100 - Continue  101 - Switching Protocols

  Success Codes
  200 - OK
  201 - Created
  202 - Accepted
  203 - Non-Authoritative Information (for DNS)
  204 - No Content
  205 - Reset Content
  206 - Partial Content

  Redirection Codes
  300 - Multiple Choices
  301 - Moved Permanently
  302 - Moved Temporarily
  303 - See Other
  304 - Not Modified
  305 - Use Proxy
  307 - Redirect Keep Verb

  Failure Codes
  400 - Bad Request
  401 - Unauthorized
  402 - Payment Required
  403 - Forbidden
  404 - Not Found
  405 - Bad Request
  406 - Not Acceptable
  407 - Proxy Authentication Required
  408 - Request Timed-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

  Server Error Codes
  500 - Internal Server Error
  501 - Not Implemented
  502 - Bad Gateway
  503 - Server Unavailable
  504 - Gateway Timed-Out
  505 - HTTP Version not supported

  Internet API Error Codes
  12001 - Out of Handles
  12002 - Timeout
  12003 - Extended Error
  12004 - Internal Error
  12005 - Invalid URL
  12006 - Unrecognized Scheme
  12007 - Name Not Resolved
  12008 - Protocol Not Found
  12009 - Invalid Option
  12010 - Bad Option Length
  12011 - Option not Settable
  12012 - Shutdown
  12013 - Incorrect User Name
  12014 - Incorrect Password
  12015 - Login Failure
  12016 - Invalid Option
  12017 - Operation Cancelled
  12018 - Incorrect Handle Type
  12019 - Inccorect Handle State
  12020 - Not Proxy Request
  12021 - Registry Value Not Found
  12022 - Bad Registry Parameter
  12023 - No Direct Access
  12024 - No Content
  12025 - No Callback
  12026 - Request Pending
  12027 - Incorrect Format
  12028 - Item Not Found
  12029 - Cannot Connect
  12030 - Connection Aborted
  12031 - Connection Reset
  12032 - Force Retry
  12033 - Invalid Proxy Request
  12034 - Need UI
  12035 - Not Defined in WinInet
  12036 - Handle Exists
  12037 - See Cert Date Invalid
  12038 - See Cert CN Invalid
  12039 - HTTP to HTTPS on Redir
  12040 - HTTPs to HTTP on Redir
  12041 - Mixed Security
  12042 - Chg Post is Non Secure
  12043 - Post is Non Secure
  12044 - Client Auth Cert Needed
  12045 - Invalid CA (Cert)
  12046 - Client Auth Not Setup
  12047 - Async Thread Failed
  12048 - Redirect Scheme Changed
  12049 - Dialog Pending
  12050 - Retry Dialog
  12052 - Https Http Submit Redir
  12053 - Insert Cdrom
  12171 - Failed DueToSecurityCheck

  FTP API Error Codes
  12110 - Transfer in Progress
  12111 - FTP Dropped
  Gopher API Error Codes
  12130 - Protocol Error
  12131 - Not File
  12132 - Data Error
  12133 - End of Data
  12134 - Invalid Locator
  12135 - Invalid Locator Type
  12136 - Not Gopher Plus
  12137 - Attribute Not Found
  12138 - Unknown Locator
  HTTP API Error Codes
  12150 - Header Not Found
  12151 - Downlevel Server
  12152 - Invalid Server Response
  12153 - Invalid Header
  12154 - Invalid Query Request
  12155 - Header Already Exists
  12156 - Redirect Failed
  12157 - Security Channel Error
  12158 - Unable to Cache File
  12159 - TCP/IP not installed
  12160 - Not Redirected
  12161 - Cookie Needs Confirmation
  12162 - Cookie Declined
  12168 - Redirect Needs Confirmation
  Additional Internet API Error Codes
  12157 - Security Channel Error
  12158 - Unable To Cache File
  12159 - Tcpip Not Installed
  12163 - Disconnected
  12164 - Server Unreachable
  12165 - Proxy Server Unreachable
  12166 - Bad Auto Proxy Script
  12167 - Unable To Download Script
  12169 - Sec Invalid Cert
  12170 - Sec Cert Revoked