Say you've just downloaded a map, but you're still weary as to whether it will work, well the plan is simple.
Simple create a character, no need to put markings or anything. Name it what you'd like ex. 'Map Maker' and simply enter the map. If it doesn't work, just delete the charrie! It saves alot of time, too and it's what I always do when downloading a new map. ^ _ ^
Hope this helped any of chu floofies.