It dawned on me that I also didn't understand much about the non-com Ek2.
So I asked someone who has probably seen more original Ek documents then anyone
I know and is currently writing a book on the subject.
His answer to me was---
"Basic run down for 1914 cross non combattants ...
1) Anyone serving outside the borders of Germany, Clerics, medics, mechanics,
railwaymen, Govt officials... received a black ribbon. Whether under fire or not.
2) Govt officials, doctors ect within the borders of Germany got the white ribbon.
3) Military men within the borders of Germany, having done some meritoris MILITARY
service (no real bravery)could also get a black ribboned cross for service on the home front.
So a white ribboned cross was an official, doctor, ect working inside Germany."
Thanks very much to Chris for his help with this.