quickly went thru the keyboard and found that the following can't be used:

¬ : ; ' ~ , < > . ? / (but \ can be confused) ! " £ $ ^ & * ( ) = @ + %

Tested on unreal 3.2. Might have missed some and unsure about characters such as ú cuz i just closed the ircd as i remembered about them and i'm too lazy to open it up again :tongue: