How it works:
/warn <player> <reason> - Warns the player with that reason
/warns <player> - Lists all of the player's warnings
/removewarn <player> <number> - Will remove the numbered warn
/clearwarns <player> - Clears all of the player's warns

Who can use what commands?
All ranks 1-5 can use the /warn command
All ranks 1-5 can use the /warns command
All ranks 1-4 can use the /removewarn command
All ranks 1-3 can use the /clearwarns command

Here is /warns when the player has the max amount of warnings


Here is when you /warn someone



When a player has 3 warnings and you /warn them, they will be kicked for exceeding the max warn amount. It will also tell you if the player has been previously kicked when you do /warns