I've been looking at and comparing the various (seemingly endless) designs the German Junker planes had and noticed lots of them (but not all) have codes painted in large letters and numbers on the sides and sometimes on the wings. I'm having no luck researching what these were for or what they meant. Wondering if anyone can shed any light? Here are some examples of the codes I've seen:
12 AR
50 G10
RJ OP
HX
12 AF
32 V22
27 E11
53 F12
22 48
D-AGUK
Thank you for your time and help
There's a mix of markings there. "D-AGUK" is a civil aircraft registration, as can be seen on the German civil register. The five character codes are pre-war; according to Luftwaffe Colour Schemes and Markings 1935-1945 the first number represents a geographical command; the second character is the chronological order of the Geschwader (wing) formed within that command; the third character was the code of the individual aircraft within its Staffel (squadron), the fourth letter represents the Gruppe (group) and the fifth the Staffel. An example it gives uses the 27 + E11 marking - aircraft "E" within the first Staffel, I Gruppe, Kampfgeschwader 152 (the 7th Geschwader formed in Luftkreis II, Berlin).
The rather complex scheme changed in 1939 to the four character system, in which the first two characters identified the Geschwader, the third letter the individual aircraft in the Staffel, and the fourth letter the Staffel. See also Emmanuel Gustin's German Aircraft Markings from the Warbirds Resource Group.