How do you use the marking map in Pokemon platinum?

Answer 1

If there are legendary Pokemon running around freely across Sinnoh, then it will show where they are. Note that whenever you go somewhere else (a new town, a new route, etc.) the Pokemon's position changes. If you happen to be lucky enough to be in the exact same area as the Pokemon, then go into any area where you encounter wild Pokemon and usually in the first couple of battles you will encounter the legendary Pokemon. Please note again that the second they can the Pokemon will try to flee from battle, so make sure that a speedy Pokemon who knows a move like Block is first in your party when you encounter the legendary Pokemon.

You can also use the Marking Map to mark places that you want to remember. To do this, simply drag one of the shapes from the bottom of the screen and put it anywhere on the map.

Good luck!