Terrain Marker(s)

(1) Click a truck, then hold CTRL and click on the spot on the map that
    you want to mark.

(2) Next, hold ALT and the key that you want for that spot.
    EXAMPLE: ALT N  (for a place at the north part of map)

(3) EXAMPLE: SHIFT N would take you to that spot on map (north map area).

NOTE: 
You can have more than 1 Terrain Marker.

HINT:
Terrain markers are handy for your outposts and enemy outposts on stock
maps (original fight for oil maps that came with the game).