Back in Feb. 2023 on this thread was a discussion of the spelling of the German city KOLN, known also as COLOGNE.
The German city was spelled as COLN and sometime after the 1901 spelling reform was changed to KOLN.
I have found an image of a German post card from WW1 dated Dec. 20, 1916, and post marked as COLN.
It seems there was a long transition period before the spelling change was adopted by the German post office.
Last edited by C. Wetzel-20609; 09/07/2023 08:45 PM.
