by having the chat control hash the IP address of the server to which it was instructed to connect into the response to the challenge in authentication. If the control was instructed to connect to any address other than the server, it would not match the server's hash and thus authentication would fail. A few later third party clients could authenticate without the control and were adjusted to compensate for this change. Versions The versions of MSN Chat were designed from IRC3 through to IRC8, Even with the newer versions, MSN Chat still had the possibility to replicate older MSN Chat versions by issuing the IRCVERS command. It is believed that IRC referred to the original IRC Daemon, and IRC2 referred to IRCX. IRC3 MSN Chat 1.0 was introduced as an ActiveX object for use within Internet Explorer. GateKeeper (version 1) authentication was enabled. As the client did not specify a GUID, a random GateKeeper address was issued by the server. Directory (better known as FINDS) servers were created to distribute the load between servers. IRC4 - UNKNOWN. Further research is required. IRC5 GateKeeper (version 2) authentication was enabled. The major difference between v1 and v2 was that the client specified a GUID that was stored in the Windows Registry, which allowed each client to have a unique, and semi-permanent GateKeeper address. USER command is no longer required. GateKeeperPassport was enabled, this allowed the client to relay cookies received from the passport.net service as a method of permanent authentication. Non-passport nicknames must now be prefixed with a '>', which is displayed as 'Guest_' by the official client. Passport user nicknames are no longer able to be changed without first disconnecting. Guest nicknames may still be changed, but the official client offers no way to do so. Basic icons are shown next to the user's name, they identify MSN Staff (Sysops and Admins) with the MSN Butterfly, users who are away with a coffee cup, and spectators with a pair of glasses. IRC6 - IRC7: MSN Chat introduces profile icons, Profile icons indicated if the member had a profile, gender (if known), and if the user had a picture IRC8: As MSN Chat had now become a Subscription Only (Premium) service, This introduced extra user and channel modes. The channel mode 'S' was added to indicated that only subscribers could talk. The user mode 'B' (to indicate the user was subscribed)