General syntax
Commands for the Worlds plugin always begin with /worlds (or use /ws, which is shorter).
List worlds
/worlds list
Create new world
/worlds create <worldname>
Removing, loading and unloading
/worlds remove <worldname>
Teleporting
/worlds teleport <worldname>
Copy and rename
/worlds copy <from> <to>
Set control flags
Using the Forms GUI
Control lists
Learn more about control lists here.
Unset flags
/worlds unset <flag>
Default flags
For default flags, the commands are nearly identical to the ones to set flags for the current world. Just add defaults behind /worlds and use the commands from set, control lists and unset.