What does 403 error really mean?

            Every request get a status message from the server, 403 means 'Access Forbidden'. But what most of us don't know is the meaning of its sub-status. Below list gives us a clear idea of what it really means

• 403.1 - Execute access forbidden.
• 403.2 - Read access forbidden.
• 403.3 - Write access forbidden.
• 403.4 - SSL required.
• 403.5 - SSL 128 required.
• 403.6 - IP address rejected.
• 403.7 - Client certificate required.
• 403.8 - Site access denied.
• 403.9 - Too many users.
• 403.10 - Invalid configuration.
• 403.11 - Password change.
• 403.12 - Mapper denied access.
• 403.13 - Client certificate revoked.
• 403.14 - Directory listing denied.
• 403.15 - Client Access Licenses exceeded.
• 403.16 - Client certificate is untrusted or invalid.
• 403.17 - Client certificate has expired or is not yet valid.

Source: www.wikipedia.org