Credits: Death_Aruban
Five ranks are included from the start but you can add more manually: Admin, Moderator, Helper, Builder, VIP.
How to assign ranks to the players
Start by assigning the admin rank to yourself with the following command: "/tag @s add admin". You can then proceed to edit other players' ranks through the special menu. Use the command "-rank add" to open the menu. Type "-rank remove" to strip players of their rank. Use "-rank list" to check the current status of the ranks and "-rank help" if you have any troubles.