They don't differentiate 0 from O- Although when I learnt Morse Code (at a Swedish Army facility) together with a group of radio amateurs in the 70s, we were taught to slash the zeroes (contrary to the IBM mainframe people) and write the Es as reversed 3s. And Swedes always cross the 7s. About the letter '?' in Danish and Norwegian, which is written '?' in Swedish (with the r?ck d?ts) and pronounced 'er', it is obviously differentiated from Oh and zero in everyday writing by the slash or dots. What the Danish or Norwegian radio amateurs or mainframe people do to resolve the conflict they might have there, I have no idea. /Jonas