Do a survey of servername characters

[DanielOaks]

So, the general assumption that I've always had is:

If a 'nick' contains a dot (".") then it's a server name, otherwise it's a nickname.

BUT

Honestly I'm not sure if that's actually true in all cases.

I'd really really like it to be true, it makes things nice and simple, but this is IRC so edge cases abound. Do any real servers out there let you have a server name that doesn't contain a "."? Hopefully none allow nicks that contain ".", but that'd be part of checking this out.