How about some new map markers. Something other than N for note. Like a L for looted. V for vehicle. Some stuff that is easily readable just from looking at the map. Basically be just like a Note but with a different letter. Or allow the Letter shown from a N be definable. Though I tend to think L for looted should be a quick key one. 
Added with next version.
Note: L:TEXT will add a note with symbol L and text TEXT
Thanks!