Non-Directional Beacons (NDBs) in Denmark :
Besides the normal morse code, stations of scandinavian countries (DNK, S, NOR, FIN) have the following additional letters:
.-.- . = .Ä Æ
.--.- .= .Å
---.. = .Ö. Ø
See here 2 charts from the nautical handbook of 1951, showing all marine NDBs in Denmark, and the other countries around
NDBs connected with a black line operated on a 'time-shared' basis (each station 1 or 2 minutes), using the same frequency. They are all gone since about the end of the 1980s.
C