'''For the curious:'''

So, what did this do? Well, what it did was add a [http://httpd.apache.org/docs/current/mod/core.html#serveralias ServerAlias] directive to the Apache configuration. (In MS-IIS, it's called a host header or a binding.) You can have as many ServerAlias' as you'd like. So, if you wanted to take a look under the hood, you would open a terminal window on your server (or SSH to it) and do a directory listing of '''/etc/httpd/conf.d/'''.

user@ubuntu-amahi1:~$ ls -l /etc/httpd/conf.d/

total 28

-rw-rw-r-- 1 www-data users 489 Oct 10 21:18 1002-subsonic.conf

user@ubuntu-amahi1:~$

In our case, when we installed the Dokuwiki app, it created '''1000-dokuwiki.conf'''. Open that and you'll see the ServerAlias that was added.

<VirtualHost *:80>

</VirtualHost>

You can see that adding that ServerAlias added the line: '''ServerAlias wiki.tommy.homedns.org'''