This is a yielding function. When called, it will pause the Lua thread that called the function until a result is ready to be returned, without interrupting other scripts.
Returns the player’s rank in the group as an integer between 0 and 255, where 0 is a non-member and 255 is the group’s owner.
How to Check a Player's Rank in a Group
The code below will check if a player that has entered the game has a rank equal to 255, in a group with an ID of 2. If they are, it will print “Player is the owner of the group, ‘LOL’!”, otherwise “Player is NOT the owner of the group, ‘LOL’!” will be printed to the output.