Thanks for the link.

From memory, the public transport map of West Berlin was rather similar, except that they didn't need to hide an inconvenient hole in the middle. West Berlin's transport map would no doubt have ignored the existence of East Berlin altogether if West Berliners hadn't had access to some parts of Friedrichstrasse station as a border crossing and a transport interchange between two lines that crossed the Wall (and are missing, along with several closed stations, from the East Berlin map).

Of course, that wasn't the only example of carefully blind cartography. I well remember visiting the Harz in the mid-70s - both sides of the border on the same holiday. The only feature that showed up in both tourist brochures was the (rather hard to miss as the highest mountain in the range) Brocken - which, ironically, was not accessible to tourists from either side because it was in East Germany but almost on the border. Otherwise, the Harz just stopped at the border, from both directions.

I sometimes miss the old days.