How to Unban a Player From "Call of Duty 4"by Joshua PhillipsUpdated September 22, 2017
"Call of Duty 4" online is played by connecting to multiplayer servers. These servers are set up and run by other gamers, and as such come each comes with its own set of rules. Some rules may be no cursing, or no hacking or cheating. If you are running a server and have banned someone for violating one of your rules, you may give that player a second chance by unbanning him while on your server during a multiplayer match.
Press the "~" key. This opens a command console.
Type "/rcon unbanuser [NAME]" into the console, without the quotation marks. Replace [NAME] with the name of the player you wish to unban.
Press "Enter." You will receive a message within the console that the player has now been unbanned and will be able to join your server.