[Kari Lumppio]

Hello!

First, thank you for all who have responded. Just back from four day journey so I haven't posted any replies.

In the mean time I received some addtional data (thanks!) and it seems the KGr 506 call-out letters I asked about are the individual letters from standard four-digit unit codes.

I base this on few things: the single letters for 3. Staffel do match to the two letter codes given in the technical report. Also there are same individual letters given for two staffel planes (in the example given by mr. Jones the "P3" stands for whole Gruppe?).

Also the KGr 506 KTB writes about a Ju 88 MIA "F / 2/506" and it turns out that the complete code for the plane was 8L+FK. That is 2/906 code, S4 would be for KGr 506. The 906 staffel seems to be attached to KGr 506 just before the transfer to Riga, September 1941.



For what it is worth. In the Finnish own flight (= German, Finnish & neutral) logs there sometimes do appear three letter codes - sometimes with the standard four-digit code - and IIRC they are sometimes marked as "kutsu" (=call sign). My impression has been that the three letter codes were (temporary?) radio call signs. Haven't seen anywhere any explanation and this is indeed a subject not covered anywhere that I know. I have not collected that data either nor do have any notes of them at the moment.


Regards,
Kari