German Aircraft in missions very often have wrong registraions.
Like this:
German civil aircraft (except gliders) never have a number in the registration.
They are always like this:
D-EGKH
D - for germany
E - the class of aircraft:
GKH - random letters
the “E” represents the class of aircraft.
Here is
A - Aircraft above 20t
B - Aircraft 14 - 20t
C - Aircraft 5.7t - 14t
E - single engine prop below 2 tons like C172
F - single Engine 2t - 5.7t
G - Multi Engine below 2t
H - Helicopter
I - Multi Engine 2t - 5.7t
K - motorized gliders
L - Blimp or Zeppelin
M - Microlight aircraft below 600kg, like CTLS, VL-3, Virus plane
O - Balloons
At least it would be nice, not to have numbers in the registration!