The following codes show up in your IIS WWW log files:
Common WWW Response Codes
 
   -- they may be replaced by local equivalents without affecting the
   protocol.

          Status-Code    = "100"   ; Continue
                         | "101"   ; Switching Protocols
                         | "200"   ; OK
                         | "201"   ; Created
                         | "202"   ; Accepted
                         | "203"   ; Non-Authoritative Information
                         | "204"   ; No Content
                         | "205"   ; Reset Content
                         | "206"   ; Partial Content
                         | "300"   ; Multiple Choices
                         | "301"   ; Moved Permanently
                         | "302"   ; Moved Temporarily
                         | "303"   ; See Other
                         | "304"   ; Not Modified
                         | "305"   ; Use Proxy
                         | "400"   ; Bad Request
                         | "401"   ; Unauthorized
                         | "402"   ; Payment Required
                         | "403"   ; Forbidden
                         | "404"   ; Not Found
                         | "405"   ; Method Not Allowed
                         | "406"   ; Not Acceptable
                         | "407"   ; Proxy Authentication Required
                         | "408"   ; Request Time-out
                         | "409"   ; Conflict
                         | "410"   ; Gone
                         | "411"   ; Length Required
                         | "412"   ; Precondition Failed
                         | "413"   ; Request Entity Too Large
                         | "414"   ; Request-URI Too Large
                         | "415"   ; Unsupported Media Type
                         | "500"   ; Internal Server Error
                         | "501"   ; Not Implemented
                         | "502"   ; Bad Gateway
                         | "503"   ; Service Unavailable
                         | "504"   ; Gateway Time-out
                         | "505"   ; HTTP Version not supported
                         | extension-code

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The following codes show up in your IIS FTP log files:
Common FTP Response Codes
			| "230"   ; User logged in, proceed
			| "331"   ; User name okay, need password
                        | "530"   ; Not logged in

                        
References from Microsoft, http://www.w3.org/Protocols/rfc959/4_FileTransfer.html, etc.

Commandline Media