Enter "735S653J" or "585A926D" as a code under the "Excusive Content" option at 
the main menu. If you entered the code correctly, a message will appear. This 
will unlock extra money for equipment in Single Player mode, extra money for 
character unlocking in Multiplayer mode, silver weapons in Multiplayer mode, and 
the Superb Ranger weapon that can be used during the first two chapters.