Inside
What does making a screen 'inside' actually do? And, are caves 'inside'?
If Dink has a map that shows his current location, it will not update when he enters a screen marked as "inside". If he enters a house, for example, it will look like Dink's still on the screen with the house even if he's actually somewhere completely different.
Oh, alright. Then, are caves inside? Or, how do I make it look (on a map) like Dink is in a cave?
Well if you want Dink's position to be the entrance of the cave, then you should mark all the cave screens as 'inside'. But if you want a map of the cave then you shouldn't mark them as inside and add an overview of the cave to the map.bmp file.
Eh, I doubt I'll make a map anyway. It's not much use for my D-Mod.