After years of doing web-development, I just stumbled on example.com/example.net/example.org second level domain names.
Those are domains meant for documentation or example purposes.
And there is RFC 2606 that documents them.
There are even these first level domain names:
.test/.example/.invalid/.localhost
You’re never too old to learn something new :-)
–jeroen
The Wiert Corner - irregular stream of stuff 