Map Feature: This feature has nothing to do with the level you are editing.
Here you can bring maps together.
The starting map starts at ( 0x, 0y ).
Now lets say the player reaches the right side of the map when on ( 0x, 0y ).
The map in ( 1x, 0y ) will now load as if they were connected.
Games loaded like this will keep track of all Key and Lock info across maps.
It's not very neat, but after you understand it you won't have any problems at all.