HTTP Errors Zoo

Let's look at 5 different URLs below and enjoy 5 different error messages.
1) http://docs.fortinet.com/fgt
2) http://docs.fortinet.com/fgt/
3) http://docs.fortinet.com/fgt/index.htm
4) http://docs.fortinet.com/fgt/index.html
5) http://docs.fortinet.com/fgt/index.php

Go!
1.

2.

3.

4.

5.