Object Markers - LlemonDuck/runelite GitHub Wiki
Object Markers Configuration
The Ground Markers plugin allows user to mark objects around the world. Marking objects can be done by holding the shift key and right clicking the object you want to mark and then click "Mark" in the menu.
Removing a marked objects follows the same principle, shift right click the object and select the menu option again to remove the object.
The plugin also remembers which objects you have marked between sessions.