Bukkit

Command : Permission : Description
/nick <nickname> : nick.nick : This command nick you to the nick name you with to use.
/nick <nickname> <player> : nick.nick.others : This command with nick name the player you input.
/unnick : nick.nick : This command will un-nick yourself.
/unnick <player> : nick.nick.others : This command will un-nick the player that you input.
/nickcheck <player> : nick.check : This command will check if the player (name or nick name) who you imputted is nicked and what they're nicked as.