Black out a player's map that they have not yet visited. Also, show coordinates on map where mouse is.
Impossible with current game state.
Rust iO map shows coords when you right click on map and InfoPanel shows your present coords (if optioned) all the time, As for the "fog of war" effect with the map that was possible when everyone was using the same map (Legacy) but with the amount of procedural maps being used now i doubt it could be accomplished,
I suppose he was referring to the ingame map.