I'm testing some scripts on a french server. (irc.voila.fr)
It's not a server I'm usually connecting to, but their system is a good subject of study for some of my scripts.

If you want to test it, unfortunately the server requires authentication with a unique key. Key that must be retrieved from they web server.

Their server automatically rewrites the "user" part of the fulladdress: !guest@ for non-registered nicks, and several variations (based on the level of confidentiality) for registered users. It's the second type that breaks the rule of max 9 (10) chars of length.

Here is an example of a fulladdress (one of their ircops):
artio!000Znowhere@520.681....