MinecraftForge/MinecraftForge — pull request #878 by jk-5 (2013-12-01 11:00:41+00:00)
Title: Added an event that can be used for modifying the join/leave messages

Subscribe to either ```PlayerMessageEvent.JoinServer``` or ```PlayerMessageEvent.LeaveServer```, and use the ```message``` field to modify the message, or cancel the event to not show any message.

It would be nice to have this in 1.6.4, but if you guys are too busy with the update, just let it wait till 1.7