As with every technical system, errors occur in the WWW as well. Here are the most common errors you will see:

 400 - Bad Request            - Ungültige Anforderung
 401 - Authorization Required - Authentifizierung benötigt
 403 - Forbidden              - Zugriff verboten
 404 - File Not Found         - Dokument nicht gefunden
 500 - Internal Server Error  - Interner Server Fehler

For the most common "404 - File Not Found", the following screen will be displayed:

If the standard messages do not fit your needs, you can create your own error messages.
Simply create a subdirectory named /errors in your domain root directory. This directory is the location for your new error messages.
Error documents have no extension. E.g. your own 404 error document would have the complete path /errors/404. ( /usr/home/domainname.com/errors/404 in the MicroRack context.)