[SteveB]

Not wishing to distract everybody but having thought I had a bit of a grip on this system through the ETO Maps site I am now confused by the map posted by mhuxt.

Clearly the "Danube Zone" does not appear as a separate grid system on the ETO Maps site but as far I can tell seems to have been absorbed into the "Nord de Guerre Zone".

But more importantly on the map posted by mhuxt it seems that not all the small squares have a code letter. In the red area "Danube Zone" around the large letter 'S' there are a number of squares that have no small code letter.

Steve