It is -not- client side. I could send you login and pass for an account with a char like this that you could look at but you can't login to cabal brazil for the IP block. Hack was used only while sending the invalid chars in username, then the char is definitively with that name, until an BD admin change its name, I could logon with any unhacked client and use the char with 'wrong' chars.
Once again, the hack is used just to allow sending the 'custom' ASCII chars. The server accepts it. It is there for good.
Well I deleted the " " char on game to avoid having my account banned, but still using a char with a 'dot' in it.
EDIT: no rename card. As you can see, the char is new, and the name is sent (in the case four ASCII spaces only - 0x20h). I don't think I will ever put my hands in a rename card