Putting an S instead of an N makes a difference?
Yup! That's the beauty of how it works! Even putting a 4 instead of a 9 makes a difference too! So by using N E S W and 0 1 2 3 4 5 6 7 8 9 in various combinations you can go anywhere in the world!
It is a truly versatile system, just like writing in fact - you Ntupid, Nilly Sumpty!