Me, I always use the degrees/decimal minutes (N00° 00.00') which I thought had become the standard in Europe, but as you know there are many ways to show it.
Google maps (American I suppose) uses both decimal degrees (marine/scientific standard?) or degrees, mins and secs to a decimal point.
-10° 32' 6.25", -138° 38' 40.97"
I suppose the marine should be most foolproof, but then people miss out the - (minus, = W of meridian or S of equator) so I suppose there will always be misunderstandings. I often see waypoints written incorrectly on accom' websites.