Once it has been activated, the full address of the Third level will be:
It will not be possible to add the www before the name of the Third level.
Therefore by typing the address http://www.thirdlevelname.domainname.xxx, you will get an error page.
http://hosting.aruba.it (correct address of the 3° level)
http://www.hosting.aruba.it (incorrect address of the 3° level)