Indicates whether a map element should be match its rotation to the map itself, or to the user interface. For instance, the map itself may be rotated such that “up” matches the user’s aircraft, but you may want to draw a text label such that it is always rotated zero degrees relative to the user’s perspective. In that case, you would have it draw with UI orientation.

xplm_MapOrientation_Map"0" Orient such that a 0 degree rotation matches the map's north
xplm_MapOrientation_UI"1" Orient such that a 0 degree rotation is "up" relative to the user interface