The emblem was changed to a new one in 1939 and the version of the flag charged with that new emblem is still in use. Christian Fogd Pedersen notes that the post ensign is only used by vessels actually carrying mail. When they are not, they do not have the right to fly the ensign. He also notes that the flag is used on land by postal authorities. One interesting fact mentioned by Pedersen is that only larger mail carrying vessels use the swallow-tailed post flag.
Smaller boats use a rectangular ensign with the emblem in the canton.
The vessels using the ensign was charged with maintaining light houses and light ships, sea marks, etc. Royal resolution of 8 September 1916 extended the use of the ensign to the pilot service as well. The flag is listed in Christian Fogd Pedersen's 1979 flag book, and is presumably still in use. The flag of the Danish State Railways was originally introduced on 27 April 1887, presumably with the emblem shown in the Flaggenbuch. The letters 'LM' is for Landbrugsministeriet, that is Ministry of Agriculture.