Actually, it's enough to just change values in object editor for that unit.
Stats - Hide Minimap Icon
Stats - Hero - Hide minimap icon
You could also import custom minimap so people don't see your terrain.
The only disadvantage is that player may still see the quadrangle in minimap that represents what that player sees in game.
Import the attached file to your map with path: "war3mapMap.blp"
- Minimap will be totally black
- Quadrangle will also be gone
I was wondering if you don't trust me or that it will work. Here maybe a map file will convince you to test it. Anyway do as it pleases you.
I should eat my tongue now, it worked.
I'm really sorry, dude, really really.
next time don't judge a person by its rep..
Also why black?.. you can use let say a logo of your map because black is boring.. it still disable your terrain..