
404.4
No handler
404.5
Request Filtering: URL Sequence denied
404.6
Request Filtering: Verb denied
404.7
Request Filtering: File extension denied
404.8
Request Filtering: Denied by hidden segment
404.9
Denied since hidden file attribute has been set
404.10
Request Filtering: Denied because request header is too long
404.11
Request Filtering: Denied because URL doubled escaping
404.12
Request Filtering: Denied because of high bit characters
404.13
Request Filtering: Denied because content length too large
404.14
Request Filtering: Denied because URL too long
404.15
Request Filtering: Denied because query string too long
That means lot more error handling for you