As well as handling and displaying -.-5 MHz and -.5KHz frequencies the Aerofly navigation system needs to be able to cope with the many German DME only stations at the German airports with ILS approaches without frequency paired DMEs. The current nav page does not display them.
The old DOS/Win 95 MSFS 4 and 5 readme.txt files were great sources of information in the dark ages. Tapping the airport in earlier Aeros brought up a nice information page.