A Google search for "n e z coordinates" revealed that N stands for north or northings, E stands for east or eastings. Basically, it looks like they just swap X and Y.

I'm South African and I've never seen that used. Perhaps it is by people in a particular industry?

South Africa has a novel coordinate system, at least for people who expect North to be at the top and east on the X axis.

Yes just a simple swap, except every dialog, grid control, status bar and tooltip has to keep track of which way round they are.

I didn't mean to say it would be easy to support in any given software package :)